UMDNJ Researchers Discover Novel Mechanism of Complex Evolutionary Change
STRATFORD, NJ—Scientists at the UMDNJ-School of Osteopathic Medicine have discovered how two different species solved the same evolutionary problem; how to create self-fertile animals that do not need to mate with males in order to produce offspring. Their discovery explains not only how this particular change occurred millions of years ago, but also suggests explanations for other complex changes that have occurred throughout evolutionary history. The researchers’ findings appear in the November 17 edition of Current Biology.
The research involves two similar species of nematodes, C. elegans and C. briggsae. Both species possess roughly 20,000 genes. Humans have about 30,000 genes.
The worms are self-fertile hermaphrodites, but each species descended from “normal” male/female ancestors. The UMDNJ researchers discovered that new genes evolved independently in the two species. Each came to manipulate the same critical protein that, in turn, causes self-fertility. Surprisingly, both new genes share a common structure (called an F-box), but they are not otherwise related, and they work in very different ways to create hermaphrodites.
“It’s as if you had two cars, and discovered that one ran better when you put a book in the engine compartment and that the other ran better if you put a similar book in the muffler,” said Ronald Ellis, Ph.D., the study’s corresponding author and an associate professor of Molecular Biology at the UMDNJ-School of Osteopathic Medicine. “We were surprised that the same type of gene evolved to create hermaphrodites, when so many other solutions seemed possible. But we were even more surprised that despite their similarities, these two genes work in very different ways.”
Ellis added, “Our research shows how new genes arise to create new traits. We know that humans arose through a long process of evolution, and the better we understand the evolutionary process, the better we’ll be able to understand how the human genome works by extrapolating from studies such as this.”