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
I agree, you can believe in evolution and still be a christian and creationist.
It's the timeframe, but I also don't believe the bible speaks to anyone. I believe that people read the bible, and interpret it, and love the words that are contained in it. I believe that some people follow the teachings that are in the bible and are drawn closer to God by his word.
To other scientists.
True. I have a "beneficial mutation" for modern life.
So, let's see, you don't want to teach the science of evolution because you find Darwin's views on race and sex to be offense? Nice ad hominem attack. Don't teach the science of evolution in schools because English society during the Victorian Era held distasteful views on women and black people--your powers of reasoning are breathtaking.
Marvin Lubenow is not a "Darwinist/macroevolutionist". He is a creationist. It shows the absolute bankruptcy of your position that you have to lie about him to support your ridiculous argument. Who are you going to cite next, the famed evolutionary biologist Duane Gish??
"... every Darwinist does argue from an unproven and unprovable premise: that something can come out of nothing.
Wrong. Typical ill-informed creationist crap. Evolution doesn't require "something from nothing". It is about descent with modification. Even abiogenesis doesn't require "something from nothing".
That takes "Darwinianism" out of the realm of science and into the realm of blind faith religion. If you want to have a theological debate, that's one thing. But don't assert that evolution is factually correct ...and don't force the state to spread that doctrine in schools.
Again, you are talking out of your ass. The science of evolution is based on the millions of data points that support the theory. That is not science, not religion.
And the creationist tactic to assert that evolution and creationism are equally scientific or equally religious is as tiresome as it is mendacious.
Religion is when you reject the scientific data, or make meaningless distinctions like "macroevolution" and "microevolution", or waste your time arguing between the mutually ridiculous contentions such as "young earth" versus "old earth", all because you think your faith is threatened by evolution.
Nightmares tonight
Your empty Christian hating faith will bring you nothing, ever
Amen, d'ed. And Happy New Year, by the grace of God alone.
"These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world." -- John 16:33.
Amazing how many cheerful Christians there are in the world among the puckered, dissolute and bitter masses.
We advance by God's will alone.
I only play with the unserious one-armed boat rowers for so long and then it gets boring going in circles.
Hey!
You ain't the guy on WKRP who thought turkeys could FLY are you????
But.. it ain't whether you win or lose; but how you play the game that counts.
ternal????
E-ternal
You make such profound statements. LOL
bump!
Moses was divinely inspired. The concepts/laws/ideas given to him were the major catalysing force of human history.
Now that makes quite a bit of sense to me and can understand it to be true.
Now will come the Flood of Hammiburi (SP?) stuff that came BEFORE Moses, etal.
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