Researchers Find 'Junk DNA' May Have Triggered Key Evolutionary Changes in Human Thumb and Foot

[Celebration]

http://www.physorg.com/news139754828.html

Out of the 3 billion genetic letters that spell out the human genome, Yale scientists have found a handful that may have contributed to the evolutionary changes in human limbs that enabled us to manipulate tools and walk upright.


Results from a comparative analysis of the human, chimpanzee, rhesus macaque and other genomes reported in the journal Science suggest our evolution may have been driven not only by sequence changes in genes, but by changes in areas of the genome once thought of as "junk DNA."

........snip.........................

"Our study identifies a potential genetic contributor to fundamental morphological differences between humans and apes," said James Noonan, Assistant Professor of Genetics in the Yale University School of Medicine and the senior author of the study.

Researchers have long suspected changes in gene expression contributed to human evolution, but this had been difficult to study until recently because most of the sequences that control genes had not been identified. In the last several years, scientists have discovered that non-coding regions of the genome, far from being junk, contain thousands of regulatory elements that act as genetic "switches" to turn genes on or off.

An indication of their biological importance, many of these non-coding sequences have remained similar, or "conserved," even across distantly related vertebrate species such as chickens and humans. Recent functional studies suggest some of these "conserved non-coding sequences" control the genes that direct human development.