Bis2B Final Study Guide

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 7. The intertropical convergence zone (ITCZ) is ________________________. (define). Where moist air is picked up and then rises to produce cool air that comes down as precipitation. In july, it’s north of the equator - Area of intense rainfall in Hadley Cell circulation 8. Why does the vegetation on the west slope of the Sierra look very different from the vegetation at the same elevation on the east slope? Be sure to explain what drives the climate differences between the east and west slopes. Warm air comes from the west and as it goes up in elevation it cools and precipitates and when it goes to the eastern side the dry air cools and sinks, leaving that area dry. This is called the rainshadow effect. 2 9. Which of the following is closest to the number of likely number of species on Earth: a. 100,000 b. 1,000,000 c. 10,000,000 d. 100,000,000 e. 1,000,000,000 [Be sure you understand generally where such a number comes from... while we would not require you to replicate calculations, you should know the general approaches that are used to estimate global diversity] - Use data from part of the Earth to make assumptions to estimate the number of species in the world. - EXAMPLE: - Extrapolation from known floras and faunas: - (# butterflies in Britain/# insects in Britain) = (# butterflies on Earth/#insects on Earth) - (67/22000) = (15000/#insects on earth) = 4.9 million insects on Earth. - SO...if about half of the species on Earth are insects, there must be about 10 million total species on Earth. 10. A criticism of the morphological species concept is... A. many species only reproduce asexually B species’ morphology can be influenced by the environment C. it is simple to apply D. breeding experiments are difficult to conduct E. species that look the same must be closely related 11. You are a consultant for the government on the small island nation of Aggielandia in the south Pacific, which has a total area of 80km^2. Half the island has been converted from natural forest for human uses such as agriculture and housing. The government 1. 2. l3 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - LECTURE 3-4 QUESTIONS (labeled 4-6 on Canvas) 1. Contrast autotrophs and heterotrophs in terms of how they acquire energy and nutrients. - autotrophs: make energy from inorganic materials and can live exclusively on inorganic sources of carbon, nitrogen, and other essential resources + Eg. Algae - Photoautotrophs: use light to make energy from inorganic material - Heterotrophs: derive energy from other organisms/use pre-formed organic molecules + Eg. Consumers (eg. deer, sharks, lions) i. Herbivores - consume plant material ii. Carnivores - attack and consume animal material iii. Omnivores - consume both plant and animal material iv. Detritivores - consume dead plant or animal matter OR v. Suspension Feeder - remove suspended particles from water vi. Deposit Feeders - consume dead organic matter vii. Predator - active hunter of live organisms viii. Symbiont - live in, with, or on another organism and obtain nutrition from that organism (host). Parasitic (benefits come at expense of host) OR mutualist (host benefits as well) 2. Which of the following is the best answer to why plants on land are green (a) green is the color of life (b) chlorophyll absorbs green light (c ) Chlorophyll absorbs red and blue light (d) herbivores are repelled by the color green (e) it’s not easy being green 3. Describe two ways (two different things you could measure) to estimate the rate of photosynthesis in a particular plant. You could measure the amount of oxygen and amount of carbon dioxide concentration around the air of that plant dd Two ways to measure photosynthesis in a plant are to measure either a. production of oxygen or, b. uptake of carbon dioxide (6CO2+6H20 → C6H1206+602) + Respiration is the same process but the second half leads to the first half. 1. 2. l6 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 8. Based on these data which size class of prey would you predict would be preferred by the crab if the crab forages to maximize energy intake per unit time? - They would eat 3cm snails because they get more energy for less handling time + Benefit outweighs the cost 9. If crabs preferred snails in size class #1, what explanation might you offer for what other ecological factor determines prey choice. - They might be more abundance, or easier to find 10. What is the greenhouse effect? Given the greenhouse effect, what are the likely consequences of humans burning “fossil fuels” in terms of global temperature? - Greenhouse gases trap the light/heat given off by the sun into a layer of the earth and it reflects back, but some of that heat is being kept in and making the temperature rise; gases are like CH4 and CO2; the more fossil fuels burned the more gases given off and those trap the heat + Leads to a.) increasing CO2 = warmer temp. b.) leads to increase transpiration c.) also may change the Hadley Cells and their precipitation 11. Describe the evidence that humans are causing climate warming. - The atmospheric concentration of C14 has decreased w/ the burning of fossil fuel, becoming more and more dilute. Dilution occurs due to the additions of C12 and C13. - Strong correlation between CO2 and temperature, satellites show less radiation coming off the earth. Evidence of global warming is more severe weather, the melting of ice caps, dirtier air, wildlife extinction rates, and higher sea levels. 1. 2. l9 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - D. density dependent vs. density independent density independent factors exert effects on a population no matter how dense the population is whereas density dependent factors arise and intensify with an increase in population. E. carrying capacity (K): the maximum population size that can be supported by available resources or physical space F. Demography: a study of the vital statistics (birth, death) of a population and how they vary with age. G. life table: vital statistics related to life expectancy and mortality of a species. H. age specific survivorship: a. Type 1: low mortality until the later stages of life (mammals) b. Type 2: probability of surviving until the next year is independent of age (birds) c. Type 3: high juvenile mortality but low adult mortality (insects, plants, turtles, marine invertebrates) I. age specific fecundity: Fecundity (Mx) - average number of offspring produced by individual of age x J. net reproductive rate: (R 0 ) = average number of offspring produced by an individual during its entire lifetime - The product of survival and fecundity, summed over all age classes 3. Explain the difference between r and Ro. Under which values of each is population growth positive, negative, and zero? r is the intrinsic rate of growth (birth-death). R0 is the average number of offspring produced by an individual during its entire lifetime. If R0>1, the population is growing. R0<1 the population is decreasing. If R0=1, the population is remaining constant. r>0 pop growth, r <0 shrinking pop, r=0 same size. 4. Explain how a finite availability of resources can produce density dependent population growth. What other factors can cause density dependence? A finite availability of resources can produce a density dependent population growth since the number of species that will survive in the population is dependent on resources (food, water, shelter, etc). Disease and migration are also density dependent. 5. Identify the four fundamental processes that dictate whether a population is growing or declining, and define an open versus closed population in terms of these processes. The four fundamental processes that dictate whether a population is growing and declining are births, deaths, immigrants, and emigrants. If a population is closed, it does not account for immigrants and emigrants. 6. Which of the following limit logistic population growth? (*logistic growth = density dependent) 1. 2. l12 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - A. How is the population of ducks changing in size over time? R 0 = 1.0(0) + 0.25(0) + 0.20(3.0) + 0.1(7.0) + 0.1(0) = 1.3, R 0 > 1, increasing B. What type of survivorship curve would you say this species has? Type 3 I would argue that this species has Type 1 survivorship curve because of the number of hatchlings surviving → old adults surviving decreases, especially from hatchling to juvenile. C. If you were hired as head of grounds for UCD and wanted to stabilize the population size (prevent extinction and prevent the population from increasing) what specific approach might you take with this population? Consider what specific age class is most critical to focus your efforts on and what action you might take (alter survival vs. fecundity) Change the fecundity of adults to zero. Stabilize population R 0 = 1 → just reduce the fecundity rate of adult duck from 7.0 → 4.0 → R 0 = 0 + 0.6 + 0.4 + 0 = 1 → stabilize population. If we completely cut out the adult fecundity rate, R 0 = 0.6 <1 → the population would be heading for extinction 11. Sketch a graph of logistic population growth. Label axes and indicate where K occurs in the graph. 1. 2. l15 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - g. Homology: possessing a shared ancestor, resulting in similar characteristics h. Analogy: similar characteristics between unrelated organisms resulting from convergent evolution i. Adaptation (state of being): a trait that increase an organism's fitness and reproductive success j. Acclimation: a short term phenotypic change that resulted from an organism’s environment, often reversible. Can occur within an individual’s lifetime k. Phenotypic plasticity: some organisms can change their appearance, development, and physiology in an environment 7. Summarize the major contributions of the following scientists to evolutionary biology. a. Charles Lyell: geological uniformitarianism ‘the present is the key to the past’ + Eg. the Grand Canyon (built up layers of rock, gradual changes lead to a large outcome) b. Jean Baptiste Lamarck: i. Principle of use and disuse: disuse → vestigal organs, use → adaptation ii. Inheritance of acquired (through use and disuse) characteristics c. Alfred Russel Wallace: came up with basically the same theory as darwin and wrote “The origin of species by means of natural selection or the preservation of favoured races in the struggle for existence” with darwin d. Thomas malthus: Darwin read his essay on The Principle of Population which led him to understand that the “struggle for existence” applied to all organisms (not just humans) e. Gregor Mendel: an austrian monk who discovered the basics of heredity through work in his garden (the pea guy who crossed wrinkled and smooth peas) 8. What is the major difference between a transformational theory of evolution and a variational theory? Draw a diagram that distinguishes the two. Is the Darwin/Wallace theory transformational or variational? How does a variational theory differ from a-typological/essentialist (Platonic Ideal) approach? Transformational (Lamarckian) theory: transformations occur WITHIN generations and are subsequently modified by environment. Variational (Darwinian) theory: differential survival/reproduction of individuals with different heritable traits. A typological view is where they have phenotypic variation because they deviate from the original “type” and we see that as a flaw. 9. True/False: By the time Darwin returned from the Voyage of the Beagle, he had developed the theory of evolution by natural selection. False 1. 2. l18 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - stem and branches of saguaros. Water loss is further minimized by a waxy covering on the “skin” of saguaro. Beneath the ground, saguaros have an extensive root system—much longer than plants living in wetter climates. These roots are also remarkably shallow. Most of them are only a few inches below the surface of the ground. This enables saguaros to absorb water from rainfall before it evaporates back into the air. (Image from National Geographic) 21. Which of the following is the best description of how saguaro cacti evolved to have long roots? a) Saguaro cacti needed to develop longer roots to survive in the desert b) Mutations occurred because the climate of Arizona and Mexico was hot c) Saguaros with short roots produced fewer seeds each year than saguaros with longer roots d) Each generation of saguaro cacti worked hard to grow roots as long as possible e) Changes like this depend on many factors, so it is impossible to answer 22. During the time period when saguaro cacti were evolving to their current form, there were years with very little rain. What likely happened to the saguaro cacti during the driest years? a) The saguaro cacti managed to obtain the water they needed b) Saguaro cacti with the shortest roots died c) The saguaro cacti survived with less water than normal d) The saguaro cacti grew longer roots 23. Every individual plant and animal is affected by the environment during its lifetime. For example, a tree will grow slanted if it lives on a windy ridge. What role did the responses of individuals to their environment play in the evolution of waxy skin among saguaro cacti? a) Responses like these were the sole reason saguaro cacti evolved waxy skin b) Responses like these contributed to saguaro cacti evolving waxy skin c) Responses like these played no role in the evolution of waxy skin in saguaro cacti d) Responses like these might have played a role in the evolution of cacti – if saguaro responded to intense sunlight or drought by growing waxier skin 24. A large population of saguaro cacti thrives in a wide valley in Southern Arizona. The valley floor is flat and there are no gullies, rock outcrops, or variation in the soil. Which of the following statements best describes similarities and differences among full-grown saguaro cacti living in the valley? a) The saguaro cacti share all the same traits and are essentially identical to each other b) The saguaro cacti share all of the most important traits, and the small differences between them do not affect how long they live or how well they reproduce c) The saguaro cacti are all identical on the inside, but have many differences in appearance. 