Here’s a story, “Leaky Genes Put Evolution on the Fast Track, Pitt and UW-Madison Researchers Find” (Eurekalert, Jun 15, 2011) where
The team traced the development of a unique feature in a species of fruit fly that began with low-level gene activity and became a distinct feature in a mere four mutations as an existing gene took on a new function, according to a report in PNAS
Slight changes in DNA transcriptional enhancers can activate dormant genetic imperfections, causing “leakiness” or low level activity in developing tissue that is different from the genes’ typical location. A few more mutations can result in “a new function for an old gene.” One such gene found its way to becoming a permanent fixture in the ban of a species of fruit fly. However,
The Pitt-UW Madison work expands on research during the past 30 years demonstrating that new genes made from scratch are rare in animals, Rebeiz said. Instead, the diversity of living things is thought to stem from existing genes showing up in new locations.
The authors say that the usual location for the gene of interest was established 400,000 years ago (“a blip in evolutionary terms”) and four mutations later caused it to migrate.
“It has been long appreciated that nature doesn’t make anything from scratch, but the mystery has remained of how genes that have been performing the same job for hundreds of millions of years are suddenly expressed in new places,” Rebeiz said. “Our work shows that even slight mutations in a transcriptional enhancer can cause leaky gene activity, which can initiate a short route to the development of new traits.”
Just what the new trait is, is not revealed.
If the new trait were a business idea seeking a bank loan, some wonder how it would fare.
File under: Darwin’s Sure Thing