"The answer is, except for that 2%, people didn't evolve new genes. They made different use of the ones they had. The key point is what kind of enzymes and proteins a gene turns on and off at particular times in the development of the organism. Research at the turn of the century suggested that complex adaptions, such as a bird's beak changing shape to better crack open seeds, as Darwin might have observed on the Galapagos Islands, happen simply with this mechanism."

"Sticking with our human and chimpanzee case, researchers at Duke University focused on a gene that makes a protein involved in memory and perception. Although the protein is exactly the same in human and chimpanzee brains, the Duke team found that humans have evolved minute genetic changes that cause brain cells to make, more of the crucial protein, perhaps helping the human brain to work better. A little less of these proteins here, a little more of those proteins there, and Mr. Johnson dozing in the last row becomes a chimp."

There were a lot more laughs at that. Johnson had the rep of being a party animal. The laughs woke him up.

"The chimpanzee research," she continued, "was part of a profound conceptual shift. Biologists found that 'gene expression' - the way cells make more of some proteins and less of others and when they do it - plays an important role in explaining the way one species evolves into another with sometimes astounding speed. Moreover, these changes are really ubiquitous - there's that word you all love again. I would dare say that life would not have been possible on our planet without them."