Species that are older run less risk of extinction than species that have existed a shorter time. That is apparent from a study recently published by an international research team that included scientists from the University of Gothenburg.
The study shows that the extinction risk for predators such as wolves, bears and tigers is highest shortly after the species has formed. The results are based on studies of thousands of fossils in which researchers found that the risk of extinction of the species decreased with the species’ age. The species studied are all predators.
For a species that had survived for a million years, for example, the probability of it dying out was 50 per cent less than for a species that had just been formed. The average lifespan of species living as predators is around two million years. But during the last 40 million years, most species have died out much earlier, although there are species that have survived for more than 10 million years. “Knowing how the species’ age affects the risk of extinction can give us important insights into early evolutionary history and help us predict the future of species,” says Daniele Silvestro, researcher at the Department of Biological and Environmental Sciences. “But it’s not clear to what extent the historical patterns of extinction can be transferred to today’s extinction risk, because the species existing today are strongly affected by human activities.”