Was the Red Queen from the famous story ‘Through the Looking Glass’ right? Do you need to run in order to stay in the same place? On the larger scales of time this may be true with regards to evolution, according to new research from UC Berkeley — without continually emerging and spreading species, groups and genera often find themselves on the path to extinction.
Image Credit: Illustration by Sir John Tenniel from Lewis Carroll’s Through the Looking-Glass, 1871
“Virtually no biologist thinks about the failure to originate as being a major factor in the long term causes of extinction,” said Charles Marshall, director of the UC Berkeley Museum of Paleontology and professor of integrative biology, and co-author of the report. “But we found that a decrease in the origin of new species is just as important as increased extinction rate in driving mammals to extinction.”
What this means is that rather than animals and plants disappearing because of ‘bad luck’ in a static and unchanging environment, “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.”
While this may sound like common sense, it’s a conception that apparently doesn’t have much representation/backing in the scientific community.
Such decreases would play out rather slowly — over millions of years, the researchers note. So the knowledge doesn’t particularly apply to our current situation — the relentless extinctions of animal and plant life currently occurring as a result of human activities, the 6th Great Mass Extinction Event. But the research certainly does have some relevance — and should help to further our understanding of the pressures on today’s flora and fauna.
UC Berkeley provides details on the research:
The results come from a study of 19 groups of mammals that either are extinct or, in the case of horses, elephants, rhinos and others, are in decline from a past peak in diversity. All are richly represented in the fossil record and had their origins sometime in the last 66 million years, during the Cenozoic Era.
The study was designed to test a popular evolutionary theory called the Red Queen hypothesis, named after Lewis Carroll’s character who, in the book ‘Through the Looking Glass,’ described her country as a place where “it takes all the running you can do, to keep in the same place.”
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 stated. “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 researchers 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.” (Author’s note: “Too much diversity too be sustained” is poor wording on the part of the researchers — it’d be much more accurate to just state that complex systems are more fragile than simple ones, and that there is only so much life that a given environment can sustain. Expansion and growth brings those limits to the forefront.)
“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,” Marshall continued.
Truthfully though — this is all entirely speculation… It’s an extremely complex subject, one composed of extremely large numbers of extremely complex interactions… Mental conceptions and scientific models will never provide a clear, truly reliable ‘answer’ in this regard… Just theories.
The new research was just published in the journal Science Express.
