Problem Set 6

pdf

School

University of California, Santa Barbara *

*We aren’t endorsed by this school

Course

Subject

Anthropology

Date

Dec 6, 2023

Type

pdf

Pages

Uploaded by JudgeStorkPerson684

Anthropology 005 Problem Set # 6: Language, recent selection, imperfection, and sex Fall 2022 1. I argue in this course that language (not specific languages like French or Mandarin or Aymara, but the ability to learn and use language) is an important derived adaptation that emerged in the hominin lineage. A. To a biologist, what is a byproduct? A byproduct is the outcome of any process which is being carried out along with the main product. B. Is language a byproduct? If so, what is it a byproduct of? If you think it is not a byproduct, why do you think that? Language is a byproduct of large brains. It is a byproduct because there are certain parts of the brain that are dedicated to language. Selection favors language being a product because its useful despite its costs. C. Non-human animals communicate with each other (signaling present danger, aggressive intentions, interest in mating). Should we regard that kind of animal communication as language? Explain why or why not. Non-human animals communicating with each other can be considered a language. Animal communication does not include verbal communication, but they have other forms of communication for example signaling or physical actions. It is still a language since there is a form of communication. Language does not have any “rules” to it. 2. On Problem Set #2 you answered this question: “What happens to haplotypes in every generation, as an inevitable consequence of meiosis?” You should review your understanding of that, because it is the key to unlocking question 2B below. A. First a very easy question: How do we recognize alleles that have been favored by natural selection? We can recognize alleles that have been favored by natural selection by seeing if they have a high frequency in the population, since it has been positively selected. B. How do we recognize alleles that have recently been favored selection, as opposed to those that have spread through the population farther in the past? Explain your answer. We can recognize an allele that has been recently favored for selection because it will have less of a variation in its genes as opposed to ones that have spread through the population farther in the past. One that has spread father in the past will have a lot of variation to it. 3. Throughout this course we have emphasized the power of natural selection to design adaptations. A. Begin by restating for yourself how that process works; how do adaptations come about? Adaptations is a change that allows an organism to become better suited to its environment. Adaptations improve an organism's fitness while giving it a higher chance of survival.

B. Chapter 19 explores why organisms are not always well adapted to their environments—why they have traits that lower their fitness or seem poorly designed, and offers four distinct reasons. One of those is “evolutionary time lags”. Please define adaptation as we have in this course. As stated in the textbook, adaptation is a trait preserved by natural selection because it improved the fit between the organism and its environment. C. Now, use that definition to explain when you expect to see evolutionary time lags. Based on the definition of adaptation, we can see an evolutionary time lag when the survival rate for a certain organism is very low. That can be an example because selection may stop favoring which causes fitness reduction. D. Give at least one example of an evolutionary time lag not discussed in your textbook or lecture. An example of an evolutionary lag can be anything that causes an imperfection in somethings thats clearly organized. An example would be an organism that is adapted to an area but eventually the adaption does not benefit it anymore. 4. Sex has been called “the masterpiece of nature” and that is not an indefensible claim. Nevertheless it, like altruism and homosexuality, is an evolutionary puzzle because it has considerable costs relative to its alternative, asexual reproduction. A. Identify three separate costs of sexual reproduction that are not experienced by asexual organisms; be sure to explain the nature of each cost and make sure you have differentiated it from the other two. The three separate costs that are not experience by asexual organism are meiosis, recombination, and outcrossing. Asexual organisms get all their genes in each of there offprings. In recombination, asexual offsprings are genetically identical to their parents.. And as for outcrossing asexual organisms reproduce whenever they are ready as apposed to a sexual organism which requires much more effort. B. The Red Queen Model attempts to explain why sexual reproduction has evolved despite these costs. In this model parasites and pathogens play a key role. Explain why they are thought to be critical to the evolution of sex. (Hint: If correct, your answer to 3C should help.) They are critical in the evolution of sex becasue they both have negative inheritances. Its exploiting the genotypes. C. Chapter 20 describes an elegant lab-based experimental test of the Red Queen Model. But we also taught you how to use the outcomes of evolution (convergence and/or divergence) to test hypotheses based on what we see in nature. Please use your evolutionary knowledge to suggest how you might use the comparative method to devise a different test of the Red Queen Model. [Hint: what kinds of species might be favored to give up sex, the way cave fish have given up eyes?] We can use the comparative method to devise a different test of the red queen model by making a bigger list of comparison’s, benefits, disadvantages, and differences.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Problem Set 6

Related Documents