Inbreeding hurts the next generation’s reproductive success
Preliminary data tally birth stats of kids with closely related parents
ORLANDO, Fla. — Kissing cousins aren’t doing their children any evolutionary favors, some preliminary data suggest.
Mating with a close relative, known as inbreeding, reduces nonhuman animals’ evolutionary fitness — measured by the ability to produce offspring. Inbreeding, it turns out, also puts a hit on humans’ reproductive success, David Clark of the University of Edinburgh reported October 20 at the annual meeting of the American Society of Human Genetics.
Offspring of second cousins or closer relatives make up about 10 percent of the world population, Clark said. He and colleagues collected data on more than a million people from more than 100 culturally diverse populations and calculated the effect inbreeding has on traits related to evolutionary fitness.