1. 2. l21 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - d) The saguaro cacti share many important traits, but also have differences that may affect how long they live or how well they reproduce 25. The ancestors of modern saguaro cacti did not have long and sharp spines. Consider the first ancestor of saguaro cacti to grow spines that were as long and sharp as the spines on saguaro cacti living in Arizona today. Why did this cactus grow such sharp spines? a) It was fortunate a genetic mistake gave it extra sharp spines<<<<< b) The cactus needed sharper spines to stop animals from eating it c) Animals chewing on the cactus caused it to grow sharper spines d) Mutations changed the DNA of this cacti because it was injured by an animal e) The hot climate caused this change 26. Saguaro cacti produce fruits that contain thousands of seeds. These seeds are often eaten by birds. When a seed is eaten, it passes through the bird’s digestive system unharmed and falls to the ground. If a seed lands in suitable soil, escapes being eaten by mice, and receives enough rainfall during the first years of its life, it may eventually grow into a seedling. Which of the following is the best description of what influences whether saguaro cacti produce seedlings? a) The production of seedlings is purely a matter of chance b) Chance plays a big role, but the characteristics of individual cacti are also important c) The production of seedlings is not influenced by chance 27. Can you reconstruct the logic of the theory of natural selection (i.e., the necessary and sufficient conditions) and relate a biological example to that logical structure? Do you understand how to read the graphs that do (or don’t) substantiate whether the necessary and sufficient conditions are met? Are you sure??? Go through BOTH examples presented in lecture, and make sure you can clearly explain, based on the data, how natural selection works (i.e., How are all 4 conditions met?) . Goannas are large (2 m) monitor lizards that eat birds, eggs, small children, and toads. When poisonous cane toads were introduced into Australia, most goannas that ate them died. You know that there is naturally occurring variation in the population of goannas for tolerance to toad poison, and that some of that variation has a genetic basis. After a number of generations, you observe that the fraction of goannas dying from toad poisoning is declining, although the size of the goanna population has remained constant for hundreds of generations, and females continue to give birth to 7-35 offspring nearly every year of their lives. You don't know why this fraction is declining, but you notice that goannas continue to eat toads, and you suspect that natural selection has something to do with it. a) Name 1 (one) trait in the goannas that evolved by natural selection that can explain the declining incidence of toad-induced deaths. Trait: Resistance to cane toad toxin. 1. 2. l22 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - b) In addition to reproduction, briefly list the (three) additional general conditions necessary for natural selection to have caused the evolution of this trait, and how these conditions could be met in this example. 1. Phenotypic Variation: Individuals within a population must vary phenotypically a. There is naturally occurring variation in the population of goannas for tolerance to toad poison, and that some of that variation has a genetic basis.?? 2. Heritability: individuals pass at least some of their traits to their offspring. a. Need prove that individuals who are resistant to toad toxin are reproducing more successfully than individuals who are not resistant to toad toxin. 3. Fitness: Individuals with different traits differ in their survival or reproductive success a. Individuals within the goannas population who are resistant to cane toad toxin has a higher fitness than individuals who are not during times when there are cane toads. c) You manage to eradicate all of the cane toads, and you discover that the frequency of goannas resistant to toad poison rapidly decreases. How can the concept of a trade-off help to explain this change? The trade-off is that having a resistance to toad poison takes away the ability to do something else such as finding nutrients. So when there is no cane toads in the environment, individuals without the trait will have higher fitness. LECTURE 11-12 QUESTIONS 1. List the genotypes of all the different gametes that could be formed by an individual with the genotype RrSsTt. RST RSt RsT Rst rST rSt rsT rst 2. If an adult male has the genotype AABbcc, list all the possible sperm genotypes that could be produced by this male. 1. 2. l23 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - ABc, Abc 3. How many different possible egg genotypes could be made by a female with the genotype RRssTt? Rst RsT 4. Give two examples of phenotypic traits controlled by multiple (more than two) alleles: a) Dog’s coat color b) Human Hair color c) skin color 5. Plant pollen is analogous to animal _____________. sperm 6. Set up a Punnett square for a cross between two groups of birds. One group is homozygous recessive for feather color (they are pink), and the other group is heterozygous and expresses the dominant blue allele. Both groups are heterozygous for scaly legs and they express scaly, not smooth, legs. List the genotypes that could be produced from a cross between the members of the two groups, and list the phenotypes resulting from each genotype. Give the expected ratios for genotypes and phenotypes in the offspring generation, assuming that the color gene and the scaly gene occur on different chromosomes. 7. An unfertilized chicken egg contains 39 chromosomes. In this species, N = 39 _____________ and 2N = 78 ____________. Cells taken from a chicken feather have 78 _________ chromosomes. 8. What is recombination and how does it work? Is it the same thing as crossing-over? If an organism practiced self-fertilization, could recombination occur? If an organism practiced self-fertilization, would all of its offspring be genetically identical? Why/why not? “If we observe a recombinant frequency of 50 percent in a testcross, we can infer that the two genes under study assort independently.” [http://www.ncbi.nlm.nih.gov/books/NBK21889/] Found this online...my understanding is that Recombination occurs as a result of crossing over in meiosis and the law of independent assortment (if it is being applied to the problem) is related in the sense that when cells undergo crossing over in meiosis, we assume that the recombination frequency will support the law of independent assortment (assort independently) and this assumption allows us to utilize tools like punnett squares to try and predict offspring 1. 2. l24 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - traits. *****I may be wrong, but my basic understanding is that none of those terms are necessarily exclusive of each other Self-fertilization does go through meiosis so therefore can have recombination. If an organism practices self-fertilization, recombination would occur if they are heterozygous for that gene. With self fertilization, two of the haploid daughter cells come together to form a haploid zygote and since there are 2 gametes, there are four different genetic combinations. Since the organism could be heterozygous, not all of the offspring would be genetically identical since there are four possible combinations when the two haploid daughter cells come together. If the individual was homozygous for all the genes it had, then yes, all the offspring would be genetically identical. ^ How is genetically identical similar to recombination? I thought recombination meant that the offsprings will have some alleles that the parents didn’t have...so would they be genetically identical within the offsprings? (I was thinking no)The children must only have alleles provided by their parents, they might just have different genotypes due to the crossing over of homologous chromosomes. 9. When a gene has several different versions that create slightly different gene products, each version of the gene is called an allele ______________. 10. If a female has the genotype AABbCc, what is the probability that any one of her gametes will have the genotype ABC? a) 1/2 b) 1/4 c) 1/8 d) 1/16 e)1 11. Explain how it is possible for a cross between two plants, one with red flowers and one with white flowers, to produce all pink-flowered offspring, when a cross between two pink-flowered plants produces pink-, white- and red-flowered offspring. Codominance Actually, it’s incomplete dominance. If it was codominance then the flower would be both red and white rather than pink. 12. Define the following terms: Genotype: the genetic composition of an organism Homozygote: if an individual’s genotype at a locus (the physical location of a gene on a chromosome) has two identical copies of an allele (SS or ss) Phenotype: the physical appearance of an organism as a result of the interaction of its genotype and the environment wd Dominant: Gene: the “particles” or “factors” Recessive: Pleiotropy: the production of a single gene of two or more apparently unrelated effects Epistasis: the interaction of genes that are not alleles, in particular the suppression of the effect of one such gene by another. 1. 2. l25 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - locus; a fixed position on a chromosome, like the position of a gene or a marker (genetic marker) Heterozygote; an individual having two different alleles of a particular gene or genes, and so giving rise to varying offspring. allele; different variants of a gene 13. If chickens with black feathers are crossed with chickens with white-splashed feathers, the F1 generation has gray feathers. This is an example of … a) overdominance b) Mendel's second law c) incomplete dominance d) the law of segregation e) independent assortment 14. If a budgerigar (a little bird) with the genotype YY (green feathers) is crossed with a budgerigar with the genotype yy (blue feathers), the offspring all have green feathers. In what ways are these two examples (see #13) similar? How are they different? The two examples are similar as there are two homozygous crosses, but are different as the heterozygous offspring do not have a new phenotype as they all express the dominant green feather allele and not an incomplete dominant blue-green phenotype. In both cases, they both reproduce to form all heterozygous offspring, but in #13, the alleles display incomplete dominance, so they create an intermediate form, while in this example, the green allele is dominant and overpowers the blue allele and the heterozygotes created are not incompletely dominant. They are completely dominant and create all green offspring. 15. The allele responsible for the peculiar markings of Siamese cats is also responsible for crossed-eyes and excessive meowing that occur in many members of this breed. This example best illustrates which of the following general principles: a) quantitative genetics b) heterozygote advantage c) pleiotropy d) the law of segregation e) codominance f) linkage g) a and c h) a, b, and d 16. Imagine that you are a budgerigar breeder, and someone presents you with a flock of budgerigars with wild-type markings (green). However, they neglect to tell you whether the birds are homozygous or heterozygous at the Y locus. 1. 2. l26 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - a) Design a "test cross" that would unambiguously tell you whether these birds were homozygotes or heterozygotes. USE HOMOZYGOUS RECESSIVE b) Use Punnett squares to show the expected genotypic ratios from your test cross if: 1) these birds were homozygotes. 100% green 2) these birds were heterozygotes. 50% green 17. In terms of Mendel’s discoveries about inheritance, how is possible for two individuals to have different genotypes and the same phenotype? The idea of dominant and recessive alleles allows for this to occur. When one allele is dominant over another, the genotype homozygous or heterozygous with the dominant allele present will be expressed phenotypically a) How could two individuals have the same genotype, but different phenotypes? The environment because the phenotype can be affected by it, pleiotropy- interactions between alleles at the same locus (dominant vs recessive), and the interactions between alleles at different loci (epistasis) 18. What is the difference between quantitative (or polygenic traits) and mendelian traits? Give examples of each. Mendelian inheritance only account for one gene affecting a trait. For example, there is only one gene that determines if a pea plant's flower will be white or purple, wrinkled or smooth. On the other hand, quantitative or polygenic inheritance (remember this for the midterm!)refers to more than one gene affecting a trait. For example, there are dozens of individual traits in your DNA that collectively determine your hair color. (Polygenic inheritance explains why there are thousands of natural shades of hair color and skin color) These are continuous traits Does the environment play any role in this? YES. Quantitative traits are also influenced by the environment. 