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Homework Help: Genetics Heritability

  1. Dec 7, 2015 #1
    1. The problem statement, all variables and given/known data
    A geneticist studying the number of bristles on the second leg of fruit flies determined that a wild-type strain has a mean number of 486.3 bristles per leg. A sample of males and females from this population with 420.0 bristles were bred and the offspring had a mean bristle number of 432.0

    a) what is the heritability of bristle number?

    b) if you were to select a group of flies with 500.0 bristles and breed them, what would be the mean bristle number in the progeny?

    c) If we wished to generate a population of flies that had a mean leg bristle number of 450.0, what parents should we select?

    2. Relevant equations

    Vp = Va + Vd + Vi + Ve + V(g)(e)

    Vg = Va + Vd + Vi

    H^2 = Vg / Vp

    h^2 = Va / Vp

    3. The attempt at a solution

    I honestly don't even know where to begin. I have tried contemplating for 20 minutes on what to freaken do and I'm getting very frustrated. If someone could PLEASE at least point me in the right direction (I get it if you don't wanna solve it) then I would really appreciate the help. My teacher is no good.

    Thank you very much
  2. jcsd
  3. Dec 8, 2015 #2


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    Homework Helper
    Gold Member

    This is some kind of quantitative genetics I have no acquaintance with and I don't know if anyone who has will be along.
    I don't know what any of the symbols in your equations are.

    But I recognize a pattern of question which we get about pH buffers, resistive circuits, stoichiometry, and other standard subjects.

    That is there is a textbook definition and the student is asked to apply it calculating something. That is question (a). The definition of herediBlity is surely in your textbook and sufficient relevant data in your question.

    We might or might not be able to help with the others if you posted a relevant Page or two from the book here.
  4. Dec 8, 2015 #3


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    Science Advisor
    2017 Award

    The equations you should use are not among those listed in the first post (those are a more general definition of heritability, but are not the right ones for the particular experiment you describe). You should review the relevant part of your textbook on calculating heritability from the response to selection. (Alternatively, read https://www.ndsu.edu/pubweb/~mcclean/plsc431/quantgen/qgen7.htm or take a look at slides #13-14 from http://www.wou.edu/~guralnl/311Quantitative Genetics.pdf).

    Once you've reviewed that material, try posting your thoughts and we can tell you whether you're on the right track.
    Last edited: Dec 8, 2015
  5. Dec 8, 2015 #4
    Yes Ive looked at the definition and it confuses me, but I will try to look for other equations to use
    Thank you!
  6. Dec 8, 2015 #5
    Thank you very much, I will review those now as well as look for different equations!
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