Early humans, chimps were kissing cousins, gene study suggests
Last Updated Wed, 17 May 2006 22:25:06 EDT
CBC News
Early human ancestors interbred with chimpanzees after the two species split, researchers propose.
The break from our chimpanzee cousins was messier, more recent, and occurred over a longer timescale than thought, according to a new genetic analysis.
"The genome analysis revealed big surprises, with major implications for human evolution," said study co-author Eric Lander, director of the Broad Institute of Harvard and the Massachusetts Institute of Technology.
Scientists had thought humans and chimps shared a common ancestor, but split about 6.5 million to 7.4 million years ago.
Previous research on the split of the species focused on average genetic differences.
Lander and his colleagues took advantage of the full genetic codes of humans and chimpanzees to estimate the age of sequences, rather than relying on an average.
'Evolutionary smoking gun'
If early humans and chimps separated, interbred and then parted ways again, it would explain the young nature of the human X chromosome.
"[T]he speciation itself occurred in an unusual manner that left a striking impact across chromosome X," Lander said in a release.
"The young age of chromosome X is an evolutionary 'smoking gun.'"
The two species split no more than 6.3 million years ago and probably no more than 5.4 million years ago, the team said in Thursday's issue of the journal Nature. That's one to two million years more recent than previous estimates.
The team plans to use the complete genome sequence of the gorilla and other primates to refine their timeline of when humans and chimps became separate species.
7 comments:
I have kissed a few chimps, and more than a few "evolutionary smoking guns". Current beloved not included in the preceding self-slur.
Jon's not hairy enough to be classified as simian, especially with the road rash.
Even if he WERE alarmingly hirsute, being a cyclist, he's alarmingly hair-free. Like one of those fucked-up unpettable cats, except he's not wrinkly and he doesn't shit in a box. And, I rather like the exceedingly well-groomed character trait.
What's up with the cycling obsession + hairlessness thing, anyway? His answers to this question leave me dissatisfied.
HAHAHAHA, burn marks like Jon's current ones?
Shaved/waxed legs facilitate:
1. cleaning injuries/road rash (ask Jon) - much easier and less painful without hair to contend with.
2. deep tissue massages (ever tried to get a sport massage with hairy legs? Ouch.)
3. comfort in lycra shorts/suits (I can defend that one. Matted hair under sweaty shorts for hours on end is NOT comfortable)
4. Ego/intimidation? Shaved/waxed body parts make muscles, etc look bigger, and make the wearer look more Euro and awesome than they most likely are.
5. Any others?
Shaving & waxing = better than burning.
Yes, next time I will remove my hair and not my skin. I got a little aggressive with the treatment.
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