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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At least not knowingly.
0B35:0793 7403 JZ 0798 0B35:0795 E90700 JMP 079F 0B35:0798 8346D601 ADD WORD PTR [BP-2A],+01 0B35:079C E9A4FF JMP 0743 0B35:079F C45ED6 LES BX,[BP-2A] 0B35:07A2 26 ES: 0B35:07A3 8A07 MOV AL,[BX] 0B35:07A5 25FF00 AND AX,00FF 0B35:07A8 3D3000 CMP AX,0030 0B35:07AB 7D03 JGE 07B0 0B35:07AD E99400 JMP 0844 0B35:07B0 C45ED6 LES BX,[BP-2A]
Machine instruction aren't usually "structured".
And sometimes the screw-ups never go away either. Look at the FAA.
//Response to js1138
char Response()
if(poster="js1138")
{
printf("Go bonk yourself")
}
else
{
printf("I'm such a loser")
};
We did the same in early 1979. The LNW-80 clone came with the extra video memory and lower case enabled. What a breakthrough!
Whatever it is, machines like it.
You have an endless loop there at the end.
Yup. That's the joy of GOTO.
SUCK THE HUMOR?
hrmn... I see clearly you mean the aqueous humor, not the vitreous
Around here, yes. Also, I've somehow got two lines numbered 06. Program in haste, debug at leisure.
do the M98/M99 pocket-cycle instructions in ISO code count as "goto" instructions?
well, that is the distilled essence of Creationistic Evolution philosophy.
Really Slow Night in Dry Gulch placemarker.
really-stoked-that-my-handmade-yumi-WORKS placemarker
On the other hand, the infinite print loop appears to be a feature, not a bug.
Here's another possible candidate: Critique of “Intelligent Design” (ID)
Maybe that guy who babbles about his genius uncle will turn up.
OK, I liked C too, but IMHO for writing large complex programs correctly used C++, Java, or C# in particular has it beat by a long way.
My wife got tired of me hanging round the house a little while ago so I went out and got a job as development manager in a small software house. I can't say that the director who interviewed me didn't give me fair warning once I'd persuaded him that I wasn't after his job. What these guys have done (something like 40 developers) is written millions of lines of C, but using C++ syntax so they are under the illusion that they are writing in C++. #defines everywhere instead of inlines, no polymorphism at all, copious use of memset(0,sizeof) on pointers to class instances (which would of course break if they did go polymorphic), copy-and-paste used *every time* already developed stuff was needed elsewhere, presentation/business/data logic hopelessly mired in a single spaghetti tier. But hey! They'd got coding standards, "no gotos, lots of variable naming rules and only one return per function" (that last return rule some people like, but IMHO creates really ugly code). Some serious re-education is going on which is actually an interesting challenge. I'm trying to get the message through to the team-leaders that obeying a few rules about variable names and in-function code-structure doesn't make your code good.
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