Nathaniel Sirak ANT LAB 1

ANTH 215: NAME____Nathaniel Sirak_______________________ Lab 1 - Forces of Evolution: Genetic Drift Activity Objectives: This activity will demonstrate the effects of genetic drift on a small population. Procedures: 1. Grab a bag of Skittles/M&Ms/beads/something similar and a paper towel; this represents the original population of the Colored candius organism. 1. Count the number of Skittles in your baggie and record this data in Table 1. 1. Count the number of each color and record this in Table 1 under “Whole Population” 1. Calculate the percentage of each color present in this population % = # of colored skittle # of whole population x 100 1. Open your baggie and WITHOUT LOOKING, remove 6 Skittles and place them on the paper towel; this represents the genetic drift population. 1. Count the number of each color and record this in Table 1 under “Genetic Drift Population” 1. Like before, calculate the percentage of each color in this population. 1. Enjoy your Skittles as you answer all post lab questions. Table 1: Population Numbers of Original and Genetic Drift Populations Original Population Genetic Drift Population Amount Percent % Amount Percent % Whole Population 108 100% 6 100% Red Skittles 16 14.81% 1 16.66% Orange Skittles 32 29.63% 2 33.33% Yellow Skittles 24 22.22% 1 16.66% Green Skittles 25 23.15% 2 33.33% Purple Skittles 11 10.19% 0 0% Post lab questions: 1. Look at your tables for each generation. Does the new genetic drift population accurately represent the original population? Why or why not? Cite the data where necessary?

No. The information and data displayed by the 'Original Pop.' & the 'Genetic Drift Pop.' do NOT accurately reflect each other. The population of the 'genetic drift' sample was randomly selected out of 108 objects. 6 were selected making the chance for an accurate representation of skittles color distribution quite flimsy 2.What colors in the original population are NOT represented in the genetic drift population? The purple skittles were not represented in the genetic drift population. 3. When you compare the percentages of each color, are they the same for the original population and the genetic drift population? Explain. No, these are not the same since they were for the indigenous population. This is because the general drift did not include all of the colors that were available. 1. Let's assume that the Skittles are a species of Preying Mantises and that the new environment consists of lots of greenery and many bright red flowers. a. Which colors in the genetic drift population would have better fitness in this new environment? Why/how? Every color except purple would have good fitness regardless of the environment, simply because they were the only colors expressed in the genetic drift population. a. How might that affect the alleles for those individuals? In other words, will the alleles for those individuals increase/decrease or stay the same? Explain. The new population is very small consisting of only six members with only two different traits. The yellow and green colored-ness trait would be the only one possessed from the alleles of the original pop. Furthermore, given the addition of a natural selection. The allele expressed for colored- ness would probably result in a much lower allele frequency of the other colors. (But I think the other colors COULD resurface potentially unless the six of the genetic drift pop. expressed homozygous alleles for the yellow and green colors). Still, the alleles of yellow and especially green would exponentially increase from generational population to generational drift population. a. Which ones would have less fitness? Why/how? What might happen to the alleles for those individuals that have less fitness?

3. Mutations - The unpredictable change within the sequencing of DNA code that is only an evolutionary force when in sex cells that result in new 'mutated' organisms. 4. Gene Flow - The process of a gene being carried from one population to another. 5. Natural Selection - The process of individuals with traits less conducive to reproductive success within their environment disappearing from a population. 1. You have a lot of pet goldfish in a tank in your living room. You started your fish colony a couple of years ago from just 4 goldfish that were from the pet store (likely heavily inbred =very little genetic variation). One day you are cleaning the tank and notice a new juvenile fish with an unusual red spot on his tail. It is the only one in the population with this spot. What might be influencing this population? Why? This circumstance of a randomly appearing trait sounds like a case of mutation. Mutation, which is a spontaneous change in genes for an organism being reproduced, is "the only mechanism that creates novel genetic variation" (Module 3 PP). Novel genetic variation would be necessary to influence high chances of a new change amongst a population started from founders with 'very little genetic variation. 1. You are a chicken farmer in Hyattsville, MD and you have lots of chickens. Some lay brown eggs and some lay white eggs. By doing some quick counts over the past few weeks you see that your chickens lay about 80% white eggs and 20% brown eggs. A flash flood strikes your farm the next week. You save two of your 6 coops, the rest of the chickens are washed away. You move your remaining lucky chickens to higher ground, re-building the farm. Six months later, you re-do your egg count to find that your chickens are laying 60% brown eggs and 40% white eggs. What might be influencing this population? Why? In this scenario, we see a normal population's gene drastically altered by a random event. This transition of genes is due entirely to environmental chance. Thus this situation seems to fall under the label of a Genetic Drift in which a certain allele wasn't lost but decreased due to a random environmental event.

1. Bower birds are unique to Australia. These ground dwelling birds build elaborate grass nests and decorate them with brightly colored objects (often bits of trash and plastic) to attract a female. The birds use all sorts of colorful items and arrange their displays to try to be most appealing to the female (either using all one color of item or creating a rainbow jumble of plastic trash!) and arrange them artfully to attract females. The females choose their mates based on the brightness and elaborateness of the male’s nest displays. Why might these birds have evolved into such fantastic animal architects? The Bower bird is an exemplary case example of Non-Random Mating. The Bower birds develop the display of nesting architecture to attract a companion for mating. If they have the ability to successfully attract the female, then they can reproduce. This attraction presents the event of Non-Random Mating, which specifically includes a mate selection influenced by observable differences affecting geographic and cultural success rather than biological differences. The observable difference portrayed by these birds is their fantastic shelter and nest architecture. 1. You decide to move to a remote island in Polynesia to conduct Anthropological ethnographic fieldwork. However, you refuse to leave your two Maine Coon cats behind, so you bring them with you to the island. The local stray cats on the island are all short haired, striped brown tabby cats. Your cats love to explore so you let them outside every night. A few years into your fieldwork you start to notice that the local island cats are looking different these days. You see many with bushy tails and some with long fur. What might be influencing this population? Why? Gene Flow. Gene Flow is conducted when a population migrates within the area of a different population. It can happen within natural or unnatural migration and results in an altered allele expression for the domestic population (in this case the local stray island cats of Polynesia).