Old men chasing young women: A good thing (from Science Blog)

It turns out that older men chasing younger women contributes to human longevity and the survival of the species, according to new findings by researchers at Stanford and the University of California-Santa Barbara. (老少配有助人類的繁衍耶)

"Rod Stewart and David Letterman having babies in their 50s and 60s provide no benefit for their personal survival, but the pattern [of reproducing at a later age] has an effect on the population as a whole," Puleston said. (雖然老來得子對於老先生本身並沒有太多好處，但是對於全人類卻是一大福音，哈哈，太妙了)

The scientists presented a "range of data showing that males much older than 50 years have substantial realized fertility through matings with younger females, a pattern that was likely typical among early humans." As a result, Puleston said, older male fertility helps to select against damaging cell mutations in humans who have passed the age of female menopause.(難怪有人說老男人生下的小孩會比較聰明，原來就是因為可能的基因突變已經被篩選掉了)

In the less developed, traditional societies, males were as much as 5-to-15 years older than their female partners.(傳統社會裡，就是喜歡男老女少配) In the United States and Europe, the age spread was about two years. "It's a universal pattern that in typical marriages men are older than women," Puleston said. "The age gaps vary by culture, but in every group we looked at men start [being reproductive] later. At the end of reproduction, male fertility rates taper off gradually, as opposed to the fairly sharp decline in female fertility by menopause." Despite small differences based on marriage traditions, all women and most men in the six groups stopped having children by their 50s, the researchers found. But some men, particularly high-status males, continued to reproduce into their 70s.(這是不是說，社會地位越高的人，越想要生小孩?) The paper noted that the age gap is most pronounced in societies that favor polygyny, where a man takes several wives, and in gerontocracies, where older men monopolize access to reproductive women. The authors also cite genetic and anthropological evidence that early humans were probably polygynous as well.

Grants from the U.S. National Institute on Aging supported this study