chapter 23 - Chapter 23 THE EVOLUTION OF POPULATIONS The...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 23 THE EVOLUTION OF POPULATIONS The smallest unit of evolution One common misconception about evolution is that individual organisms evolve during their lifetime Evolutionary processes ( e.g., natural selection ) acts on individuals but populations evolve Mutation and sexual recombination produce genetic variation that makes evolution possible Variation within a population Discrete characters: classified on an either or basis - E.g flower color in pea plants Quantitative characters: vary along a continuum within a population - E.g., height, weight Mutation Change in nucleotide sequence of DNA - Source of new alleles and genes Point mutation: change in one nucleotide base in a gene Chromosomal mutations: delete, disrupt, or rearrange many loci on a chromosome Gene duplications: duplication of whole segments of a chromosome Mutation rate averages 1 in every 100,000 genes per generations Due to transposable elements, they are able to insert themselves into a sequence and disrupt it Sexual Recombination In sexually reproducing organisms, sexual recombination produces most of the variability in each generation. What provides selective pressure in artificial selection?
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the 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