19. How is genetic variation introduced into natural populations? How do recombination, segregation, independent assortment, and fertilization affect patterns of genetic variation? 21. Recombination can only occur between two (or more) _______________, ___________ of which is/are _______________. a) locuses; one; homozygous b) loci; both; heterozygous c) locata; both; heterozygous d) loci, one; heterozygous e) locis; both; heterozygous 22. You are interested in the inheritance of body color (the B-locus) and wing shape (the W locus) in house flies (NOT fruit flies). At the body color locus, the B-allele (gray body) is dominant to the b-allele (black body). At the wing shape locus, the W-allele (normal wings) is 1. 2. l27 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - dominant to the w-allele (vestigial, or shriveled wings). You perform the following dihybrid cross between two flies, one of which has a gray body and normal wings (genotype: BbWw), the other of which has a black body and vestigial wings (bbww). In the F1’s, you observe the following genotype frequencies: BbWw: 103 bbww: 115 Bbww: 111 bbWw: 114 The simplest interpretation of these data is that… a) the body color locus and the wing shape locus have epistatic effects. b) Mendel’s 2nd law of independent assortment is somehow violated. c) the body color locus and the wing shape locus have pleiotropic effects. d) the parents are highly inbred. e) the body color locus and the wing shape locus assort independently LECTURE 13-16 QUESTIONS 1. A population of peppered moths has the following genotypic frequencies: aa: 0.16, Aa: 0.04, AA: 0.80. The frequency of the 'a' allele in this population is… 0.18 Þ Is this population in Hardy-Weinberg equilibrium? [show your work for full credit] sqrt(.16) does not equal sqrt(.18) so it’s not in hardy-weinberg equilibrium 2. Our local land snail comes in two basic colors: brown-striped and black-striped. Color is determined by alleles at a single locus, where the black allele is dominant to the brown allele. Last week, you collected 1000 snails from your garden in Davis: 64% of these snails were brown, and 36% were black. Based on these data, you conclude that the frequency of the black allele in your garden population is… a) 0.40 b) 0.60 c) 0.20 d) 0.80 e) You can’t tell from the information given. 3. If the frequency of the C allele is 0.2 in a population with only 2 alleles at this locus, what will the frequency of heterozygotes be if the population is in Hardy-Weinberg equilibrium? a) 0.04 b) 0.16 c) 0.32 d) 0.64 e) 0.80 C= 0.2 c=0.8 1. 2. l28 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - heterozygous= 2pq= 2(.2)(.8)= .32 4. A moth has three alleles at a locus that controls antenna color: X1, X2 and X3. X1 is dominant to X2 and X3; X1 produces red antennae. X2 is co-dominant to X3; X2X2 produces yellow antennae, X3X3 produces white antennae, and X2X3 produces light yellow antennae. The phenotypic frequencies in a population are as follows: 0.04 WHITE 0.16 LIGHT YELLOW 0.16 YELLOW 0.64 RED Þ Assuming that this population is in Hardy-Weinberg equilibrium, what is the frequency of the X3 allele in this population? a) 0.04 b) 0.20 c) 0.16 d) 0.32 e) 0.64 5. You measure the allele frequencies in the parental generation of a cheetah population, and find that f(A) is 0.6. There are only two alleles at this locus. In the next generation of cheetahs you find the following genotype frequencies: f(AA) = 0.36, f(Aa) = 0.48, f(aa) = 0.16. Which assumption of Hardy-Weinberg equilibrium is likely being violated? a) random mating b) large population size c) no advantage to particular alleles d) b and c e) none of the assumptions is violated 6. Imagine a population of frogs with 2 color morphs (forms); green (genotypes Gg and GG) and yellow (genotype gg). The population is initially in Hardy-Weinberg equilibrium. Then, frogs begin to mate assortatively for color. After one generation of positive assortative mating, you would expect to observe a change in… a) the number of eggs laid. b) the genotypic frequencies. c) the population size. d) the number of offspring produced. e) all of the above. 7. You know that a population of elk has 2 alleles, E and e, at a single locus that controls the color of a rump patch. The frequency of allele E, p(E) = 0.10 in the parental generation. In the offspring of this parental generation, the genotypic frequencies are EE = 0.01, Ee = 0.18, and ee = 0.81. You suspect that… a) the population is in Hardy-Weinberg equilibrium. b) elk are mating with close relatives. c) the elk are preferentially mating with individuals with the same color patch. 1. 2. l29 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - d) heterozygotes have lower relative fitness than ee genotypes. e) ee genotypes have higher relative fitness than other genotypes. 8. One of the major eye color in humans has 2 alleles, b and B. The frequency of the bb genotype is 0.36. If the population is in Hardy-Weinberg equilibrium, the frequency of the B allele should be… a) 0.04 b) 0.18 c) 0.40 d) 0.60 e) 0.64 9. (a) Imagine a population of birds living on an island near the mainland. If 6 birds from the mainland join the island population, which assumption of the Hardy-Weinberg model will be violated? _____________________________________ No Gene Flow Five Assumptions: no gene flow, no mutations, no selection, random mating, infinite population size (b) Historically, the population of California Condors probably numbered in the thousands of birds. However, because of human use of pesticides, hunting, and habitat destruction, the population declined to no more than 13 individuals. Now, thanks to captive breeding, re-introduction programs, pesticide control, and habitat preservation, the population is increasing in size. What would you predict would be the primary difference in numbers of alleles per locus and allelic frequencies in the pre-historic versus modern (recovered) populations of condors? The number of alleles would decrease by a lot Frequencies would be different due to lack of variation (c) What process likely caused this difference? Genetic drift- population bottleneck (d) Which assumption of Hardy-Weinberg equilibrium is being violated in cases (b) and (c) above? Large population size (e) If the California Condors choose to mate on the basis of tail length, which assumption of Hardy Weinberg equilibrium would be violated? Random Mating 10. A population of a marine snail at Bodega Bay has 4 alleles at a locus that controls shell color. Each genotype expresses a unique color. What is the maximum number of phenotypes in the population? a) 4 b) 6 1. 2. l30 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - c) 10 d) 64 e) 256 Formula: n(n+1)/2, where n= #of alleles at a locus 11. A population of plants has 2 alleles, P and p, at a locus controlling petal color: f(P) = 0.60 and f(p) = 0.4. When you study the frequency of heterozygotes in the population you find that f(Pp) = 0.24. This would be expected if… a) the population is in Hardy-Weinberg equilibrium. b) the plants self-fertilize. c) the population has gone through a bottleneck. d) heterozygotes are fitter than homozygotes. e) the P allele is dominant to the p allele. The expected frequency of Pp under the equilibrium would be 0.48. Since the observed frequency is much lower, the frequency of the homozygotes must have increased. Inbreeding caused a decrease in the frequency of heterozygotes by a factor of 2 and an increase in the frequency of homozygotes. So self-fertilizing, which of course is the most extreme form of inbreeding. 12. A population of cats has the following genotype frequencies at a locus controlling spotting pattern: ss: 0.36, Ss: 0.04, SS: 0.60. (a) The frequency of the S allele in this population is___________ [show your work for full credit] 0.62 F(S)= F(SS)+½ F(Ss) F(S)= .6+.02 = .62 (b) Is this population in Hardy-Weinberg equilibrium? [show your work for full credit] No, because the two numbers don’t match [f(S)]^2 = f(SS)=(.62)^2 .38≠.6 13. In a natural population of 1252 wild radish plants at the UC Davis airport, you notice that there are two flower colors, red and white. You breed the plants in the lab, and show that flower color is controlled by a single gene with two alleles. The red allele is dominant to the white allele. You go back out to the airport and notice that both honeybees and bumblebees pollinate the radish flowers. The bumblebees primarily visit white-flowered plants, but sometimes visit red-flowered plants also. The honeybees primarily visit red-flowered plants, but sometimes visit white-flowered plants. You are asked to estimate the genotypic and allelic frequencies at the flower color locus in the Airport population. You need to do this accurately and efficiently, you should… a) count only red-flowered plants. b) count only white-flowered plants. c) count both red-flowered and white-flowered plants. 1. 2. l31 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - d) count the numbers of bumblebees and honeybees. e) none of the above. 14. Give a simple genetic definition of evolution. How does this differ from a purely phenotypic definition of evolution? Evolution is the changes in the heritable properties of groups of individuals over the course of generations. A phenotypic definition would be the changes in physical characteristics of a population over time. The difference is that not all phenotypes can be inherited. 15. From an evolutionary perspective, which of the following is the most appropriate level for measuring genetic variation: (1) the cell; (2) the individual; (3) the population; (4) the community; (5) the ecosystem? Why did you choose the answer that you did? 16. At which level of biological organization is it most appropriate to use the term "adaptation": individuals, populations, species, communities? Why did you choose your answer? Does it matter whether you define adaptation as a process or a state of being? If its a process, it’s a population If its a state of being then its an individual/population 17. Which of the following statement is not true about allele frequencies? a) The sum of all allele frequencies at a locus is 1. b) If there are two alleles at a locus, and we know the frequency of one of them, we can obtain the frequency of the other by subtraction. c) If an allele is absent from a population, its frequency is 0. d) If two populations have the same alleles, they will have the same allelic frequencies. e) If there is only one allele at a locus, its frequency is 1. 18. Which of the following processes is LEAST likely to change ALLELIC frequencies? Why or why not? a) Inbreeding b) Mutation c) Genetic Drift d) Gene Flow e) Directional Selection 19. Natural selection that preserves mean phenotypic values for a trait is called… a) unidirectional selection. b) bidirectional selection. c) correcting selection. d) stabilizing selection. 1. 2. l32 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - e) sexual selection. 20. In terms of genetic control, what is the basic difference between traits that exhibit continuous variation versus discrete variation? Number of loci that contribute to the trait Continuous: quantitative, affected by environmental factors there’s multiple values (extending from one end to another) ex: height Discrete: the one with a certain value, it’s limited barely any effect from the environment ex: blood type Continuous is quantitative discrete is qualitative 21. In nature, there is never truly random mating, populations are finite, individuals carry genes from population to population, mutations occur, and natural selection acts. Why, then, does it make any sense for evolutionary biologists to use the H-W model, which is based on a set of assumptions that are generally false? Null hypothesis- bases that we use to compare the changes in evolution that are being made 22. As far as we know, natural selection cannot adapt organisms to future changes in the selective regime. Yet, many organisms exhibit responses in advance of natural events. For example, geese migrate south from the summer breeding grounds long before the weather changes. How can these "anticipatory" behaviors have evolved? To increase its fitness 23. What do you expect will happen to means and variances of phenotypes in a population subject to the following kinds of selection? Be sure to be able to show diagrammatically how the distribution of normally distributed trait will change after being subjected to each of these kinds of selection. Give examples of each. a) Stabilizing selection Preserves average phenotype b) Disruptive, or diversifying, selection Preserves variation, little effect on mean, basically favors individuals that are above and below the average c) Directional selection Favors individuals that are either above or below the average d) Heterosis Heterozygote advantage, the ones that have BOTH the dominant and recessive traits have an advantage describes the increased strength of different characteristics in hybrids ; the possibility to obtain a genetically superior individual by combining the virtues of the parents + Eg. Warfrain resistant rats e) Frequency-dependent selection 1. 