Posted on 11/15/2005 8:25:44 AM PST by balrog666
'Perception' gene tracked humanity's evolution, scientists say
A gene thought to influence perception and susceptibility to drug dependence is expressed more readily in human beings than in other primates, and this difference coincides with the evolution of our species, say scientists at Indiana University Bloomington and three other academic institutions. Their report appears in the December issue of Public Library of Science Biology.
The gene encodes prodynorphin, an opium-like protein implicated in the anticipation and experience of pain, social attachment and bonding, as well as learning and memory.
"Humans have the ability to turn on this gene more easily and more intensely than other primates," said IU Bloomington computational biologist Matthew Hahn, who did the brunt of the population genetics work for the paper. "Given its function, we believe regulation of this gene was likely important in the evolution of modern humans' mental capacity."
Prodynorphin is a precursor molecule of the neurotransmitters alpha-endorphin, dynorphin A, and dynorphin B, collectively called opioids because their action is similar to stimulatory effects caused by the drug opium.
The notion that humans are more perceptive than other primates would hardly be news. But the list of genes known to have tracked or guided humanity's separation from the other apes is a short one. Genes controlling the development of the brain almost always turn out to be identical or nearly so in chimpanzees and human beings. And as it turns out, the protein prodynorphin is identical in humans and chimps.
It's the prodynorphin gene's promoter sequence -- upstream DNA that controls how much of the protein is expressed -- where the big differences are. "Only about 1 to 1.5 percent of our DNA differs from chimpanzees," Hahn said. "We found that in a stretch of DNA about 68 base pairs in length upstream of prodynorphin, 10 percent of the sequence was different between us and chimps."
Hahn said this "evolutionary burst" is responsible for differences in gene expression rates. When induced, the human prodynorphin gene was 20 percent more active than the chimpanzee prodynorphin gene. Past research has also observed variation in expression levels within humans.
This report supports a growing consensus among evolutionary anthropologists that hominid divergence from the other great apes was fueled not by the origin of new genes, but by the quickening (or slowing) of the expression of existing genes.
Hahn and his colleagues at Duke University, University College London and Medical University of Vienna first became interested in primate prodynorphin after noticing an unusual amount of variation in the human version's promoter. The scientists decided to examine the prodynorphin gene in human beings around the world and in non-human primates to see whether such variation was commonplace and whether that variation affected gene expression.
The group found a surprisingly large amount of genetic variation among humans within the prodynorphin gene's promoter. They examined prodynorphin genes from Chinese, Papua New Guineans, (Asian) Indians, Ethiopians, Cameroonians, Austrians and Italians.
The group also sequenced and cloned prodynorphin genes from chimpanzees, gorillas, orangutans, rhesus macaques, pigtail macaques and guinea baboons. The researchers found that high genetic variation in the prodynorphin promoter was unique to humans. Other primates' promoters were far more homogeneous.
Exactly how prodynorphin influences human perception is unknown. Evidence for its various effects comes entirely from clinical studies of people who have mutations in the gene. Past clinical studies have also indicated a positive correlation between lower prodynorphin levels in the brain and susceptibility to cocaine dependence.
Matthew Rockman, David Goldstein and Gregory Wray (Duke University); Nicole Soranzo (University College London); and Fritz Zimprich (Medical University of Vienna) also contributed to the research. It was funded by grants from the National Science Foundation, NASA, the Royal Society, and the Leverhulme Trust (U.K.).
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"It also supports the idea of outside manipulation. This is a good case for ID.
The Bible described this over 2,000 years ago, long before man created science"
If ID is what happened and the vehicle that caused it was the Biblical God, then how is ID different than creationism?
Everything is a good case for ID. That's the problem.
Because we're not going to *call* it "creationism"
It only fits in Creationism if you're willing to admit that chimps and humans share a common ancestor. So I guess that makes you an evolutionist. Welcome aboard the bandwagon.
And even anything that can't.
I can't see that.
Exactly. Thus, Goddidit.
Sorry. I thought I asked Admin Mod to delete this one.
I'm just here for the party. Don't much matter to me which bar it's in. ;-)
Indeed. And wherever there's a party there has to be a drunken lout making an ass of himself. I can't shirk that duty.
They were only fake pearls, anyway.
I guess all we need now is a barfly - any takers?
How?
Specifically, how does the similarity of DNA support the idea of outside manipulation more than it does a common ancestor?
Anyone who has programmed for a living knows that budget constraints and managerial incompetence often result in the reuse of bad code, and the accumulation of dead code. Looks like a designer to me. More likely a team of Microsoft programmers.
Do tell. What leads you to emit this bizarre statement?
LOL!
It's not often that a creationist cites sloppy design as proof of God....
Anyone who has programmed for a living knows that budget constraints and managerial incompetence often result in the reuse of bad code, and the accumulation of dead code.
This brings back many bad memories. Like having to completely rewrite such code (hundreds of thousands of lines) and preserve all functionality plus provide new functionality, and when all done, because of 'budget constraints and managerial incompetence', we're back where we started from.
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