Question

Which of the following hypothetical observations is in line with Haldane's rule?

	a.	Hybrid survival rates are lower than survival rates in the parental species
	b.	Most offspring from interspecific matings in mammals tend to be female
	c.	Offspring resulting from interspecific matings are sterile
	d.	Individuals avoid mating with heterospecifics
	e.	Closely related species diverge in their phenotypes where their distributions overlap

Answer 1

Haldane's Rule : In 1922 , J.B.S Haldane stated that, if one of the species which participate in hybridization are inviable or sterile, the afflicted species is much more likely be heterogamous (XY) rather than homozygous ( XX ) .

The Heterozygous species is more likely to be absent, sterile or rare relative to the homozygous species in the offsprings. Halden's rule is seen regardless of species heterozygosity and is seen in numerous animal taxa of insects, mammals, birds and reptiles.

Hence from the above question the hypothetical observation in line with Halden's rule is option C.