Lecture_11 - I Population Genetics A Genotypic Allelic...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
I. Population Genetics A. Genotypic & Allelic Frequencies B. Hardy-Weinberg C. Natural Selection Reading: Chapter 21 pg 757-768, Problems: 2-8, 18 Intro to population Genetics As I stated in my first lecture, the goal of this portion of the course is to start answering the question: what accounts for the variation among organisms that we observe – both variation among individuals of a species and variation among species. Of course what we're particularly interested in is the GENETIC basis of these differences and how they have arisen. Thus far, we've seen how Mendelian Genetics can describe the passage of traits through generations (pedigrees) - where given some information about the genetic nature of a trait you can predict the phenotypes and genotypes of future generations. Now we're going to move to a higher level, namely populations, to learn how we can describe the phenotypes and genotypes of populations of organisms and how these phenotypes and genotypes may change through time and space. POPULATION GENETICS First we need to describe the genetic variation within a population before we can describe how that might change. Two basic frequencies: Genotypic frequency Allelic frequency MN blood groups in humans: similar to the ABO blood groups - in that M & N alleles produce antigens on the surface of red blood cells In a sample of 1000 British people - were typed for MN blood groups: MM - 298 people MN - 489 NN - 213 1000
Image of page 1

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

View Full Document Right Arrow Icon
In terms of GENOTYPIC FREQUENCIES: MM - 0.298 MN - 0.489 NN - 0.213 sum = 1.00 In terms of ALLELIC FREQUENCIES: 298 MM individuals have 596 M alleles 489 MN individuals have 489 M alleles
Image of page 2
Image of page 3
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