Peppered moth simulations
Many factors can cause a population’s genetic structure to change. When a population’s genotype and allele frequencies change over time, the population is said to be evolving. The Hardy-Weinberg Equilibrium Theory is used in population genetics to determine whether these factors act on a population and in turn, whether it is evolving or not. An experiment was conducted using the peppered moth PopGenLab software to test how disassortative mating affects a population of only black and brown moths. It was assumed that the white moth would be reintroduced to the population with a 75% increase of disassortative mating. The hypothesis was supported and it was determined that the white moth phenotype increased to about 21% over time with continued disassortative mating pattern.
Introduction
This research paper addresses a question regarding how a population’s genetic structure can change over time. The question asked was, can increasing the amount of disassortative mating reintroduce the white phenotype in an initial population without the white phenotype. For this experiment, it is assumed that increasing the amount of disassortative mating will cause the white phenotype to reappear in a population that started without the white phenotype. This question can be further explained by background information on population genetics.
In genetics, it is important to study a population as a whole and how it interacts with other populations. This area of genetics is called population genetics. Studying certain genes and the frequency of their alleles and genotypes in each generation can give us information about the behavior of the population. A genotype frequency is the frequency of different allelic variations of ...
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...mating to a full 100% would not reintroduce the white phenotype because the brown phenotypes “Aa” would only mate with black phenotypes “AA”, not being able to form the white phenotype “aa”.
Literature Cited
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One of the phenotypes was poorly adapted for capturing wildloops. What is a possible explanation for why the nonadaptive alleles for this phenotype do not get removed from the population entirely over the course of many generations?
Zhao, Buyun. "Charles Darwin & Evolution." Charles Darwin & Evolution. Christ's College, 2009. Web. 04 May 2014.
ImageText BoxImageOne of the biggest threats to the environment of Ontario is the Gypsy Moth (Lymantria dispar dispar). The species itself is native to Europe and Asia. How this affects us is by weakening trees across Ontario and North America. The first time the gypsy moth was found in Ontario was 1969. The gypsy moth can be found in southern Canada (Ontario), New Brunswick, Nova Scotia and British Columbia. It is known to weaken trees and the caterpillar form live in trees and during most outbreaks its caterpillar feces would fall from the trees to the ground or even on top of humans. The average Gypsy Caterpillar can grow 5-6 centimeters long. With five pairs of blue spots and six pairs of bright red dots on their back. The female moth are white and can fly on the other hand, the male moth are brown and can also fly. The female have a 5cm wing span but male have a 2.5cm wing span. The gypsy moth usually lives in open forests and other forests and take up at least 20% of the space. The Gypsy moth are about 4cm long, tan coloured and can be located on tree trunks, furniture, and buildings. (OFAH Invading Species Awareness Program, 2012)
Biological evolution is a change in the characteristics of living organisms over generations (Scott, 2017). A basic mechanism of evolution, the genetic drift, and mutation is natural selection. According to Darwin's theory of evolution, natural selection is a process in nature in which only the organisms best adapted to their environmental surroundings have a higher chance of surviving and transmitting their genetic characters in increasing numbers to succeeding generations while those less adapted tend to be eliminated. There has been many experimental research projects that relate to the topic of natural selection and evolution.
Darwin: A Norton Critical Edition, Second Edition ; ed. by Philip Appleman; copyright 1979, 1970 by W.W. Norton & Company, Inc.
There are few factors that can alter the proportion of homozygotes and heterozygotes in a population: genetic drift, gene flow, mutation, and natural selection. Genetic drift is the change in the gene pool that occurs in a small population due to chance. For example, let's say we are talking about a species of fish called Drew fish, well the Drew fish population was hit by an oil spill and many of them died. The remaining survivors form new colonies, and this results in genetic drift, the founder effect. Gene flow is about the movement of alleles. Well let's say a Prow Fish began to mate with the Drew fish this will bring about some gene flow because these Prow Fish are just the same species as Drew fish but a different population with different alleles, so they have yellow fins as oppose to blue.
Some individuals have developed different traits to help them in the process of intra-sexual competition. The organisms with more distinctive traits have greater reproductive success. More genes of those traits are then ‘selected’ and are passed onto the offspring of the organisms. Throughout time variability in these traits becomes
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Rantala, M. J., and Roff, D. A. 2006. Analysis of the importance of genotypic variation,
The idea of the project was to experiment breeding Drosophila Melanogaster (fruit fly) to figure out if certain genes of that species were sex linked or not (autosomal). A mono-hybrid cross and di-hybrid cross was performed. For the mono-hybrid cross, white eyed female and red eyed male were placed in one vial for them to reproduce. For the di-hybrid cross, red eyed and normal winged flies and sepia eyed and vestigial winged flies were placed in their vial to reproduce. In the mono-hybrid cross the results expected were within a 1:1:1:1 ratio. Expected results similar to the expected desired null hypothesis proposed with what the F1 parental generation breeds. The potential results would have had to have been within the ratios of 9:3:3:1. The results were clear and allowed the null hypothesis to be correct. The white eyed gene in the fruit flies is sex linked. Sepia eyes and vestigial wings are not sex linked and are examples of independent assortment.
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more than half the variation was found to be due to heredity. Among these traits were
Evolution is defined as the change of hereditary characteristics of populations over generations (Caroll, 2009). The environment is continually changing therefore organisms have to change in order to stand the changes in environment so they can survive and reproduce (Caroll, 2009). Regular change in genetic material of organisms over generations can lead to the development of new species that are more adapted to the environment (Caroll, 2009). It is said that failure to evolve may lead to extinction of a species (Caroll, 2009).
“Heredity Versus Environment – The Nature – nature controversy, exploring heredity and environment: Research Methods, beyond heritability”