MechanismofEvoTable - founder events cause population...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Mechanism of Evolution Effect on genetic diversity within & between populations Migration Movement of individuals (genes) between increases the number of alleles/genotypes population of the same species. per population. Decreases the differences in genetic composition among populations Mutation Random changes to the DNA sequence increases number of alleles & genotypes as a result of errors during replication. per population. Because mutations are Is the source genetic variation but doesn’t different each time, they enhance differences have a large influence on allele freq. in genetic composition between populations Genetic drift Random changes in the Decreases number of alleles/genotypes per frequency of alleles and genotypes. population. Populations will change in Strongest when the number of individuals different directions and thus drift increases in the population is low – as some differences in genetic composition between genotypes will contribute more than populations. another just due to chance. Bottlenecks &
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: founder events cause population crashes which leads to drift. Natural Selection Non-random difference in reproduction & Generally (directional) selection leads to a survival (fitness) among phenotypes in a decrease in the number of alleles/genotypes particular environment. Phenotypes best per population. If different populations have equipped for a particular environment have different environments, natural selection can the highest fitness. increase differences between populations. Non-random mating The tendency for individuals to mate Causes no change in allele diversity, but with other individuals of the same affects genotype diversity. When most phenotype (and genotype) more mating is between similar phenotypes often than random. Can also refer to then the frequency of homozygotes consistent mating between different increases. When most mating is between phenotypes. dissimilar phenotypes (& genotypes) then the frequency of heterozygotes rises....
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern