lec_6_cond_13

# How much change next generation average of population

This preview shows pages 3–5. Sign up to view the full content.

(How much change next generation) average of population relative number 0 0 average of selected G=0 G=1 900 692 0 0 900 seed size (mg) average of population 404 average = 404 average = 692 relative number average of selected G=0 G=1 Parents average of population Observed Results 0 0 900 average = 404 692 0 0 900 seed size (mg) Offspring average is in between 404 & 692 average = 609 So response to selection depends on how much phenotypic variation is due to genetic variation among individuals, i.e. heritability average seed size increased by 51% To predict future change in response to selection we need to estimate heritability. Note: The symbol for heritability is h 2 not h, so h 2 is not heritability squared 27

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

View Full Document
R S 692 - 404 = 288 R=609-404=205 S=692-404=288 609 - 404 = 205 relative number 0 G=0 G=1 0 0 900 seed size (mg) average = 609 To estimate heritability, we need to define 2 parameters Selection Differential = strength of polygenic selection = AVE(selected) - AVE(whole pop) = S average of selected Parents Offspring 900 average = 404 692 S = To estimate heritability, we need to define 2 parameters Response Differential change in population due to polygenic selection = R AVE (whole pop.in G=1) AVE (whole pop.in G=0) = = = - relative number 0 900 average of selected G=0 G=1 Parents 0 0 900 seed size (mg) Offspring 692 R average = 404 average = 609 relative number 0 900 average = 404 692 G=0 G=1 Parents 0 0 900 seed size (mg) average = 609 Offspring Realized heritability = proportion of polygenic selection that is manifest in offspring = R / S = estimate of heritability (h 2 ) 205 288 = 205 / 288 = 0.71 Realized heritability can be expressed as a slope with family data slope = 1 is PERFECT heritability slope = 0 is NO heritability Intermediate heritability Average phenotype of offspring Average phenotype of parents 28 The slope of the average phenotype of parents vs. the average
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• 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.

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

• 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.

Dana University of Pennsylvania ‘17, Course Hero Intern

• 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.

Jill Tulane University ‘16, Course Hero Intern