2. l33 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Fitness varies on the frequencies The higher the frequency, the lower the fitness 24. Which of the following is most likely to occur in populations that are reduced to a very small number of breeding individuals? Choose one answer from each pair: a) Variation in genotypes and phenotypes is likely to increase, relative to the amount of variation in the original population, OR b) Variation in genotypes and phenotypes is likely to decrease, relative to the amount of variation in the original population. a) Genotypes and phenotypes are likely to occur at the same frequencies as they did in the original populations, OR b) Genotypes and phenotypes are likely to occur at different frequencies than in the original population. a) The probability of extinction would probably be similar for the reduced population than for a similar population with large numbers of breeding individuals, OR b) The probability of extinction over a specified period of time (say 104 years) would probably be higher for the reduced population compared to a population with many breeding individuals. 25. Many textbooks imply that the reason Irish elk, in which males had enormous antlers (spanning nearly 3 m), became extinct is that the males simply could no longer haul around such large ornaments without collapsing. What is the flaw in this argument? I think before we start thinking about sexual selection, we should take into account what happens to deer and elk every season. I think the flaw in this argue is that elk lose their antlers every year, so it is not like they have to keep hauling around large ornaments for longer than one year. Females may be attracted to elk that tend to grow bigger antlers in a shorter time period, but elk do not keep their antlers for their entire life. ^Yeah that’s an excellent point Is this because the males could attract mates with their antlers and continue to reproduce? Or is it because the antlers kept them from reproducing? Isn’t this talking about intersexual selection, when females choose males based on their traits. In this example, they’d choose the males with the biggest antlers. This is similar to Couldn’t a flaw in this argument be that plenty elk populations lived to reproduce for years before they were extinct, and if they couldn’t handle the weight of the antlers, they could have had adaptations or evolution working towards helping them handle the weight of those antlers ^That’s along the lines of what I was thinking… that if the elk truly could not support the weight, then natural selection would act and favor those elk with smaller antlers, eventually reducing the mean antler size (or they would develop mechanisms to support the weight). 1. 2. l34 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - ^ I agree. The frequency of smaller-antlered elk would have increased in the population. I think the only way that they would go extinct is if there was somehow 0 genetic variation in the population. 26. What is the basic difference between intersexual and intrasexual selection? Give examples of each mode. Can you imagine an example in which both modes of sexual selection operate? Intersexual: selection favoring traits in one sex that attract the other (ex: peacock colors) Intrasexual: selection of a mate through competition (usually males, ex: male lions) 27. [If we get to kin selection] The ability to recognize kin may promote the evolution of altruistic traits. What is the evolutionary rationale for this argument? If altruism reduces an individual’s fitness, natural selection should select against it rb-c>0 28. [If we get to kin selection] Explain the rationale for the evolution of sterile female workers in social Hymenoptera? Can you use the same reasoning to explain why young acorn woodpeckers often help their parents rear offspring, rather than reproduce themselves? Can you use the same reasoning to explain the human demographic transition? The rationale for the evolution of sterile workers is that the role of the sterile workers is to help their kin/queen. This increases the fertile individual’s fitness but it also indirectly helps sterile worker’s fitness because they share genes with the fertile relative who will reproduce and pass down these genes. Because of haplo-diploid sex determination in Hymenopteran insects, females are related to their own offspring by the usual 0.5, but to their full sisters by 0.75. So, it may be more profitable in terms of inclusive fitness to help your mother rear more of your sisters than to have your own offspring. A young acorn woodpecker has, on its own, essentially no prospects of rearing its own offspring until it owns its own territory. That usually won't happen for a few years, at best. So, while it's waiting for a good territory to become available, it might as well help other family members rear offspring on their territory. And, going back to the human demographic transition, it's not at all clear that kin selection can help explain why humans voluntarily reduce their own reproductive output, because they usually do not do it to directly benefit close relatives. LECTURE 17- 18 QUESTIONS 1.What is the competitive exclusion principle? What general condition must be met for two potential competitors to avoid competitive exclusion (i.e. to coexist)? When 2 species that use the same resource in the same way can’t coexist. One will drive the other to extinction. -if they do coexist, they must share resources and they must differ in the way they use their resources, (lizards eat different parts of a tree) - they must segregate in space and time (Resource Partitioning). 1. 2. l35 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 2. What is ecological character displacement and explain how it can result in low niche overlap between similar competing species? Character displacement is the process of evolution toward niche divergence as a result of interspecific competition. Ecological character displacement is when two species living in the same area narrow their niches to specialize for a certain resource and decrease competition. It can result in low niche overlap by directionally selecting for traits in species that do not create competition with different species. (Ex. When two different species of finches are isolated, both show an average beak size of 6 inches. When both of the finches live in the same area and compete for resources, populations on one finch species increases frequency of small beaks and the populations of the other finch species increases frequency of large beaks, while the average size beak finches die off due to high competition for resources. 3. What is the difference between the fundamental and realized niche? Fundamental: defined by physical conditions under which a species can persist Realized: species actually occur over a narrower range of nutrients due to competition from other species 4. Describe how tradeoffs can allow species to coexist even if they use the same resources and one is a vastly superior competitor to the other. Offer a plausible example (there are many possible examples if you look back at your notes from lectures on tradeoffs). Trade offs could allow species to coexist, using the same resources, even if one species is vastly superior competitor to the other since the inferior species could have a larger realized niche as compared to the superior competitor. for example in the barnacles that live in tidal zones. There is one species of barnacle that is a superior competitor compared to the other barnacle, but the inferior barnacle has higher stress tolerance. The trade off that allows these two species of barnacles to coexist is the stress tolerant barnacle only lives in the high stress area where the superior competitor could not survive, even though it could in theory live in both high stress and low stress tidal zones. The superior competitor only lives in the low stress tidal zone, where it outcompetes the inferior barnacle, since it could not survive in the high stress tidal zone. 5. The following graph depicts the performance of 3 bird species (green, red, blue) as a function of prey size. The sizes of prey that can be consumed by each species are a function of the bill size, which is under genetic control. A. Which pair of species have the highest competitive overlap? REd and green B. Which pair of species have the least competitive overlap? Green and blue C. Draw curve depicting the niche of a species that would coexist with all 3 of these species 1. 2. l36 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Type 2:As the prey population increases in density, number of prey consumed initially increases rapidly but quickly levels off as the predators reach satiation.This type of functional response leads to a leveling effect on the populations and results in stable cyclic relationships, although other logistic factors must be considered. D. Draw curve depicting the niche of a species that would coexist with ONLY the blue species (it would be excluded by either red or green) Type 3:As the prey population increases in density, the number of prey consumed accelerates initially (with consideration of learning time and prey switching), reaches a period of linear growth, then begins to decelerate as the predator species reaches satiation. This type of functional response leads to logistic relationships between predators and prey. (CC) *low efficiency at low density due to prey switching or refuges. E. Draw a curve depicting the niche of a species that might cause the niche of the blue species to evolve in such a way that it would compete more with the red species than it does now. Directional: put on the right so it moves to the left F. Part F refers to the graph above. Choose among the following possible answers: stabilizing selection, disruptive selection, or directional selection. a. The green species would exert what kind of selection on the red species? Directional b. The green and blue species together would exert what kind of selection on the red species prey size Performance Stabilizing c. Draw the niche of a species that would exert disruptive selection on one of the other species shown on the graph. Overlapping on the mean of one of the colors (would correlate to an overlap in the resources used by both species) d. For one of the above examples (5F, part a, b or c), draw graphs of the type of data you would need to convince yourself that all three conditions for natural selection to occur could be met in the example. Be sure to label the axes on your graphs. You may draw a separate graph for each condition or use the same graph for multiple conditions, as appropriate. Three conditions: heritability, variation, and differential mortality Three different types of graphs 6. Explain the difference between exploitative and interference competition and give an example of each. Exploitative: resource depletion, basically what one individual can use, another cannot. They don’t need to encounter each other to compete with each other - This is for food - A person in the front of the food line vs the person in the back of a food line2 1. 2. l37 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Interference: this is when confrontation between the competitors happen and prohibits others from using resources - Example of this is for space 7. In the lynx-hare example we discussed in class, explain how changes in predator abundance over time is both a cause and a consequence of the abundance of prey. You need not be able to reproduce the equations, but you should be able to take a graph of predator and prey abundance and explain carefully what causes each population to go up or down in size over time. As prey increases so will the predators, if prey decreases it is followed by a decrease in predators + More lynx -> less hare + More hare -> more lynx Side note: Prey has 2 kinds of Density Dependent methods of mortality 1. Intraspecific Competition for resources 2. Density Dependent mortality caused by the predators 8. How does intraspecific competition contribute to stabilization of predator-prey cycles? Or, put another way, how could intraspecific competition actually PREVENT a prey species from going extinct? Competition causes the population to be try to constantly get better and keep them in check. If there was no competition then the population would just use all the resources quickly and the population would over grow, but once the resources are all used the population will go extinct. + Relates to the notion of variable fitness (not everyone will survive, can be based on morphological differences) - Only the ones most fit will survive -- for definitions sake: INTRASPECIFIC COMPETITION: members of the same species compete for the same resources. This leads to reduction of fitness for both individuals. INTERSPECIFIC competition: members of different species compete for a shared resource. 9. What is a functional response? Explain what biological processes or phenomena would cause each type of functional response. and what three main shapes can they take? What are the three types of functional responses? Compare how changing from a type I to a type III functional response affects the oscillations of predator and prey populations? - How the number of prey consumed per predator changes with prey density. 