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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Recycled DNA = sloppy, reused code = spaghetti code = proof of FSM!
The link is made!
That hurts.
Obviously, you've never heard of Pak Protectors.
Elimination of the "goto" statement eliminated most spaghetti code. Whether this rendered the FSM dead or not...
Ante-pasta, VBasic, & 'shrooms placemark
But doesn't that just make 'goto' a transitional fossil?
I'm told the "goto" statement still exists in C++, but that it hasn't actually been observed. I would consider this more a case of cryptozoology.
Yes and no. Totally unused DNA would accumulate changes faster than DNA that was actually used for something (including both genes and non-coding promoter regions), so the greater difference in noncoding regions may just reveal that noncoding regions are mostly junk DNA (and research along other lines indicates that it is).
In order to conclude anything about whether the *significant* differences between human and chimp DNA (i.e., the DNA differences that actually make some kind of *actual* physical or behavioral difference between the species) are more in the genes or more in gene expression, you'd have to first specifically identify the promoter regions and then compare *those* against the coding regions of the genes.
And this is further complicated by the fact that some genes themselves act in the expression of other genes, etc.
If you take a bite out of that one, make sure not to look at what is likely to be wiggling inside of it.
(or so I've been told...)
Then you admit that C++ is a religion that requires enormous leaps of faith! Your 'science' of computers is nothing more than dogma for you neo-programmerists to keep the truth of Java from getting a fair chance!
(Added: I can't believe 'neo-programmerists' passed the spell checker.)
I know you're just being puckish, but since creationists often make a similar lame excuse for why the DNA of different species would have similarities, I'd like to point out for the lurkers that the specific *kinds* of characteristic similarities and differences found in DNA point unmistakably to evolutionary common ancestry, and *not* to "common design".
Furthermore, since we're using the programming analogy, it should also be pointed out that no one could possibly mistake the results of "evolutionary programming" (like genetic algorithms, etc., whereby evolution is harnessed to produce program code without direct human intervention or programming) for the results of a program written directly by a programmer (i.e. "designer"), even one which incorporated a lot of "code re-use" or cut-and-paste from other projects.
The results of the two methods of producing programs are *vastly* different in character and structure, and any programmer could tell at a glance whether a particular program was actually written by a human, or "grown/evolved" via genetic algorithms. And the same goes for DNA -- it looks exactly like the results of an evolutionary process, and not at all like the results of a "design team".
Just wait to see if yours gets deleted and if it does, re-ping.
Ah, but not all companies eliminated the "goto" statement. The last company that I worked for is still using Cobol and C. Subsequently, the FSM appears to be currently coexisting with the more "modern gods".
Puckish. Now there's a word I haven't heard in a long, long time.
BTW Nice picture
Wasson might say, "Soma of it".
Have you people never heard of the Universal Language, written by my uncle (that's the other one), known as FORTRAN? What kind of anti-science, Luddite, hippie-developed languages are used in industry today?!
Nurse, nurse, bring me my walker and my whacking stick! It's Whacking Day, I tell you!
I should have been more clear about what I meant. The article refers especially to changes in promoters (non-coding regions of the DNA) and I find that compelling.
According to Wasson, the plant is generally dried. It is also filtered through the kidneys of elk and cattle in some cultures (yes, that means just what it sounds like).
Wasson's theory was that soma in the Hindu pantheon was actually this mushroom; cattle being sacred follows along. Hence the name of his book (as Antonello astutely noted).
[Incidentally, I have a copy of the original numbered edition of 680. They are getting pretty hard to find nowadays.]
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