Skip to comments.Researchers Uncover Brain Patterns That Differentiate Humans From Chimpanzees
Posted on 04/11/2002 3:27:46 PM PDT by Nebullis
A team of international researchers from Germany, the Netherlands and San Diego may have shed light on why chimps and humans are so genetically similar (nearly 99 percent of shared DNA sequences), and yet so mentally different.
In a study published in the April 12, 2002 issue of the journal Science, the scientists noted that the striking difference between these primate cousins is most evident in their brains. The disparity appears to be the result of evolutionary differences in gene and protein expression, the manner in which coded information in genes is activated in the brain, then converted into proteins that carry out many cellular functions.
The brain differences are more a matter of quantity than quality. Differences in the amount of gene and protein expression, rather than differences in the structure of the genes or proteins themselves, distinguish the two species.
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Oh come on now, the argument would be made that this is evidence of the common ancestry of chimp and man and is conclusive evidence of Darwinian evolution.
"They found five times as many changes in gene expression -- actual activity by the genes -- in the human brain than would be predicted by evolution.
"If two species have been apart for 5 million years, you expect a certain amount of differences," Varki said. But there are many more differences in the human brain than expected. "Whereas if you look at liver and blood, you don't see that," Varki added
There are direct quotations. Apparently the writer has has at least listened to the researchers.
I don't see how the text of the article is much different than your statements that "when human and chimp DNA is compared and average rates for genetic differences are calculated, a genetic evolutionary speed is inferred. But the cognitive difference between humans and chimps is greater than this genetic difference would imply." How is that much different than saying that they found many more differences in the human brain than they expected? And why did they expect certain results? They were expecting different results because they were inferring a "genetic evolutionary speed", as you correctly point out.
There's still an enormous gap in understanding of expression from gene sequence, especially in multicelled organisms. At each major level, starting with transcription through RNA processing, through translation and post-translational processing, there is an amplification of possibilities, cascading of effects, networked feedback loops, and so forth. You can see how this becomes complicated very quickly and how it's difficult to tease out one aspect of it.
Identical sequences end up affected differently in different cell types. The brain expresses different proteins than the liver. We already know about the differences between different cell types. This study shows that there is a species expression difference between same cell type.
All this can't be separated from development. The signals at the unicellular stage start the program of expression patters with morphogenic gradient fields.
A fascinating book is Calvin's Throwing Madonna
The idea is that our ancestors adopted throwing stones to hunt for food. In order to get accuracy it is necessary to release the stone at a precise time. This requires lots of neurons working together. Hence our large brains. He also discusses handedness.
That this might happen over millions of years seems plausible to me and best supported by the evidence. I've heard all the Creationists' arguments against evolution and I'm not impressed. That said, I will remain open to any realistic possibility for what brought the singular miracle of humanity into the world.
We Creationists are winning that one too.
Of course we are. Only a total ideologue without a scientific bone in his body like Darwin could have said that the difference between man and monkey is one only of degree. Unfortunately, many much smarter people, who know much better, such as those who made this research, are forced to prostitute themselves and their research and bend their knee to evolution. The source of the difference is beyond explanation, the speed of the differences arising is unexplainable also. The process is tremendously complex and certainly not subject to "random" origination. In addition, if the Darwinian god "selection" were the cause of this, why did not monkeys select for intelligence also?
And why did not monkeys learn the same way? Evolutionists really are grasping at straws when it comes to explain man. Let me ask you this one, what is the necessity of art? How come man is the only species that does art? Let's also note that art has been found from the earliest traces of homo sapiens in the caves of Southern France and Northern Spain.
Do you mean realistic or materialistic? It is two different things. The argument of necessity is totally bogus. Since supposedly both humans and monkeys arose from the same ancestry, why did not the same necessities operate on both? Further, the differences between the abilities of man and monkeys are huge in spite of the small genetic differences. The question that evolutionists need to answer is not whether there are material differences between man and other species, but how those differences could have arisen. This paper makes answering the question even more difficult.
But, we've known this for quite sometime. Haven't you seen 2001 A Space Odyssey or The History of the World: Part I ?
But more seriouly the debate about the difference between humans and animals hasn't changed much, nor have we progressed much in understanding it. But it makes for a very interesting study.
The first modern scientist, Aristotle, in various of his works points out at least three distinguishing characteristics between humans and other animals. He calls humans variously the political animal (perhaps city-dwelling animal would be a better translation since the word political has gained so much baggage over the years), the animal having reason (echon logon), and the imitative or image-making animal. This last distinction is quite interesting in the field of paleontology. Chesterton once pointed out that when the first caves of Neanderthal man were discovered (I believe in France), everyone immediately assumed that the drawings on the cave walls depicting some ancient deer were drawn not by a deer but by a man. Images are the signposts of man. Moreover, he continued, it is noteworthy that few scientists think that those drawings were made by a child in play or were the work of an ancient artist. Paleontologists assume that ancient man was a more like a beast than a man even though he alone of the prehistoric animals makes signs, the marks of man alone.
The inherent relationship among these three distinguishing aspects of humans is also very interesting. In Greek the word logos means speach, reason, word, and even thought. The relationship between speech and thought and their relationship to the world is also very fascinating. Is the word an image of the things, or the things an image of ideas? A debate we have left to collect dust on the bookshelves in the writings of the ancients and medievals, testimonies of ages past when correct reasoning was thought an art of most worthy pursuit, having ourselves advanced to the art of brain picking, literally. But to continue, in Greek the word for image or look (eidos -- whence our word idol, which means image) is the the root for the word idea (idea). In any case, these three distinguishing characteristics of man, viz. the political, the having speech/reason, and the imitative animal, are very closely linked. For speech is an image of things or visa versa, we only learn and develop speech and thought from others in the home and society, and society is an image of certain reasonings or speech, esp. speech concerning what is right and wrong.
In any case, just thought I'ld contribute to, in the words of Walker Percy, symbol-mongering.
I've read the arguments on all sides. I've argued extensively and very civilly, primarily with "Creationists" within my own family, always qualifying that I don't know the answers. Aside from making unsupportable by basic standards and strained, to say the least, conclusions purely on the basis of faith, the Creationist argument for the age of the Earth and a world-encompassing flood about four thousand years ago, our God-given logic strongly suggests otherwise. The Bible may be all it's stacked up to be, but I highly doubt it is if it was meant to be interpreted literally.
It sounds to me that you are rejecting more than just an absolute literal interpretation of the Bible. You seem to be rejecting the whole point of the Bible, the spiritual point. The point that man is a special creation of God and has a special relationship with God. This point is completely inimical to the materialism of evolution. Also, let me point out that as far as I know there is no such Christian denomination as "Creationists". That is a name invented by evolutionists to bash Christians without mentioning the word Christian.
The obvious answer is that our ancestors took to the plains and savanahs, and the other apes' [not monkeys, the ape-monkey split predates the ape-human split] ancestors stayed in the jungle.
Evolutionists really are grasping at straws when it comes to explain man.
Explain what you mean here. Have you ever read The Descent of Woman by Elaine Morgan? It is speculation (scientific speculation, based on facts of anatomy and behavior) that some of our ancestors were semi-aquatic. Fascinating.