1. 2. l38 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - - The functional response is how the number of prey consumed per predator changes with prey density; we have a linear functional response: number of prey consumed per predator is an increasing function of prey density; functional response can also appear - sigmoidal or logistic in its graphical curve Linear: Type 1 Curve Exhibits exponential increase in prey consumed by predator. An increasing function of prey density. Logistic: Type 2 Curve number of prey eaten per predator increases to a capacity where which the predator is satiated; the predators hit the limit at which they can reproduce and the number of prey eaten per predator evens out + Almost like getting full from a buffet, only so much you can actually eat Sigmoidal: Type 3 Curve predators under-consume prey at very low densities due to refugees or prey switching (limited prey), when prey is more abundant, the number or prey eaten per+predator increases rapidly then levels out at a capacity where the predator is satiated 10.Consider the example in lecture of evolution of algae in response to predation by rotifers in the laboratory. What kind of selection do you think is in operation here? What data would you need to convince yourself that the pattern depicted in the example is indeed the product of natural selection? HINT: Think about the conditions that must be met for natural selection to occur and then state either in words or with a graph what evidence would convince you that the condition was met in the population of algae. Directional - When predators are abundant, resistant genotypes are favored, but these have lower reproductive rate. Poor food reduces predator populations. When predators are few, resistant genotypes have no advantage, and susceptible genotypes have the advantage (greater reproductive rate). Nonresistant algae dominate the population, which leads to increased predator population size. Evolution in prey population is causing changes in K for both predator and prey. There is a tradeoff between predator resistance and competitive ability/reproductive rate. LECTURE 19-21 QUESTIONS 1. What is the biological species concept, and what are its main criteria for defining a species? 1. 2. l39 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - A species consists of groups of actually, or potentially, interbreeding natural populations of organisms that are reproductively isolated from other such groups. Species represent separate evolutionary units that can no longer exchange genes, hence evolve independently of each other. (Reproductive isolation) + KEY, Must be Reproductively Isolated! Also remember “Two individuals are members of DIFFERENT species if they DO NOT produce viable AND fertile offspring in nature” So even though two species can reproduce, doesn’t mean they usually would 2. Explain why application of the biological species concept is difficult or impossible in each of the following situations: (a) examples of natural hybridization, (b) the existence of strictly asexual organisms, and (c) disjunct (allopatric) distributions of species. (a) examples of natural hybridization: grey wolves/red wolves – rare but can still reproduce naturally (b) the existence of strictly asexual organisms, because that’s not really reproduction – it’s just division (c) disjunct (allopatric) distributions of species – the species live geographically far away and do not exchange genes freely in nature 3. Two closely related grasshopper species occur sympatrically. No hybrids have been reported in nature. However, when an evolutionary biologist brings the two species into the lab, she discovers that they can hybridize to produce fertile offspring. How can you explain these observations? Should the grasshoppers be considered separate species? They are considered different species since they do not produce viable and fertile offspring in the wild – they do not freely exchange genes in the wild. If humans must intervene, it is not a biological species. Their reproduction is not natural 4. How does natural selection versus genetic drift act to promote the evolution of intrinsic barriers to gene exchange in allopatric (both vicariance and peripatric/dispersal modes) versus parapatric versus sympatric models of speciation? Natural selection exposes the population to intrinsic barriers (pre and post zygotic). In peripatric speciation genetic drift plays a very large role because speciation is generally driven by founder effects. Because of the small size of these founders, drift enhances the rate at which species 1. 2. l40 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - can diverge, though selection is still obviously important. In vicariance, parapatric, and sympatric speciation, drift plays less of a role and diversifying selection is the main cause. Natural selection - 1. individuals vary with respect to phenotype 2. phenotypic variation is heritable 3. phenotypic variation results in differential reproduction Genetic drift - variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce. Allopatric- occurring in separate non-overlapping geographic areas (speciation due to geographic isolation) Vicariance- A physical barrier subdivides a species range into 2 or more populations that no longer freely exchange genes. Once it has occured, the separated population can independently accumulate genetic differences through diversifying selection and/or genetic drift. Once gene flow is interrupted between 2 populations, environmental differences that create either pre or post zygotic incompatibility. Most of the reproductive isolations happens when the populations are allopatric. Speciation is a byproduct of the divergent selection that occurs during allopatry. Peripatric - related to founder effect where a new species is formed from an isolated peripheral population. May be driven by genetic drift (in small, newly founded populations) with diversifying selection. Parapatric- parapatric populations have adjacent but non-overlapping borders so there are no obvious extrinsic barriers. If dramatic discontinuities match distributions of 2 populations then reproductive isolations evolves. Migrants from one population to the other will be selected against. Sympatric - have completely overlapping physical ranges/ exist in the same environment Note: Allopatric Speciation = GeogrAphic Isolation Parapatric Speciation = Temporal Isolation (no physical/extrinsic barrier) 1. 2. l41 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 5. Why have island archipelagos played such an important role in the development of the science of speciation? What lessons have we learned from studies of speciation in places like the Hawaiian Islands? These islands are clear forms of geographic isolation. Because they are so close to each other we are able to see and understand why species are related yet far enough apart that the original species they originated from. You can see how the new species had to evolve to its specific island. + The method of speciation that would take place in the two populations = “Allopatric Speciation” + Allopatric speciation correlates with physical/extrinsic barriers, preventing gene flow to take place 6. Why do most evolutionary biologists agree that allopatric speciation is common but sympatric speciation is not? Focus your discussion on the fundamental difference between these two alternatives, and why that difference is likely to be important for divergence and the evolution of reproductive isolation. Allopatric speciation is much more common and obvious because there are clear extrinsic barriers to gene flow that are obvious to see. In sympatric speciation it is much more subtle and there needs to be microhabitats within the overlapping habitat. Without microhabitats, it is impossible for different subpopulations to have different traits to be selected for and speciation would never occur. 7. Sympatric speciation is generally thought to be a rare event because sympatry should promote gene flow. Explain clearly the evidence that speciation occurred sympatrically in the crater lake cichlid fish inhabiting Barombi Mbo in Cameroon. In particular, explain how the phylogenetic relationships of the 11 species of cichlids in this lake support the argument for sympatric speciation. How does this contrast with the phylogenetic evidence for vicariant allopatric speciation in snapping shrimp? Be sure that you can look at a phylogenetic tree and understand whether its structure is consistent with sympatric versus allopatric scenarios for the evolution of reproductive isolation. Speciation among the crater lake cichlid fish happened because the 11 species diverged in sympatry (overlap). Based on the phylogeny, the 11 species are monophyletic. The mechanism used was multiple niche polymorphism- genetic variants in population consume different prey that select for different traits. This subdivides the pop, selecting against mates that don’t specialize on what they specifically eat. Results in genetic differences and reproductive isolation. Very high dispersal potential. There was a physical barrier to divide a species into two or more populations for snapping shrimp, where they can’t freely exchange genes. Isthmus of Panama shut off gene flow between 1. 2. l42 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - the Pacific Ocean and Caribbean Sea (vi cariant event). Seven sister species in the shrimp resulted on opposite sides of barrier. 8. Compare and contrast, using a phylogeny from lecture or the book, the differences between monophyletic, paraphyletic, and polyphyletic clades/taxa. Why are Reptilia without birds (Aves) paraphyletic? Why do evolutionary biologists aim to name only monophyletic taxa? Why are non-monophyletic taxa a problem? Do sister species represent a monophyletic taxon? Monophyletic- taxonomic group that INCLUDES ALL of the species descended from a specific common ancestor. Paraphyletic- a taxonomic group that excludes some of the descendants from a specific common ancestor. Polyphyletic- a taxonomic group that does not contain the most recent common ancestor of its members. Reptilia without birds is paraphyletic because birds is a descendant just like the other members of reptilia and they are all descended from the same common ancestor but one of the descendants (birds) is being excluded from this common ancestor. Monophyletic is good because it includes all of the species that descended from a single ancestor and non-monophyletic are a problem because it excludes some of the descendants from the common ancestor. Depending on interpretation of monophyletic it could also be excluding extinct species. Sister species represent a monophyletic taxon. (crater-lake cichlids) 9. An island in an isolated oceanic archipelago of recently formed (the last few million years) volcanic islands is colonized by three mainland species of beetle. The three species differ in several important characteristics (see table on the next page). What do you predict will be the patterns of diversification and speciation for the three descendant lineages? Explain how the 1. 2. l43 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - differences in dispersal potential, feeding ecology, population size, and mating behaviors affect the potential for speciation in each of the three species. - Not a lot of ecological specialization, on what they’re feeding or mating with. Gene flow is abundant. Meaning likelihood to diverge is low. - Since they’re non specialist = low chance of speciation - Regarding the ability for flight, a high dispersal ability would be prevent speciation because it increases the potential for gene flow. Having a small, patchy population size would increase likelihood for speciation because genetic drift is inversely proportional to population size (a smaller population is more affected by genetic drift). Intraspecific variation for host preferences increases the potential for speciation because individuals will mate and feed on specific host plants and therefore the chances of interbreeding between the organisms on these host plants will decrease. Therefore, Species 3 is the most likely to speciate. 10. With respect to the phylogeny shown below, which of the following statements is TRUE : a) Species F, G, H, I, and J form a polyphyletic group. b) Species A, B, C, D, and E form a paraphyletic group. c) Species A, B, I and J form a monophyletic group. d) Species F, G, and H form a monophyletic group derived from the same common ancestor. e) Species C, D, and E form a monophyletic group. 11. In the phylogeny shown below, what is the fewest number of speciation events that could have given rise to the clade that includes species A, B, C, D, and E? a) 4 b) 6 c) 8 d) 3 e) 11 1. 2. l44 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - f 12. In apple maggot flies, Rhagoletis pomonella , adults and larvae feed on very specific host plants. There are at least three genetically distinct lineages, one of which specializes on hawthorn trees, another specializes on apples, and the third specializes on cherries. They are pretty good fliers, easily capable of moving several kilometers a day. They can also mate with each other, and the hybrids are fertile. In the example shown below, there are only apple or hawthorn trees available for the maggot flies. Assume that apple specialists feed and mate primarily on apples, and that hawthorn specialists feed and mate primarily on hawthorn fruits. (Sometimes, though, if it were available , an apple specialist might feed on a hawthorn, and a hawthorn specialist might feed on an apple.) Adult flies emerge a few weeks before their preferred fruit matures, fly around for awhile, then lay eggs on their preferred host (where their larvae feed and develop). What are the main barriers to gene flow between these two races? What, if any, is the importance of timing of fruit maturation in this scenario? How would you expect changes in timing of fruit maturation to affect the likelihood that hybrids would be formed? Assume that the apple and hawthorn races were good biological species. How could you distinguish whether they speciated sympatrically or allopatrically? 