Saturday, September 30, 2006
Genomic Evolution: Building the Body from Genes
Our organs tell stories. A pathologist, for example, can look at a lung and recognize a lifetime of toiling in a mine. Our genes tell stories, too. By comparing the genomic sequences of an ever-increasing number of organisms, we are now uncovering how our bodies came to be the way they are. Evolution, it seems, is a tale of détente: The need to adapt to changing environments is in a tug of war with the demand for precisely functioning biological machinery. The stories presented in the special section emphasize different facets of this complex saga. They are not just historical lessons; they have implications for understanding disease mechanisms as well as basic physiology.
When it comes to the story of the human brain, we are still stuck on the preface, Pennisi explains in a News story. Researchers are turning to comparative genomics to identify the main genetic characters that helped differentiate our brain from those of our primate cousins. They are finding evidence of positive selection for genes that are key to the size and complexity of the cortex, as well as provocative changes in gene copy number and expression.
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