Author Topic: Research suggest that a LOSS of DNA lies behind our big brains  (Read 931 times)

lovemonkey

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Some very interesting stuff. If there's more to this then all creationists who insist that humans can't be the product of evolution simply because information in the genome can't be added should reconsider their argument. Things are not always what they seem at first. Full article can be found in the 9th of march issue of New Scientist.




http://www.sciencecodex.com/missing_dna_helps_make_us_human

http://www.newscientist.com/article/mg20928032.400-we-are-the-children-of-the-lost-dna.html

Extra genes did not make us human – it's what we lost that counts

AFTER 3.5 billion years of evolution, a creature emerged that could ponder its own origins and revel in a Mozart string quintet. Down the generations thousands of scientists and philosophers have either celebrated this uniqueness of ours or have denied it and sought the antecedents of everything human in other animals.

New insights into this debate have come from our DNA. In those heady days a decade ago when the first draft of the human genome was proudly displayed, the smart money was on "humanness" being found in genes themselves, the DNA that actually produces the proteins that make our bodies work. Intuitively, we've always assumed it must be something extra in our genes that gives us the edge.

It turns out that we were off beam. It quickly became clear that it is not primarily genes that make us different. Instead, so-called "regulatory regions" call most of the shots, even though they don't make proteins.

Secondly, and perhaps more surprisingly, it is now becoming clear that losing rather than gaining chunks of those regions accounts for some of our uniquely human traits. Altogether, we've "lost" 510 sizeable chunks of regulatory DNA, despite the fact that in other animals including chimps, mice and chickens, they're retained as indispensable (see "Key to humanity is in missing DNA").

This is not the first time that we have had to deal with the idea that the human genome is less complex than we thought. Before its sequence was published geneticists estimated we had around 100,000 genes. That figure has now plummeted to as few as 20,000.

What next? First and foremost, researchers should resist the temptation to engineer monkeys or chimps with "humanised" brains by deleting regions corresponding to those we have lost.

Ultimately, the great hope is that our missing DNA contains an answer to the profound question "what makes humans so different from other animals?" Only two of the regions have been studied in any detail: further experiments are under way to discover the impact of losing the other 508. But one thing is already clear: in human genetics, less is more.
from incomplete data