Posted on 12/29/2004 9:14:28 AM PST by aculeus
Emergence of society may have spurred growth
The sophistication of the human brain is not simply the result of steady evolution, according to new research. Instead, humans are truly privileged animals with brains that have developed in a type of extraordinarily fast evolution that is unique to the species.
"Simply put, evolution has been working very hard to produce us humans," said Bruce Lahn, an assistant professor of human genetics at the University of Chicago and an investigator at the Howard Hughes Medical Institute.
"Our study offers the first genetic evidence that humans occupy a unique position in the tree of life."
Professor Lahn's research, published this week in the journal Cell, suggests that humans evolved their cognitive abilities not owing to a few sporadic and accidental genetic mutations - as is the usual way with traits in living things - but rather from an enormous number of mutations in a short period of time, acquired though an intense selection process favouring complex cognitive abilities.
Evolutionary biologists generally argue that humans have evolved in much the same way as all other life on Earth. Mutations in genes from one generation to the next sometimes give rise to new adaptations to a creature's environment.
Those best adapted to their environment are more likely to survive and pass on their genes to the next generation.
The evolution of a large brain in humans, then, can be seen as similar to the process that leads to longer tusks or bigger antlers. In general terms, and after scaling for body size, brains get bigger and more complex as animals get bigger.
But with humans, the relative size of the brain does not fit the trend - our brains are disproportionately big, much bigger even than the brains of other non-human primates, including our closest relatives, chimpanzees.
Prof Lahn's team examined the DNA of 214 genes involved in brain development in humans, macaques, rats and mice.
By comparing mutations that had no effect on the function of the genes with those mutations that did, they came up with a measure of the pressure of natural selection on those genes.
The scientists found that the human brain's genes had gone through an intense amount of evolution in a short amount of time - a process that far outstripped the evolution of the genes of other animals.
"We've proven that there is a big distinction," Prof Lahn said. "Human evolution is, in fact, a privileged process because it involves a large number of mutations in a large number of genes.
"To accomplish so much in so little evolutionary time - a few tens of millions of years - requires a selective process that is perhaps categorically different from the typical processes of acquiring new biological traits."
As for how all of this happened, the professor suggests that the development of human society may be the reason.
In an increasingly social environment, greater cognitive abilities probably became more of an advantage.
"As humans become more social, differences in intelligence will translate into much greater differences in fitness, because you can manipulate your social structure to your advantage," he said.
"Even devoid of the social context, as humans become more intelligent, it might create a situation where being a little smarter matters a lot.
"The making of the large human brain is not just the neurological equivalent of making a large antler. Rather, it required a level of selection that's unprecedented."
Guardian Unlimited © Guardian Newspapers Limited 2004
Good queation, and I'm sure that anyGoogling of JewsforJesus or messianic Jews will give better answers than the current group on this thread....
Current events ... I just knew you weren't born yesterday.
You bet. Hopefully, nobody minds our little digression. ;o)
Is there a specific reference that you base the single-coming belief on, or is based on an absence of specific reference to multiple "comings?" Hope that makes sense, LOL.
It makes sense. I understand why Christians believe in the 'second coming', because it is prophecied in their scriptures. But there is no prophecy of a 'second coming' of mashiach in the Hebrew scriptures. (There are, additionally, substantial theological differences between the Jewish and the Christian concepts of "messiah").
Please see my subsequent post.
"What an odd statement for an evolutionary biologist. Should "evolution" be capitalized?"
I noticed this too .... the fact is that he was being honest within the context of his quote. There is a great 'faith' out there in 'science' as an entity. He's not really a 'evolutionary biologist'; he's a priest of secularism disguised as a kindly lab coated dude in an unbiased search of, ahem deep breath now, the 'truth'. Ah we are so fortunate...
You do that. They probably don't know that a Jewish prophet was the one who started that whole line of thought.
Why do I say this?
Because somehow, your 'Jewish' wife managed to marry outside of her 'religion', like so MANY do today.
Does that mean that Muslims will also get to Heaven?
atlaw: "Not according to Matchett-PI, since his contention is that there is enough sloppiness in Genesis to accomodate both an old earth and a recently created earth. ..Presumably, Matchett-PI would also concur with the idea that there is enough sloppiness in Genesis to accomodate evolution as well."
[1]There is no "sloppiness" in Scripture. I didn't use that word, and am curious as to your motivation for wanting to change the meaning of what I wrote. Was it deliberate, or just done out of an honest misunderstanding due to a lack of careful reading?
[2] See #196.
Isn't it funny, too, when some crature that was thought to be extinct for 200 million years is caught in a fisherman's net that suddenly it becomes a "living fossil"? Also, notice how only SOME animals "evolve".
"Liberal women have small brains. Conservative men have big ones. Whether we use them is an application mystery."
What is not as well known is that the hemispheres of the female brain are usually of nearly equal weight. In men, however, the left hemisphere is usually 20 percent heavier than the right. Now the REAL question is what is the weight difference, if any b/t the demo and repub male brains....
Exposure to the big T is the culprit. Interesting in a manly kind of way, heh heh ....
I am assuming that you know full well that the theory of evolution predicts the existence of no such fossils, and indeed, if such fossils were found, the notion of special creation would be profoundly advanced.
Yet you argue that the theory of evolution is falsified by the nonexistence of these fossils.
Now go back to my questions. What is the goal of this deliberately false assertion? Do you advocate making such false assertions to students? And how do you reconcile Biblical admonitions against dishonesty with the deliberate dissemination of falsehoods to unsuspecting students?
I did; thanks!
MARK to read later
Do THEY fulfil all the things in THEIR book?
An example I like is the idea that the entire period since the birth of Christ could be represented by 20 people in a room having bagels and coffee. Most of them would have to be resurrected, of course, but consider that if teaching was word of mouth only, and if each person lived 110 years, not impossible, and passed his word of wisdom at age 105 to a five year old, and this continued through the centuries, those 20 would suffice to pass the word directly. All the way back to 6000 BC [pretty much the oldest historical stuff] would be represented by 80 people, still few enough to fit in a small lecture hall or a medium commuter jet.
You guys need to talk.....
I was referring to those that do. I have everything in MY book covered. I am happy.
Asserting creation is NOT a deliberate false assertion!
>evolution predicts the existence of no such fossils<
Then I assume you can explain WHY evolution should be believed without this evidence?
Because it a story meant to teach a moral lesson. Not a recounting of history. And in many ways, it is not even a very good story. The forbidden fruit was the knowledge between good and evil - what parent doesn't want their child to know the difference between right and wrong?
To sit here and say we know what happened and what is happening because we have made a few scientific discoveries or have discovered some writings called the Bible in the Middle East is to state you are very arrogant, either way.
We don't know and we will never know because regardless of our ability to recognize our version of time and space it doesn't translate into knowing the answer to everything.
We have 5 senses that evolved to provide us with survivability; to extend those 5 senses into demigod like abilities is sheer nonsense and arrogance.
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