Math Glitch Means Extinction Risks for Endangered Species Underestimated

A new study has indicated that extinction risks for natural populations of endangered species are likely being underestimated by as much as 100-fold because of a mathematical misdiagnosis .

A mathematical "misdiagnosis" may be responsible for underestimating the risk of extinction for endangered species, a new study has found.

According to Assistant Professor Brett Melbourne of CU-Boulder's ecology and evolutionary biology department, who led the research, current mathematical models used to determine extinction threat, or "red-listed" status, of species worldwide overlook random differences between individuals in a given population.

Global Warming�s Major Victim Could Be Insects in Tropics
Global warming’s major victim could be insects in tropics, experts warn.

Such differences, which include variations in male-to-female sex ratios as well as size or behavioral variations between individuals that can influence their survival rates and reproductive success, have an unexpectedly large effect on extinction risk calculations, according to the study.

"When we apply our new mathematical model to species extinction rates, it shows that things are worse than we thought," said Melbourne.

"By accounting for random differences between individuals, extinction rates for endangered species can be orders of magnitude higher than conservation biologists have believed," he added.

One-sixth of Europe's Mammals Face Extinction, Warns Conservation Experts
A comprehensive survey carried out by the World Conservation Union (IUCN) has said that a sixth of Europe's mammal species is threatened with extinction.

Currently, extinction risk models are based primarily on two factors, according to Melbourne.

One is the number of random events adversely affecting individuals within a population.

Mass Extinction of Amphibians Within Three Decades Through Deadly Fungus
Within three decades biologists have warned that the entire population of the world's frogs and other amphibians could be wiped out like the dinosaurs by a deadly fungus .

"While a sequence of such random events in a small population can have a big impact, such events are far less likely to affect larger populations," said Melbourne.

The second risk factor used widely in extinction risk models is the impact of external, random events like temperature and rainfall fluctuations that can influence birth and death rates of individuals in a population.

Scientists Concerned Over Extinction of Large Number of Medicinal Plants
Large number of medicinal plants are at risk of extinction, and could spark a global health crisis, according to experts.

But two additional factors highlighted by the researchers in a new study - sex ratio variations and physical variation between individuals within a population - have been ignored or mischaracterized by most extinction risk modelers.

"There has been a tendency to misdiagnose randomness between individuals in a population by lumping it with random factors in the environment, and this underestimates the extinction threat," said Melbourne.

For the study, the researchers monitored populations of beetles in lab cages and the results were used to test the new mathematical models.

"The results showed the old models misdiagnosed the importance of different types of randomness, much like miscalculating the odds in an unfamiliar game of cards because you didn't know the rules," said Melbourne.

According to the study's authors, "We suggest that extinction risk for many populations of conservation concern need to be urgently re-evaluated with full consideration of all factors contributing to stochasticity, or randomness."

Source-ANI
RAS/M