1. 2. l45 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - o Allopatric speciation : a result of populations of a species becoming isolated from each other. § Caused by geographic separation: mountain ranges, rivers, glaciers or canyons § Stages · 1. Moving into new environment - a single population in a relatively homogenous and competitive environment will move into new region will have a regular gene flow · 2. Geographical isolation - isolation of parts may occur due to physical barriers - ex: rise and fall of the sea level · 3. Different selection pressure - isolated populations may be subjected to different selection pressures, favoring individuals with traits that suit each particular environment - subspecies which has significantly different genes from parents population will emerge · 4. Reproductive isolation - separated population undergoes changes in their genetic makeup and behavior patterns - gene flow does not occur o Sympatric speciation § Niche isolation: when a population exists within a diverse collection of microhabitats; some organisms prefer to occupy one particular type and rarely interact with fellow organisms that prefer other microhabitats § Polyploidy: occu Temporal Isolation rs during meiosis when cells divide incorrectly and produce gametes that are diploid Dont Forget ! 13. Why do most evolutionary biologists agree that allopatric speciation is common, but sympatric speciation is rarer? a) Because reproductive isolation CANNOT evolve in sympatry. b) Because sympatric species cannot occupy separate niches. c) Because there is no extrinsic barrier to gene flow in sympatry. d) Because inbreeding is too common in sympatry and populations go extinct. 1. 2. l46 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - e) Because disruptive selection can only act on allopatric populations. - Allopatric speciation:there is a physical barrier that subdivides a species range into 2 or more populations that species can no longer freely exchange genes. It is much more common because there are clear extrinsic barriers to gene flow. Things like geographical or spatial barriers make gene flow restricted, and thus is more common to see populations diverge. Events that divide a species range are called VICARIANT events.Once vicariance has occurred, the separated populations can independently accumulate genetic differences either through (1) diversifying selection or (2) genetic drift (or both). Since there is a physical barrier, there is not going to be any selection to avoid mating because there is no opportunity to mate with other species. -In sympatric speciation however it is more subtle, and there needs to be microhabitats within the overlapping habitat. There is no obvious geographic barrier to gene flow. For there to be divergence, there would have to be essentially no gene flow between microhabitats.This could happen if a species had very little dispersal potential, or a species exhibited very strong preferences to mate with like phenotypes(positive assortative mating).In sympatric speciation, species have overlapping ranges (so it is possible for them to interact and therefore exchange genes). Sympatry should promote gene flow since there is overlap. Have the opportunity to mate with others and selection should favor the evolution of prezygotic isolation mechanisms. Sympatric species have much higher levels of prezygotic isolation than allopatric. This suggests that Reinforcement when populations become sympatric, shifts from POSTzygotic to PREzygotic. 14. The main problem with understanding how genes responsible for reproductive isolation could increase in frequency is... a) such genes would reduce the fitness of an individual that carries them. b) such genes would rapidly spread due to sexual selection. c) genetic drift would immediately eliminate them from a population. d) hybrids carrying these genes would be competitively superior to parental genotypes. e) none of the above. - My reasoning is that the genes responsible for reproductive isolation decreases fitness because it decreases number of possibilities of the number of offspring produces. Limits options and thus limits fitness. 15. You carefully study adjacent populations of two very similar meadow mice, one from Woodland (about 15 km north of Davis), the other from Davis. You want to know whether the Woodland and Davis populations belong to the same biological species or to two different species. You could most confidently decide this if you could... a) show that where the ranges of the two mice overlap there is no hybridization. b) bring the two types of mice into the laboratory to see if they will mate. c) demonstrate that the natural ranges of the two types of mice are entirely allopatric. 1. 2. l47 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - d) show that there are statistically significant coat color differences between the two types. e) show that the Woodland mice prefer to eat meat, but the Davis mice prefer to eat tofu. 16. Two species of wild lettuce grow sympatrically, but one flowers in the early spring, and the other flowers in the summer. This is an example of... a) post-zygotic reproductive isolation b) gametic incompatibility c) behavioral isolation d) temporal isolation e) reinforcement f) hybrid incompatibility 17. In Australia, when red-bellied black snakes first encountered cane toads, most of the snakes were highly susceptible to the cane toad toxin, and died soon after eating them. The graph shown below compares susceptibility to toad toxin of individual snakes, from two populations, one never exposed to cane toads (TOAD NAÏVE), the other having been exposed to cane toads for 50 years (TOAD EXPOSED). Each point on the graph represents data for a single snake. You suspect that natural selection has caused the changes shown in the graph. We know that snakes reproduce, meeting the first condition for evolution by natural selection to occur. What are the additional 3 key conditions that must be met in the snake population in order for natural selection to have occurred? Based on the information in this graph, is there evidence that each of these conditions is met? If so, how is each met? If not, what kind of evidence would convince you? 1. 2. l48 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Condition 1: Is condition #1 demonstrated by data in the graph? If yes, how? If not, then what data would convince you? Phenotypic Variance: Individuals within a population must vary phenotypically (variance) DATA: Varying levels of susceptibility to toxin is seen in the graph given Condition 2: Is condition #2 demonstrated by data in the graph? If yes, how? If not, then what data would convince you? Heritability: Individuals pass on at least some of their traits to their offsprings (inheritance/heritability) DATA: Not much direct evidence from graph given; need a graph depicting parent-offspring ratios of the snakes Condition 3: Is condition #3 demonstrated by data in the graph? If yes, how? If not, then what data would convince you? Phenotypic variation leads to differences in survival/reproduction DATA: Need a graph that depicts the survival rates of toad-naive and toad-exposed snake populations LECTURE 22-25 QUESTIONS 1. Define the following terms: mutualism, commensalisms, positive interactions. Mutualism: both species benefit ● Obligate mutualism : mutually beneficial interaction between 2 species in which each species REQUIRES the other to persist (obligatory) ● Facultative mutualism: benefits both parties, but NOT required for either to persist Commensalisms: an association between organisms in which one benefits and the other derives neither benefit nor harm Positive Interactions: at least one species benefits, neither is harmed; one species that is resistant to a “stress” locally reduces that biotic or abiotic stress, benefiting species that are susceptible to that stress 2. Explain why positive interactions play a prominent role under “stressful” conditions. Draw a graph depicting how the strength of positive interactions changes along some environmental stress gradient (predation pressure, physical stress, etc). 1. 2. l49 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Positive interactions can expand realized niches for species when they’re under stressful conditions (water, nutrients, predators, competitors, etc). For example, mycorrhizae fungi help plants grow by fixing N for its use. Without the fungi, plants would be more limited to areas already plentiful in nitrogen levels 3. A. Distinguish between the fundamental and realized niche. B. Draw a hypothetical fundamental niche for a species of your choice. C. use this diagram to depict how niche shrinking and niche expanding factors can modify the fundamental niche to produce the realized niche. 4. U sing a specific example of an interspecific interaction from lecture, describe how the same two species can interact to produce a range of outcomes, from positive (facilitative) to negative (competitive or consumptive). B. What components of the physical or biotic environment must change to cause this switch? Mycorrhizal fungi with plants - based on nutrient availability and water, the fungi's effect on the plant can range from mutualism (at low nutrient/water in soil) to commensalism (medium nutrient/water - fungus benefits while plant doesn't really need the fungus anymore) to parasitism (at high nutrients/water, fungus steals plant's carbon, while plant definitely does not need the fungus anymore). B. What components of the physical or biotic environment must change to cause this switch? 1. 2. l50 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Because positive interactions involve two species where one is resistant to a stress locally reduces that biotic or abiotic stress then it benefits species that are susceptible to that stress. Thus to make the transition, the species that is susceptible to the stress must evolve to resist the stress or the resistant species is adding to the stress of the environment. The stress could also be removed. Or maybe the amount of nutrients present in the environment causes a change. 5. Compare and contrast what drives cycles of measles outbreaks (or other infectious diseases) compared to cycles of predator-prey as in the lynx-hare example from lecture. I think this is comparing it to the cycles of predator-prey because the outbreaks also fluctuate and have cycles. Contact between infected and susceptible individuals causes the density of individuals that are infected to increase. When I is increasing, it means there is an “outbreak” of the disease occurring. I increases if BSI> dI (probability of transmission x density of individuals that are susceptible to the disease x infected > recovery rate x infected).When the number of individuals susceptible is greater than d/B, the disease has reached threshold density to spread. When S drops, the outbreak dies out bc there are not enough susceptible indiv. and reproductive rate of the pathogen becomes less than 1 (cycle drops). S will increase again due to immigration/emigration which allows outbreak to happen again. ( and the cycle continues) cycles of predator-prey: resource abundance influences population density, hare populations increase when predator populations are low and resources are high, predators take advantage of this and become high, when prey populations decrease because there is a lot of predators, the predator population will also decline. So basically, disease outbreaks are driven by the amount of susceptible and infected organisms while predator-prey cycles are driven by the amount of resource available and the rate of predation. 7. How does vaccination reduce disease frequency and how can small decreases in the number of people being vaccinated lead to large changes in the extent of outbreaks of the disease? If enough people have had the disease then it keeps S (number of individuals susceptible) below the threshold density which makes it hard for the disease to spread. Vaccinations expose people to a dead form of the virus so their body can recognize it and fight it the next time it becomes a threat. If less people get vaccinations, then less people are protected which leads to a greater chance that there will be more outbreaks. 8. Offer 2 possible ways to reduce disease spread that both involve decreasing the number of susceptible organisms in the population. Immunization, culling the herd (keeping the population in check so that the disease does not spread (no new susceptible individuals introduced to the population)), (herd immunity) 1. 