This effect dominates over additive genetic effects as the ruggedness of an adaptive landscape increases. For 10 points each:
[10m] Name this effect in which a modifier gene “masks” or alters the phenotypic expression of a gene at a separate locus. A textbook example of this interaction involves the deposition of skin pigment in mice.
ANSWER: epistasis [or word forms like epistatic]
[10e] If mutations are additive and non-epistatic, they can cause direct evolution towards a single “peak” of this quantity on an adaptive landscape. Natural selection favors the survival of individuals with higher values for this measure of reproductive success.
ANSWER: fitness [prompt on W]
[10h] Population geneticists often contrast Sewall Wright’s adaptive landscape theory with this theorem developed by his rival, which states that the rate of increase of fitness of any species is equal to its genetic variance in fitness.
ANSWER: Fisher’s fundamental theorem of natural selection [prompt on Fisher’s theorem or fundamental theorem]
<Biology>