Send to

Choose Destination
Trends Ecol Evol. 1996 Jul;11(7):281-4.

Haldane's rule and its legacy: Why are there so many sterile males?

Author information

Dept of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.


A general pattern of animal hybridization, known as Haldane's rule, is that the XY (ZW) sex is more severely affected in its viability or fertility than the XX (ZZ) sex. Recent evidence suggests that three different forces have shaped this pattern: (1) the X chromosome and autosomes are in greater disharmony in the XY sex; (2) evolution of hybrid male sterility is greatly accelerated, at least in species with XY males; and (3) maternal-zygotic incompatibility preferentially affects the viability of the XX sex. In species with XY males, the rapid evolution toward hybrid male sterility may be responsible for the bulk of observations pertaining to Haldane's rule. One interesting and testable hypothesis is that sexual selection drives this rapid evolution.

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center