1. In this lab, we were assigned a phenotype, stumpys, knucklers, or pinchers. These were all phenotypes of birds. The objective of the lab was to pick up enough food to both survive and reproduce. The amount of food, which was represented by wine bottle corks, needed to survive and reproduce changed depending on the year. stumpys could only pick up food with their wrists. knucklers could only pick up their food in between their knuckles, excluding thumb. The pinchers could pick up their food by pinching the corks in between their thumb and index fingers. This lab simulated natural selection by highlighting which phenotypes could survive and reproduce most.
2. The knucklers were the best at capturing food because they had a large and flexible mouth in which multiple pieces of food could fit. One of the most efficient tricks to picking up food as a knuckler was to stack pieces of cork on top of each other picking up 2 pieces of food at a time. This would double the amount of food picked up, and lead to a flourishing population.
3. I found that the population greatly evolved in favor of the little "a" allele, which was the knucklers and pinchers. In the first 3 years, there was a constant increase in the "a" allele, and a constant decrease in the "A" allele. The "a" allele frequency after the first trial, second year, jumped from 0.5 to 0.67, and then even further up to 0.72 in the third year. The "a" allele rose to almost 75% of the gene pool, and stabilized at that level. This causes evolution, because evolution is a change in allele frequency.
4. The location of food was random to an extent. For some trials, the food was all placed in a pile, where the fastest of all participants would reach the food the quickest. For the most part however, the placement of the food was random. This was similar to genetic drift, where the location of the food would affect the population, whether it be drastic or minuscule. Sometimes there would be a major decrease in population, or even phenotype size due to the placement of food. When the food was spread out over a wide area, stumpys had great difficulty picking up food, but knucklers and pinchers had great success. If the food was in large piles, then the knucklers and pinchers had less of an advantage over the stumpys. Another random factor was the amount of food necessary to survive and reproduce. This also included whether or not there was plastic among the food. The participants never knew how much food was needed or whether or not they would survive. The one year there was a spike in plastic in the food source, there was a drastic change in the population. The population decreased by over half. However, a non-random factor was who mated with who. This was a form of sexual-reproduction, since participants usually mated with friends rather than strangers. Based on this factor, what phenotype their offspring had was totally random, which sometimes stopped the population from evolving. Even if two pinchers mated, there was chance of having a stumpy. This prevented evolution, which would have gotten rid of stumpys.
5. The results would have been very different if the food was a different size. Depending on how much the food size is increased, the stumpys would have less to no disadvantage, considering that it is much easier to pick up larger food with your wrists. The pinchers and knucklers would also lose their advantage, and if larger enough, the food would be too big for their mouths to pick up. If the food was smaller, then the pinchers and knucklers would have even more of an advantage. This means that the stumpys would go extinct much quicker, and the pinchers would rise to the top of the food chain. In nature, evolution occurs throughout the food chain, which means that predators must deal with different size foods. As the food evolves, the predators must evolve to eat this food. This occurs by change in phenotypes. Some phenotypes go extinct while others flourish.
6. The results would have been very different if there was not incomplete dominance. If there was natural evolution, then the population would have been void of stumpys within the first 4 years. The knucklers would have also dominated the population by the fourth year. This would have lead to evolution that favored the knucklers.
7. Natural selection causes allele change, and evolution is allele change. In other words, natural selection causes a change in the gene pool. The change favors the alleles that help the organisms survive and reproduction. This change in allele frequency is evolution.
8. I am not sure of any strategies that pinchers used, but as a knuckler, I doubled my food intake by grabbing two pieces of cork, one after the other. Instead of picking up each piece and saving it, I would do something similar to stacking them on top of each other. This doubled my food intake and helped me survive and reproduce all seven years. Stumpys, on the other hand, had trouble picking up any food in general. This is where they adopted the strategy of covering the food from competition, and waiting until it was safe to pick up their food. This helped a few organisms survive, but that phenotype was at a disadvantage.
9. The population evolves into organisms with the desirable traits that help it survive and reproduce. Natural selection acts on both the genotype and the phenotype. Natural selection affects both the genotype and the phenotype. The genotype's physical expression is the allele, which is the phenotype.
10. The only question I have is where to the alleles come from in the first place. If a population is made up of organisms with a certain allele, where does the new allele come from when evolution occurs. I know it comes from certain organisms with that new allele, but where did that organism get that new allele?
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