2. l51 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 9. Why might natural selection favor variants of a disease that are LESS virulent? Describe one example of this phenomenon. Natural selection might favor variants of a disease that are less virulent because the virus just need host to live long enough until they can transfer the disease. When the population falls, there are less chances of coming in contact with another member so it is more beneficial to become less lethal so the host will live long enough to spread. The virus doesn’t consciously try to not kill the host- it is just that if a virus is very lethal and kills the host before it is passed on then that virus has really low fitness. The weaker strains would have a higher fitness because they were able to spread. 10. Define and give an example of the following terms: keystone species, foundation species, trophic cascade. Draw a real food web (one from lecture or someplace else) that depicts each of these. Keystone species- a species on which other species,despite being low in abundance, in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically. (the otters in class example) Foundation species- Keystone species do not form the ecosystem but keep it going. Whereas a foundation species abundance provides the foundation of a habitat (coral, trees, algae ) Trophic cascade- powerful indirect interactions that can control entire ecosystems, occurring when predators in a food web suppress the abundance or alter the behavior of their prey, thereby releasing the next lower trophic level from predation (or herbivory if the intermediate trophic level is a herbivore). Sea otter (keystone species) → urchin → kelp (foundation species) 11. You are an environmental consultant hired by a town adjacent to a small lake in the Sierras. The figure below describes what you know about the food web of the lake. The town is economically depressed, and residents have proposed two ideas for stimulating the local economy (1) introduce northern Pike (a fish that only eats other fish) into the system to attract sports fishermen (and their money) to the area and (2) harvest filter feeding bivalves from the lake for food (they are quite a delicacy and fetch a hefty price). The town wants you to predict for them the consequences of each proposal for the health of their lake, long renowned for its crystal clear waters. 1. 2. l52 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Proposal 1: Pike eats the planktivorous fish so there will be less of those in the lake. Since there is less planktivorous fish, there will be more herbivorous crustaceans and in turn, there will be less algae since the herbivorous crustaceans eat algae along with the bivalves. Less algae means there will be less dead organic matter in the lake, retaining its clarity. This way, the fishermen will fish the pike from the lake and the lake will be kept clear. Proposal 2: Harvesting filter-feeding bivalves would mean there is less competition for the herbivorous crustaceans in feeding on algae. However, because of the fact that there are still planktivorous fish feeding on the crustaceans, the algae wouldn’t be driven to deforestation (for lack of better word). There would not be mucdh of a disturbance in the rest of the ecosystem, and the bivalves would allow the town to gain a lot of profit from selling it. p 12. A. Name and describe the three "models" or “mechanisms” of succession. B. Be able to relate an example of succession in a real community and explain how successional change in that community is determined by one or more of these mechanisms. Succession : Pattern of changes in the species composition as a result of colonization and the species interactions after a disturbance (r selected species and k selected species) 1. Facilitation : an organism modifies the environment in a way that makes it better and allows other species to exist. Specific pioneer species are necessary to modify the environment so that later species can colonize 2. Inhibition : when pioneer species inhibits subsequent colonization of habitat by making environment less suitable for subsequent colonization 3. Tolerance (neutral) : Pioneer species neither make it better nor worse for subsequent species to colonize. 1. 2. l53 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 13. What are the characteristics of typical early successional species and late successional species? 14. For your graduate research you have chosen to study the recolonization of disturbed communities of sessile marine invertebrates like those you studied in lab. From observing a time series of plastic panels that have been submerged for varying lengths of time you observe that panels deployed for short periods of time are dominated by colonial sea squirts, whereas those left out for longer periods of time are dominated by solitary sea squirts. Describe an experiment you could perform to test whether the facilitation, inhibition or tolerance model of succession is operating. Draw a graph of your expected experimental results for each model of succession. If we remove the colonial sea squirts we can detect if it takes longer for the solitary sea squirts to show up. If it does then facilitative model was happening. If the solitary show up faster than normal, then the inhibition model was happening. If there’s no change then the neutral/tolerance model was happening. 15. Explain how fishing can exert selection on size at maturity. What type of selection is this? What is the observed evolutionary response in fish? How might this slow down recovery of fish stocks, even if fishing is stopped altogether? Larger, more mature fish are being killed so the smaller fish who mature early have higher fitness. This leads to a greater number of small fish. there is a directional selection for smaller sized fishes. The evolutionary explanation will be: the fact that directional selection leads to a greater abundance of smaller fish, it eliminates one of the four conditions: variation. It’s hard for the population to recover b/c only small fishes are left and two small fish can’t have big offsprings. Also the number of offsprings that one fish can have is positively related to its body size. a 16. Describe the intermediate disturbance hypothesis (IDH) and use this hypothesis to predict how diversity will change throughout the course of succession. 1. 2. l54 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - The IDH states that organisms with intermediate disturbances to their habitats will have higher diversity than at either extreme level of diversity. At low disturbances, there is competitive exclusion so there is low diversity. At high disturbances, there is disturbance-caused extinctions, which is likely why r species can survive better there. In early succession, r species will dominate because they can tolerate high disturbance but in late succession, species that can tolerate intermediate disturbance like K species will prosper because the disturbance promotes coexistence between species. (Disturbance in general is defined here as any process that removes biomass from the community) 17. A. What is ecological efficiency? Refers to production at level n/production at level n-1. In other words, it is similar to the total amount of energy obtained from consumption. This is explained more in the lecture slide with the flow chart showing trophic transfer (the movement of energy up a food chain). The production available for consumption (from plants for example) goes through a long process. A percentage of it is not consumed and is converted to dead organic matter, while the other percentage gets ingested. A portion of that cannot be digested so it is excreted. The remaining portion is assimilated. What is left for available use goes towards production (growth, reproduction etc.) or to respiration (i.e. maintenance). On average only about 10% of the energy is actually used once it goes through this long process. Only a small fraction of production at one level is actually converted to production at the next. B. Give an average value of ecological efficiency for most ecosystems. It ranges from 1-25% but on average, it is 10% C. Explain how ecological efficiency can place an upper limit on the number of trophic levels in an ecosystem. The limit to the number of trophic levels in a system is set by the available energy (produced by primary producers) but also the efficiency of energy transfer among links in the chain (taken from lecture slide). Each added trophic level there is, energy is lost because of all the transfers. Most organisms spend most of their gained (assimilated) energy on maintaining body temperature so the energy they obtain is allocated to mostly that. only a small fraction can be used for production efficiency. 18. Not all the production at one trophic level makes it to the next. Explain the fate of energy from producer to consumer, including where energy is lost. Explain how and why the relative size of these sinks (=loss of energy) might change as a function of (1) consumer trophic level and (2) mode of thermoregulation (endotherm vs. ectotherm). A lot of energy is excreted because it cannot be digested, or is used for respiration rather than production at trophic level n. If there are less trophic levels (consumers in it i.e. secondary, tertiary) more energy is able to transfer to the lower level consumer. It’s because carnivores (and higher trophic level animals) spend a lot more energy on respiration because it’s much 1. 2. l55 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - harder for them to catch prey (ex. a cheetah to run and catch its prey) than an herbivore (a cow can just eats grass and not move) SO bigger trophic level= more energy loss through respiration bc harder to get food. Endotherms spend most assimilated energy on maintaining body temperature (most energy is used for respiration/ assimilation). Ectotherms, however, are able to use energy on production efficiency ( growth, reproduction etc.) 19. A. Name two factors that determine the maximum number of trophic levels in an ecosystem. primary production ecological efficiency including metabolic demands (endo vs ecto) B. For an equivalent change in magnitude, which of these two has a stronger effect on the amount of energy available to top consumers? Explain your answer. ecological efficiency has stronger effect if the efficiency of trophic level to trophic level is low, the primary production energy will dissipate very fast, doesn’t matter if there’s high primary production or low primary production energy if the efficiency of trophic level to trophic level is high, more production will be carried to more trophic levels and more trophic levels will be supported. primary production matters, but the efficiency species have to transfer this energy depends on how efficient they are 20. What one factor typically MOST limits primary production in the following environments: A.open ocean B. terrestrial forest? Why? For (A), I think that it is nitrogen. In one of the lecture slides for Lec. 22, it says, "in the ocean, it's more the addition of nitrogen that causes algal blooms." As Prof. Stachowicz told us, the ocean is full of algae (the primary producers in the ocean). So, if you have a lot of nitrogen (nutrient pollution), you have algal blooms. As a result, you'd want less nitrogen to prevent algal blooms given that they are harmful (the algae eventually die, fall to bottom of lake & decompose, consume all O2 and everything in the food web dies). So with that, I believe that nitrogen would be the limiting factor for primary production in the open ocean. For (B), I think it is rainfall. We know that the terrestrial forests are the site of high primary production, and many of them are located around the equator. The equator has the most rainfall. So if you did not have a lot of water, then the primary production in those forests would be limited/reduced. And vice versa. I believe the terrestrial forest has water as its limiting factor and the ocean has nutrients as their the limiting factor. The ocean really needs the nutrients from the “bottoms up effect” (coastlines). The forests need water and they receive this through precipitation. 21. Explain how each of the following factors affect local species diversity. Provide an example to illustrate your answer. A. Environmental variability 1. 2. l56 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - A fluctuating environment over time can promote diversity since temporal fluctuations in environmental conditions prevent competitive exclusion by altering the competitive hierarchy. B. Foundation species They have a high biomass and habitat forming characteristics which allows for other species to use them for refuge. C. Productivity (resource availability) More resources does not mean more species. Resource diversity rather than quantity leads to high species diversity environmental partitions allow species to coexist. D. Habitat complexity Environment has to have heterogeneity for niche partition to take place and allow many species to coexist leading to increasing diversity when habitat diversity is high. E. Competition Competition reduces the number of species. F. Keystone predators Helps maintain diversity since they prevent competitive exclusion. G. Disturbance Decreases the number of species but diversity is the highest at the mid way of the IDH (Intermediate Disturbance Hypothesis) 22. What is the paradox of the plankton and how can this apparent paradox ultimately be resolved? The paradox of plankton is that plankton live in simple environments and compete for the same nutrients, yet many species of plankton coexist without competitive exclusion. Plankton communities are dynamic and conditions are not as homogeneous as we think; conditions rarely favor one species long enough for it to exclude others. Species coexist when resources are fluctuating; fluctuating environment prevents competitive exclusion. -Can be resolved by putting constant flow vs. fluctuating flow of nutrients (silicon and phosphorus). 