Natural Selection Scenarios

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Natural Selection Paper A. Natural selection scenario Essay When we talk about natural selection, we will think about mutation, genetic variation, and differential reproductive success etc. Mutation is meaning the change of genome orders that make the species change. Genetic variation means the change of alleles inside the genes, this change happens over time, is very important for Natural selection, because is the starting point of natural selection. We will also consider about differential reproductive success for natural selection. Because the higher success rate of the reproduce, the higher the species get selected, so the differential reproductive success is also a key factor of natural selection. Fitness and Adaptation decides the…show more content…
Our population is number 5, the environment we have is Hedgerow, in the environment most of the flowers are green and pink. Our population is round small paper chips. The character for the population is body color. Our dominant allele is G, and recessive allele is g. There are three kinds of phenotypes; green color with an o is homozygous dominants (GG), green color with a + is heterozygote (Gg), and brown color with an o is homozygous recessives (gg). At the beginning we total 100 populations, 25 brown and 50 green+ and 25 green o. We put these 100 populations into the environment, spread them evenly. We choose a group member as the predator. Predator needs to close his eyes while we spread the chips, and while the predator is hunting, he could only use his eyes, when he see the chip, then he use his hand to pick it up. We need to pick 50 chips out of the 100 population, and then count the number of each kind chips left in the environment, then we calculate the expected frequencies of each genotype of this 50 survivors’ offspring, then we get a new generation. We repeat this process three times, and find out what’s the total number offspring of each kind of chips. Also, we have three different…show more content…
Also because all the chips are steadied in the environment, so once have been seen, then will be hunted for sure. Because of the brown phenotype is influenced by g genotype, so as the brown chips decrease, the relative frequency for the allele g also decreased. Same as G genotype, because increase in green chips, allele G also increased. From calculation the relative fitness value, we get: GG: 0.93, Gg: 1, gg: 0.32 So that, in our case, genotype Gg have the highest fitness value, but gg has much smaller fitness value. The only way to increase survival chance is to change the body color from brown to green. From this experiment, we can know that Hardy-Weinberg equilibrium is impossible to reach in the real world, because there always be one condition not met the requirement for the equilibrium. If in our population, all the color is green, then maybe we can reach the Hardy-Weinberg equilibrium. 4. Conclusion Compare our graph with the class average graph for population five, they are identical, the shapes of two graphs are the same, both have G allele increase, and g allele decrease, the only different is that our frequencies for the two alleles is more spread out, their difference is larger than the class average; this is because we have a smaller population
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