week 10: quantitative genetics · week 10: quantitative genetics joe felsenstein genome 562 week...
TRANSCRIPT
-
Week 10: Quantitative Genetics
Joe Felsenstein
Genome 562
Week 10: Quantitative Genetics – p.1/11
-
The Biometricians
Francis Galton (1822-1911) Karl Pearson (1857-1936)
Week 10: Quantitative Genetics – p.2/11
-
Francis Galton sees a law of heredity
... or what he thinks is one. These days we’d just say he saw a bivariatenormal distribution.
Week 10: Quantitative Genetics – p.3/11
-
Ronald Aylmer Fisher (1890-1962)
about 1930 in 1952
Fisher, R. A. 1918. The correlation between relatives on the supposition ofmendelian inheritance. Philosophical Transactions of the Royal Society ofEdinburgh, 52: 399 – 433.
Week 10: Quantitative Genetics – p.4/11
-
A one-locus quantitative character
Week 10: Quantitative Genetics – p.5/11
-
A two-locus quantitative character
Week 10: Quantitative Genetics – p.6/11
-
Distributions with different numbers of locin = 1 n = 2
n = 10n = 5
Each has a number of completely dominant loci (all of equal effect), withsize of effects scaled so that overall genetic variance is equal, and with an
environmental effect that contributes 20% of the variation.Week 10: Quantitative Genetics – p.7/11
-
Regression of offspring on a parent
6 8 10 12 14
6
8
10
12
14
Off
sp
rin
g
Parent
Week 10: Quantitative Genetics – p.8/11
-
Regression of offspring on a parent
−4 −2 0 2 4
−4
−2
0
2
4
Parent − Mean
Off
sp
rin
g −
Mean
Week 10: Quantitative Genetics – p.9/11
-
Regression of effects at one locus on gene dose
a12
a11
a22
0 1 2
11
12
22
x (dosage of A )1
a
δ
δ
δ
+1 1
α α
+α αα α+
1 22 2
ij
Week 10: Quantitative Genetics – p.10/11
-
Jay L. Lush (1896-1982)
about 1960 Animal Breeding Plans
Week 10: Quantitative Genetics – p.11/11
The BiometriciansFrancis Galton sees a law of heredityRonald Aylmer Fisher (1890-1962)
A one-locus quantitative characterA two-locus quantitative characterDistributions with different numbers of lociRegression of offspring on a parentRegression of offspring on a parentRegression of effects at one locus on gene doseJay L. Lush (1896-1982)