8/06/2013

Headline, August07, 2013


'''WHAT MAKES HUMANS HUMAN : 

THE SCIENTIFIC MYSTERY'''




People have always wondered why ''humans'' are so special as a species. Six million years ago, humans and chimps were one species. Yet for some reason they diverged. Chimps pretty much stayed chimps. Yet the human brain exploded in both size and complexity.

Bruce Lahn is a Professor of Genetics at the University of Chicago. Some over 16 years ago, he helped map the human Y chromosome, a discovery that did lead the to male birth control. He then got set to solve an even greater mystery:  What makes humans ''human''.
Here is this great native of China, who as a college student led pro democracy rallies in Beijing in the 80s, explain the roam and the brilliance in his very own words:

''Our Labs first major discovery about a year ago, was that the human brain had evolved much more rapidly and from many more gene mutations than was once thought. This implied that the selection for a better brain must have been very intense during human evolution. We decided to track down and study some of the genes that might have contributed to the accelerated evolution.

We eventually honed in on ''ASPM and microcephalin'' two genes that are critical regulators of brain size during development. We conducted two extensive studies of the genes using subjects representing all the major indigenous populations of the world. By analyzing the slight differences in the genes among many, many people, we were able to deduce how they evolved over time and trace them back to their original copies.

More, we found that in each of these two genes there is a new mutational variant that emerged and spread in the very recent past of human history, because it confers a strong fitness advantage. In effect, we caught the evolutionary process in action. For microcephalin, the new variant is present in higher frequency in people outside of Africa   -where modern human first appeared-  as compared with Africans. 
For ASPM, the new variant has higher frequency in Europe and the Middle East than in other parts of the world.

Perhaps most remarkable is how young these new mutational variants were in evolutionary terms. The new variant in microcephalin can be traced to a single genetic copy in one human just 37,000 years ago. This is 160,000 years after humans as a species first arrived on this planet. And from that single copy, 70%  of world population now have the variant. The case of ASPM is even more extraordinary. The new variant first appeared  fifty-eight hundred years ago and has since risen from a single copy to about 30% of world populations today.

This unique and amazing scientific post continues. Don't miss the next one.
And This whole idea may be the most Impolitic idea of the Year!
So are some people Evolved than the others??!!

With respectful dedication to all  the Students, Professors, and Teachers from Morocco! See ya all on the World Students Society Computers-Internet-Wireless : ''Triumph Over Problems''.

Good Night & God Bless!

SAM Daily Times - the Voice of the Voiceless

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