GAINESVILLE, Fla. Survival of the fittest has popularly described evolution for more than a century, but a new study published in the Royal Society journal Biology Letters provides further evidence that random genetic mutations over millions of years may also play a powerful role.
Writing online this week, Florida and California scientists are the first to link the evolution of proteins the organic compounds that determine the structure and function of living things to a species metabolic rate.
Across species from fish to mammals, they found that rates of protein evolution showed the same body size and temperature dependence as metabolic rate. Specifically, their mathematical model predicts that a 10-degree increase in temperature across species leads to about a 300 percent increase in the evolutionary rate of proteins, while a tenfold decrease in body size leads to about a 200 percent increase in evolutionary rates.
It does suggest that if there were an evolutionary arms race between a small, hot animal and a cold, big animal, its going to be awfully hard for the cold, big animal to keep up, said James F. Gillooly, an assistant professor of zoology in the University of Florida College of Liberal Arts and Sciences and a member of the UF Genetics Institute. But really, what we are showing is that neutral processes, processes that do not depend on natural selection, are important in governing its evolution.
Natural selection, a concept first introduced by British naturalist Charles Darwin in 1859, is a cornerstone of biology that says evolution is driven by organisms passing along beneficial traits that help them survive and reproduce while weeding out unfavorable ones.
We know evolution depends on the environment in which an animal lives, Gillooly said. And yet this study suggests that you can look at different species and without knowing anything at all about their pressures to survive and reproduce in their re
|Contact: John Pastor|
University of Florida