Friday, January 30, 2009

In praise of (dirty) old men.

This article (of which I have only read the abstract) solves a theoretical problem in evolutionary biology by explaining how continued male fertility after the age of female menopause can explain the lack of a "wall of death" after that age. Though I guess my thought is that it really only explains the absence of such a wall for men, not women, and it treats the age of menopause as exogenous, which maybe you do not want to do. You can, of course, get the women to old age by positing some survival value to having the mother around to care for children born just before the onset of menopause.

Key bit:

Thus old-age male fertility provides a selective force against autosomal deleterious mutations at ages far past female menopause with no sharp upper age limit, eliminating the wall of death. Our findings illustrate the evolutionary importance of males and mating preferences, and show that one-sex demographic models are insufficient to describe the forces that shape human senescence.

I do find it odd, as well, that these models would not routinely include separate behavior for men and women.

Hat tip: Charlie Brown