A researcher is interested in whether male killifish
with bright colors have favorable alleles, in various parts of
their genome unrelated to color pattern, that fight off disease. He
captures thirty males in the act of copulating with females, ten in
each of three categories, and collects sperm. The three categories
are BRIGHTEST COLORS, MEDIUM COLOR, KINDA DULL COLOR. Next, he
fertilizes killifish eggs, all from the same female, in batches,
with sperm from each of these male fish. The offspring are raised
to adulthood, and exposed to an aquarium parasite,
ich.

a)   
Imagine the researcher got the following data.

Offspring of Bright Color males, average survivorship;
83% +/- 8% Std error

Offspring of Medium Color males, average survivorship;
61% +/- 11% Std error

Offspring of Kinda Dull Color males, average
survivorship, 31% +/- 16% Std error

What do these results suggest?

b)   Why not
just let the female choose whatever male she wanted? Why this
business of collecting sperm from males she never met? Std error is
shorthand for standard error of the mean, in this case, mean
survivorship of the ten groups of eggs fertilized by males in the
same category. Why did the researcher list it? Would the data be as
credible without it?