Population Genetics Problem #1

Dan Schoen and Mike Clegg (Evolution 39:1242-1349; 1985) studied the influence of flower color on the outcrossing rate in the common morning glory, Ipomoea purpurea. Focusing just on results from the first experimental design and ignoring the color differences, these are the data they report:

	Offspring genotye
Maternal genotype	$Est^FEst^F$	$Est^FEst^S$	$Est^SEst^S$
$Est^FEst^F$	267	62	0
$Est^FEst^S$	81	120	44
$Est^SEst^S$	0	143	170

When plants reproduce by a mixture of self-fertilization and outcrossing the expected frequencies of getting a particular offspring genotype, given the mothers genotype can be written as

	Offspring genotye
Maternal genotype	$Est^FEst^F$	$Est^FEst^S$	$Est^SEst^S$
$Est^FEst^F$	$p_m\tau + (1-\tau)$	$q_m\tau$	0
$Est^FEst^S$	$\frac{p_m\tau}{2} + (1-\tau)/4$	$\frac{1}{2}$	$\frac{q_m\tau}{2} + (1-\tau)/4$
$Est^SEst^S$	0	$p_m\tau$	$q_m\tau + (1-\tau)$

where $p_m$ is the frequency of the $Est^F$ allele in successful male gametes and $\tau$ is the fraction of offspring produced through outcrossing.

Using these data answer the following questions:

1. What is the outcrossing rate in this experimental population?

2. Is the allele frequency in maternal plants equal to the allele frequency in pollen that participates in fertilization?

3. What is the inbreeding coefficient in the maternal plants?