23. How will species diversity change when you increase the average supply rate of available resources vs. increasing the variation in resource types or amounts? Provide one example to support your reasoning in each case. Diversity decreases when you increase the average supply rate of available nutrients but it will increase when you increase variation in nutrients. 24. Ecosystem A has a primary production of 1000 g C m-2 y-1 and ecological efficiency of 10% Ecosystem B has a primary production of 300 g C m-2 y-1 and ecological efficiency of 20% -which ecosystem will have more production at the carnivore trophic level? Ecosystem B -which ecosystem is more likely to contain endothermic consumers? - Ecosystem A “This tells you the amount of energy available for the trophic level. So, 1000 x .1 = 100 units of energy is made from the herbivores. And if you do it again, you get (100 x .1) 10 units of energy 1. 2. l57 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - for the carnivores. It shows you how much energy is available at the given trophic level (From lecture I wrote that Jay said, "En = energy of any trophic level.") This can help us discover which ecosystem has more production at both the herbivore and carnivore level. From above: Ecosystem A: 1000 is the energy from the PP (primary producers) --> 100 for herbivores --> 10 for carnivores Ecosystem B: 300 from PP --> 60 for herbivores --> 12 for carnivores So we can see that there's more energy from carnivores in ecosystem B than in A, because it is more efficient. Ecosystem A most likely contains endothermic consumers since its less efficient (endotherms are usually less energy efficient in terms of production because a large portion of the energy goes toward regulating metabolic processes)” ^^ answer by someone on piazza 26. The figure below shows the distribution of energy and biomass across primary producers, herbivores and carnivores in three ecosystems. Based on the information provided, answer the following questions: a. which ecosystem has greater ecological efficiency, forests or grasslands? in the grasslands there is a lot of edible energy and thus many herbivores and thus many food for predators and in forest there's less edible energy(like trees) and so there's not many herbivores and thus less predators b. what differences in biological traits)between the organisms in grasslands and forests account for your answer for part a? Forests have lower production efficiency, higher metabolic demands c. which ecosystem(s) show evidence of top-down control of primary producer biomass? Open ocean LECTURE 26-27 1. 2. l58 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 1. If forest is fragmented into 4 equal sized patches, what happens to the edge to area ratio for this landscape? What is this effect called and how does it influence the environment of the patch and its ability to support species that live only in intact forested habitat? This is called habitat alterations and it is the fragmentation of a habitat into small patches which contributes to the loss of species. The edge to area ratio increases. (called edge effects) Some organisms need patches of a certain size to maintain themselves and if their habitat is fragmented they may no longer be able to live there. 2. The semelparous fish species, Oncorhynchus bistwobe, is a new major target of fishing. Most of these fish mature at five years of age and produce on average 1000 eggs when they spawn. Some individuals, however, mature at four years of age and produce on average 500 eggs when they spawn. If individuals are only harvested between ages 4 and 5, what level of harvest mortality will result in natural selection favoring the earlier-spawning individuals? Assume in the absence of fishing, all individuals of age 4 survive to age 5. 1) At age 4, there are there are 500 eggs produced, we will call this e = 500. For example, For age 4 = (o)(e) = (100)(500) = 50,000 eggs For age 5 = (s)(o)(l) = (0.5)(100)(1000) = 50,000 eggs You have to multiply by 0.5 because only half of them survived from age 4 to age 5. When we think of 50% mortality, natural selection is favoring both early (age 4) and late (age 5) spawning individuals because the number of eggs produced are equal for both age 4 and 5 at 50% mortality rate. In order to prove that natural selection is favoring early spawning individuals, the mortality has to be more than 50%. We can test this by making s a number that is less than 0.50, like 0.25, because that means that only 25% of the individuals live and there is 75% mortality rate. So, we would get For age 4 = (o)(e) = (100)(500 eggs) = 50,000 eggs For age 5 = (s)(o)(l) = (0.25)(100)(1000) = 25,000 eggs Because at age 5, there is less eggs produced than age 4, this shows that natural selection is favoring early spawning individuals. ^^ this makes sense but i don’t really follow it so if anyone wants to add their reasoning please do! How are we able to make this assumption about the survival rate?? Like what aspect of the question leads us to divide 500/1000 to find the survival rate? Thats what i dont understand because the question says to assume that all of them survive to age 5 … i think the person who wrote the answer might mean that 50% of the fish need to be killed for the number of fitness of the fish to be equal but it needs to be less than 50% for the smaller, younger fish to have a higher fitness The question asks “what level of harvest mortality will result in natural selection favoring the earlier-spawning individuals?” So probably on the test you could put in general mortality rates 1. 2. l59 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - like 80,70,60, or 50% to find what mortality rate will produce the same number of eggs produced as age 4. And when you find that mortality rate (which in this case is 50%) we can then say anything below 50% harvest mortality rate will result in natural selection favoring the earlier spawning individuals because anything under 50% will have age 5 fish producing less than 50,000 eggs for age 4. 3. Distinguish between complementarity and redundancy as mechanisms underlying diversity effects by giving an example of each and clearly discussing the biological characteristics of the species that contribute to diversity effects in both cases. -complementarity- species differ in the way they use resources such that more species means a greater fraction of the resources are used -more species decreases the probability of establishment of new species; invasion success decreases -many species means there’s few “empty” niches -An example of complementarity is different species of birds living in the same tree, but using different parts of the tree to nest. This increases diversity because more species of birds are able to live in the habitat. -redundancy- even when species are superficially similar, redundancy buffers against species lost (ecological spare tire) -simplified food webs are more prone to effects of species loss An example of redundancy is Otters and Lobsters where both eat sea urchins, so even though in certain areas the otter populations was greatly decreased, there was not as large of an effect because the lobsters could eat the sea urchins and keep their population under control, so the sea urchins did not decimate the kelp population. This contributed to diversity because the kelp is a foundation species that provides a habitat for many different species, and if it were to be decimated, the species richness would greatly decrease, and the area could turn into an urchin barren. 4. Rainforests found on islands throughout the Caribbean Sea have a number of endemic species (those found nowhere else but in the native forests of those islands). About 75% of the land area on the island of Cuba has been converted from native forest to either agricultural or urban use and is thus no longer available for use by these species. The graph below (next page) shows the number of species of reptiles and amphibians present on islands of varying size throughout the Caribbean. Use this curve to predict the approximate percentage of the 75 reptile and amphibian species originally found on Cuba that are in danger of going extinct due to habitat loss . 1. 2. l60 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - Cuba original land area is about 103,000 sq km . If Cuba lost 75% of the land area due to the conversion of native forest to agricultural or urban use, then the amount of land area lost is [(0.75)(103000)] = about 77,250 sq km . Leaving about 103000 - 77250 = 25750 sq km left , and when you go up the curve from 25750 km, you get about 50 species . If the original amount of species is Cuba is 75, and after conversion, there are about 50 species. That means that 75 - 50 = 25 and 25 species went extinct . To get the percentage of extinction due to habitat loss, it's 25/75 = 0.33 . 5. In order to estimate species loss in question 4, you needed to make an assumption that the remaining habitat on Cuba is more or less contiguous. Do you think that assumption is a valid one? Why or why not? Regardless of your answer, if the assumption were badly violated, how do you think that would change your answer for questions 7 (would the predicted number of species lost increase, decrease or stay the same)? The predicted number of species lost would increase (because many species need a certain amount of land to survive. If the land is no longer continuous, more habitats will be ruined and therefore, more species are likely to go extinct.) 6. As a result of road building, a formerly contiguous patch of tropical rain forest is now subdivided into smaller patches. The charismatic 8-striped purple newt lives in the forest, where it has long been among the most abundant species. The newt moves slowly and so cannot cross extensive areas of open ground that lack forest cover (e.g., a road) because it will dry out and 1. 2. l61 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - die. Conservation groups are interested in understanding the effect of all this road building on the newt, and have enlisted your services as a biological consultant. In your report, you should be able to provide short, well-justified answers to what you think the effects of road building will be on the ecology and evolution of the newt. For example, flow among newt populations, potential for local adaptation, species richness within a patch, spread of w will building roads affect: the risk of newt extinction, recolonization of patches after disturbance, gene disease, etc. Can you propose an engineering solution that might help avoid these impacts, yet still allow the roads to be built? Risk of extinction - high Recolonization of patches after disturbance - low Gene flow among newt populations - low Potential for local adaptation -high Species richness within a patch - low Spread of disease - low The question above mentions GENE disease- which would be high (inbreeding, recessive diseases). But regular disease, low would be correct (density dependent event) Solution to avoid these impacts: Tunnel underneath the road, similar to a corridor style or raise the roads to an above-ground system 7. The figure below shows the distribution of energy and biomass across primary producers, herbivores and carnivores in three ecosystems. Based on the information provided, answer the following questions: a. which ecosystem has greater ecological efficiency, forests or grasslands? in the grasslands there is a lot of edible energy and thus many herbivores and thus many food for predators and in forest there's less edible energy(like trees) and so there's not many herbivores and thus less predators b. what differences in biological traits)between the organisms in grasslands and forests account for your answer for part a? Forests have lower production efficiency, higher metabolic demands c. which ecosystem(s) show evidence of top-down control of primary producer biomass? Open ocean 1. 2. l62 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 8. What are the commonalities in the cause of all mass extinctions on Earth? How does our current situation compare with past (non-human caused) situations? Each mass extinction event resulted from dramatic global changes such as climate change, fluctuating sea levels, and extreme events. The mass extinction that may be unfolding currently is similar to those of the past because we are seeing some of those same occurrences characterizing past extinction events (global warming, sea levels rising, polar ice caps). 1. 2. l63 competition 3.

BIS2B FINAL STUDY GUIDE - Please use a different color other than black for answers thanks - 9. Match each of these events with its position (letter) on the timeline A - First photosynthetic bacteria evolve B - Eukaryotes evolve C - Evolution of multicellular organisms D - Multicellular aquatic animals evolve E - Cambrian explosion: origin and radiation of major animal phyla F - Colonization of land by plants G - Giant Flying insects H - First flowering plants evolve I - Anthropocene ^^someones answer on piazza i agree with Top (study guide timeline), bottom (lecture timeline) 1. 2. l64 competition 3.