New study tests Red Queen Hypothesis
In Lewis Carroll's "Through the Looking Glass," the Red Queen described her country as a place where "it takes all the running you can do, to keep in the same place." From this, the Red Queen hypothesis has been formed.
Also referred to as the Red Queen Effect, this evolutionary hypothesis proposes that organisms must constantly adapt, and evolve not only to reproduce, but also to survive against all opposing organisms that are evolving in an ever-changing environment.
In biology, this means that animals and plants don't just disappear because of bad luck in a static and unchanging environment. Instead, they face constant change — a deteriorating environment and more successful competitors and predators — that requires them to continually adapt and evolve new species just to survive.
A University of California, Berkeley, study was designed to test this popular theory and found that a lack of new, emerging species can contribute to extinction.
Charles Marshall, director of the UC Berkeley Museum of Paleontology and professor of integrative biology, and co-author of the report stated: "...We found that a decrease in the origin of new species is just as important as increased extinction rate in driving mammals to extinction." While this process would play out over millions of years, the findings should help biologists understand the pressures on today's flora and fauna and what drove evolution and extinction in the past.
The study analyzed 19 groups of mammals that are either extinct or are in decline. Though the specific cause of declining originations and rising extinctions for these groups is unclear, the researchers concluded that the mammals' death was not just dumb luck.
"Each group has either lost, or is losing, to an increasingly difficult environment," Marshall said. "These groups' demise was at least in part due to loss to the Red Queen - that is, a failure to keep pace with a deteriorating environment."
Marshall and former UC Berkeley post-doctoral fellow Tiago Quental found that the animal groups were initially driven to higher diversity until they reached the carrying capacity of their environment, or the maximum number of species their environment could hold. After that, their environment deteriorated to the point where there was too much diversity to be sustained, leading to their extinction.
"In fact, our data suggest that biological systems may never be in equilibrium at all, with groups expanding and contracting under persistent and rather, geologically speaking, rapid change," he said.
The study was published this week in the journal Science Express.
Read more at the University of California Newsroom.
Evolution image via Shutterstock.