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
It would not affect my faith but if the foundation of your belief is that the Bible is literally true, it would upset your faith in the Bible.
Boy, are you going to be surprised when you meet King Osiris in the afterlife....
Well, the latter part of that period gave us the first representative fossils of almost all major animal divisions (I forget, are those families, or phyla, or what?), and yet we have absolutely NO fossils representing evolutionary forms of animals between those major groups. Evidence for macroevolution (between major classes of animals)? There just isn't any.
I've read a good bit on it, but I'm no expert and I don't have any emotional commitment to answering the question one way or another. But, I will say to those who see man as a natural evolution from the animal world, that I'll start thinking there may be something to it when some species other than man, ANY species, writes a novel, builds a monument, or splits the atom (I figure that if any species other than ours splits the atom, it will be the house cats, and when they do, we're ALL in trouble. ;)) I mean, haven't the animals had even longer to evolve than we have? What's up with that? To my eyes they all seem just stuck, spinning their wheels. You would think that by now there would have arisen another intelligent species to challenge and compete with us.
Take care-- like I said, I'm not an expert, and I really AM bowing out of this discussion now. These discussions NEVER prosper, which is a sure sign to me that evolution really is just as much as religious belief as any belief in any god.
Yawn.
Who gets in and who doesn't. You mean that no one is in heaven yet?
You do realize that the 6000 year old Earth is based solely on man's (fallible) interpretation of the Bible, right?
Were they more physically capable? Most likely. Today, through the use of our minds we no longer have to use stone tools, sticks, and bare hands for all of lifes needs.
Fossile evidence shows that from the time man 'discovered' he could sharpen a rock to make a crude knife/blade with it it took thousands more years for man to 'discover' that he could make far greater use of it by putting it on the end of a stick.
Just my way of poking the high and mighties and reminding them that though they think it the case, they might be rejected when the time comes.
Yes, obviously if you believe the Bible is 100% literal, than anything that says Adam and all the animals that ever were were simply poofed into existence and brought to Adam for naming, and then God took his rib to make him a wife, then yea, Evolution doesn't really jive with that.
Of course if you believe the Bible is at all times 100% literal, basically the fossile record destroys this notion with or without evolution... as Millions of animals existed long before man walked the earth, so it would have been impossible for Adam to have been brought all of them for naming.
Like I said, only Atheists and Radical Fundamentalists are the ones that argue that evolution is in conflict with God.
Remember, Science at its BEST can only answer "HOW" God works or has worked in the Universe, it does not answer, and can never answer "WHY". Spirituality is about WHY... Science is about HOW.
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, as the following quote from one of his posts on this thread demonstrates:
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.
Presumably, Matchett-PI would also concur with the idea that there is enough sloppiness in Genesis to accomodate evolution as well.
And if you do accept Jesus as the son of God and the saviour how can you be jewish?
I'm speaking of being Jewish as being a member of the Jewish race. If you practice the Jewish religion, however, without accepting Christ, then yes, there's obviously a conflict.
MM
You don't have to read the whole thing. Just start with the Books of Matthew and John from The New Testament. You will get more answers than you can ever imagine.
There is, of course, no evidence for this belief whatsoever.
I'll let my wife and her family know that FReeper MississippiMan has informed me that they are all going to hell. I am sure they will be most appreciative of the news.
Of course, unless your Mormon you are going to hell too. South Park said so.
It is hard to the show evolutionary tree of a non-existant animal. What, exactly, is your point?
There is no such thing as a Jewish race, anymore than there is a Protestant race.
Well, they do appear for all intensive purposes to be "rush jobs"...
C'mon....lighten up. I was just kidding around.
I believe some call it the Law of Retrospective Astonishment.
Walden,
Believe me I am no expert, and I don't subscribe to the Evolutionary theory as "god" group myself. It has issues, that one day may or may not be resolved.
The point I am trying to make though is to those who dismiss it out of spirituality concerns. Even if Macro Evolution were shown to be 100% correct, this would not remotely invalidate God.
Hell even if the String theorists are correct, and we live on a membrane surrounded by other membranes and it was the collision of our membrane with another membrane that released the energy that created our universe... St Thomas Acquinas arguments for the existence of God still hold true.
After all, for change to happen, something must have instigated the first change... for things to exist, something prior to it must exist to create it... You take both of these statements back to their ultimate beginning and you are left with SOMETHING out of NOTHING... And that something that willed something from nothing is God.
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