Scientists may have cracked the ‘aging process’ in species

New research from the University of Kansas may solve a mystery in the “aging process” in species — or, how a species’ risk of extinction changes after it appears on the scene.

for the year, Evolutionary biologist He believes that older species have no real advantage over younger ones in surviving extinction—an idea known among researchers as the “Red Queen Theory.”

“The Red Queen theory is that species have to keep running just to keep quiet, like the characters in Lewis Carroll’s book ‘Through the Looking Glass,'” said lead author James Salisbury, a postdoctoral researcher in the Department of Ecology and Evolutionary Biology. said KU. “This idea evolved into a kind of ecological theory in the 1970s in an attempt to explain an observation. Threat of extinction The age of the species has not changed.”

Yet the years have not been kind to this theory.

“In early investigations of this phenomenon, species of all ages appear to be going extinct at roughly the same rate, perhaps only because of the relative inconsistency of the evidence available at the time,” Saulsbury said. “This is realized under the Red Queen model, where species are constantly competing with other species that are adapting to them.”

But as more data was collected and analyzed in more sophisticated ways, scientists increasingly disproved the Red Queen theory.

“Scientists continue to find instances where young species are particularly vulnerable to extinction,” Saulsbury said. “So we had a theory vacuum—a bunch of unusual observations and no agreed-upon way to make sense of them.”

But now, Saulsbury has taken the lead The research is revealing I Proceedings of the National Academy of Sciences Who can solve this mystery? Saulsbury and his co-authors show that the relationship between a species’ age and its extinction risk can be accurately predicted by an ecological model called “Neutral view of biodiversity.”

The neutral hypothesis is a simple model of ecologically similar species having to compete. Limited resourceswhere the outcome of each species is more or less random.

According to the theory, “species either become extinct or expand from a small initial population size to become less vulnerable to extinction, but they are always susceptible to being replaced by their competitors”. Add a summary of the PNAS By extending this theory to make predictions for the paper The fossil recordSaulsbury and colleagues found that the unbiased theory “predicts survival among fossil zooplankton with surprising accuracy and generally accounts for empirical deviations from Red Queen’s predictions.”

Saulsbury’s co-authors were C. Tomomi Parins-Fukuchi of the University of Toronto, Conor Wilson of the University of Oxford and the University of Arizona, and Trond Retten and Li Hsiang Liu of the University of Oslo.

While neutral theory may seem like a curtain call for the Red Queen theory, the UK researcher said the Red Queen still has value. Basically, it still holds true that species compete against each other for limited resources in a zero-sum game, always fighting for a bigger piece of nature’s pie.

“The red queen theory has been a compelling and important idea in the evolutionary biology community, but data from the fossil record no longer supports the theory,” Saulsbury said. “But I don’t think our paper really refutes that idea because, in fact, the red queen theory and the neutral theory are, in a profound way, quite similar. Biological interactions result in species for resources and sustainable turnover in communities. “

Ultimately, the findings not only help make sense of the forces that shape the natural world but can be relevant to it. Conservation efforts As species face increasing threats from climate change and habitat loss worldwide.

“What makes a species extinct?” Salisbury asked. “People are interested in learning from the fossil record to see if it can tell us something to help conserve species. The frustrating aspect of our study is that there are environmental conditions where the fate of species is completely unknown. are not predicted. There is some limit to how many extinctions we can predict. To some extent, extinctions will be decided by seemingly random forces—accidents of history. Some paleontological studies for this The support is there.”

Attempts have been made to understand the predictors of extinction in the fossil record, but so far many generalizations have not emerged, he said.

“There is no trait that makes you immortal or invulnerable to extinction,” Saulsbury said. “But the promising aspect of our study is that there may be patterns of extinction of whole communities that are quite predictable and understandable. We can get a good grasp of the characteristics of the biota, such as age. as well as how the extinction risk of species changes. If the fate of a single species is difficult to predict, the fate of an entire community can be quite understandable.”

Saulsbury adds a caveat: It remains to be seen how well neutral explanations of extinction hold up across different parts of the tree of life.

“Our study is also working on a geological time scale of millions of years,” he said. “Things look very different in our own lifetimes.”