May 10, 2007 (Science Daily) – A tiny opossum’s genome has shed light on how evolution creates new creatures from old, showing that change primarily comes by finding new ways of turning existing genes on and off.

The research, by an international consortium led by the Broad Institute of MIT and Harvard, revises our understanding of genetic evolution. Scientists previously thought that evolution slowly changed the genes that create specific proteins. As the proteins changed, so did the creatures that owned them.

The current research shows that opossum and human protein-coding genes have changed little since their ancestors parted ways, 180 million years ago. It has been the regulation of their genes – when they turn on and off – that has changed dramatically.

“Evolution is tinkering much more with the controls than it is with the genes themselves,” said Broad Institute director Eric Lander. “Almost all of the new innovation … is in the regulatory controls. In fact, marsupial mammals and placental mammals have largely the same set of protein-coding genes. But by contrast, 20 percent of the regulatory instructions in the human genome were invented after we parted ways with the marsupial.”…


Interestingly, the next part in the series I’ve been writing here deals with issues similar to this. But I should point out a couple of things here, since that post will not deal with this completely: