How to Calculate Heritability in Fruit Fly Bristle Number Genetics

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Discussion Overview

The discussion revolves around calculating heritability in the context of fruit fly genetics, specifically focusing on the number of bristles on the second leg of fruit flies. Participants address a homework problem that includes determining heritability, predicting progeny traits, and selecting parent flies for desired traits. The scope includes quantitative genetics and application of relevant equations.

Discussion Character

  • Homework-related
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant expresses frustration with the homework problem and seeks guidance on how to begin, indicating a lack of understanding of the concepts involved.
  • Another participant suggests that the problem resembles standard textbook questions and implies that the definition of heritability should be found in the student's textbook.
  • Some participants note that the equations provided in the initial post are general and not suitable for the specific experiment described, recommending the student review relevant textbook material on heritability from response to selection.
  • There is mention of external resources that could aid in understanding the calculations needed for the homework.
  • One participant acknowledges confusion with the definitions and expresses intent to seek alternative equations for the calculations.

Areas of Agreement / Disagreement

Participants generally agree that the initial equations may not be appropriate for the problem at hand and that reviewing textbook material is necessary. However, there is no consensus on the specific equations or methods to be used, as participants express varying levels of familiarity with the topic.

Contextual Notes

Some participants indicate a lack of familiarity with the symbols and terminology used in the equations, which may limit their ability to assist effectively. The discussion reflects uncertainty regarding the appropriate approach to calculating heritability in this specific context.

Who May Find This Useful

This discussion may be useful for students studying quantitative genetics, particularly those encountering similar homework problems related to heritability and trait selection in fruit flies.

CMATT
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Homework Statement


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?

Homework Equations



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

Vg = Va + Vd + Vi

H^2 = Vg / Vp

h^2 = Va / Vp

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 want to solve it) then I would really appreciate the help. My teacher is no good.

Thank you very much
 
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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.
 
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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.
 
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epenguin said:
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.

Yes I've looked at the definition and it confuses me, but I will try to look for other equations to use
Thank you!
 
Ygggdrasil said:
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.

Thank you very much, I will review those now as well as look for different equations!