Biologits at the University of California, Berkeley have found that a lack of new emerging species contributes to extinction over a period of millions of years. The research team studied 19 groups of mammals that either are extinct or in decline from a past peak in diversity, as in the case of horses, elephants, rhinos and others.
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.
“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.”
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 findings should help biologists understand the pressures on today’s flora and fauna and what drove evolution and extinction in the past.”
Reference: Tiago B. Quental, Charles R. Marshall, How the Red Queen Drives Terrestrial Mammals to Extinction, Science Express, 2013, DOI: 10.1126/science.1239431
The Daily Galaxy via University of California, Berkeley and Science Express