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
"Too often young earth proponents have failed to distinguish scientific arguments for creation by design from scientific arguments for a young earth, and have therefore prevented old earth advocates from joining them in a battle for the minds of an unbelieving scientific community.
Moreover, young earth proponents have sometimes failed to recognize that scientific arguments for a young earth (which seem to them to be very persuasive) are not nearly as strong as the overwhelming scientific arguments for creation by intelligent design.
As a result, young earth proponents have too often given the impression that the only true "creationists" are those who believe not only in creation by God, but also in a young earth. ....
It is likely that scientific research in the next ten or twenty years will tip the weight of evidence decisively toward either a young earth or an old earth view, and the weight of Christian scholarly opinion (from both biblical scholars and scientists) will begin to shift decisively in one direction or another.
This should not cause alarm to advocates of either position, because the truthfulmess of Scripture is not threatened our interpretations of Genesis 1 have enough uncertainty that either position is possible). Both sides need to grow in the knowledge of the truth, even if this means abandoning a long-held position." [Wayne Grudem pages 307-309 Systematic Theology - An Introduction to Bible Doctrine - 1994-Zondervan Grand Rapids,Michigan]
Ask him/her about electrons - or how, for that matter, we came to develop the periodic table of the elements (IOW, start with something easy first).
The human brain is almost certainly the result of sexual selection. Once you have an organized society, wealth can be achieved by brainpower more than by muscle. And it is wealth that attracts the women.
See #81
There are many, but the main four are: world peace, the return of all the Jews to Israel, the rebuilding of the temple, and universal knowledge of God.
But you have to rely on the word of man to tell you that it is the word of God.
But what I meant by transitory fossils are ones where, the transition from reptilian to avian or some other such transition.
I can think of some reasons this would be possible, but being Jewish is not one of them.
Yes. But since you brought up the subject in general terms, I assumed that you already knew the difference and merely asked you to be specific. If indeed you don't know the difference, that can be your research assignment for the day and if you like, you can report back here as to what you learned.
Do you honestly believe that the earth is only 6,000 years old?
>>>The Word of God ... nothing is more reliable or more true.
So does the word of God say that I shall not kill (KJV) or does it say I shall not murder (NIV)? Both are purported to be the Word of God, but both have very different impacts on acceptable behavior.
The transition has been bolstered with recent fossil finds showing feathered "lizards".
The world was created on August 9, 1974.
(Being the oldest specific date I can remember, seeing the headline Nixon Resigns on the front page of the newspaper).
I agree with you but I remember a 20/20 or Dateline or some other such program about the issue of short men.
They had women select men through a one way glass and the women ALWAYS went with the taller man even if he was unemployed/"underemployed" or undereducated. The short men were even built up to be wealthy, educated, etc. but they still lost out to the tall guys.
There just seems to be something hardwired into women to not select guys they have to look down on, literally that is.
I'm not sure what "macro evolution" is. So you you're saying that individual mammals - dogs, cats, weasels, opposums, humans, can evolve from a common mammalian ancestor, and same for birds and reptiles and whatnot, but individual classes can not?
Ever hear the true axiom, "Ignorance can be cured with education, but stupid is forever."
I'll give you the benefit of the doubt.
I know lots of people that never "confessed" to the Lord.
No one that believes the earth is 6000 years old has any reason to call another "stupid".
This is truly laugh out loud funny. I guess it's waaay to easy to credit God. Instead they have to come up with superfast evolution and evolution-with-a-purpose...
Hmm I suppose that would explain the The One-Eyed One-Horned Flying Purple People Eater.
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