A new study published in the journal Nature Communications finds that even geographically widespread species with large populations, like human beings, may not be spared during a global mass extinction.
Living species have experienced five mass extinction events during Earths history. All were due to some kind of rapid environmental change, including climate change, caused by massive volcanic eruptions and asteroid impacts.
The last mass extinction happened some 65 million years ago when the dinosaurs and more than 75 percent of all other species perished due to the Chicxulub asteroid impact off what is now the Yucatán peninsula.
In the 21st century, with dozens of species disappearing every day at a rate thousands of times faster than normal, many scientists believe Earth is entering its sixth major extinction event. The reason: the rapid warming of global temperatures due to human activities, particularly the burning of fossil fuels.
Now, a new study published in the journal Nature Communications, finds that even geographically widespread species with large populations, like human beings, may not be spared during a global mass extinction.
Researchers from the School of Earth and Environment at the University of Leeds and the University of Baths Milner Centre for Evolution in the UK studied the fossil record of land-dwelling vertebrates living 252 to 145 million years ago during the Triassic and Jurassic periods, a statement by the University of Leeds said.
While a species distribution over wide geographical areas does offer a kind of insurance against extinction, that insurance becomes null and void during a mass extinction event, the researchers found.
The fact that the insurance against extinction given by a wide geographical distribution disappears at a known mass extinction even is an important result, says Dr. Alex Dunhill of the University of Leeds in the statement. Many groups of crocodile-like animals became extinct after the mass extinction event at the end of the Triassic era, despite being really diverse and widespread beforehand.
What does this mean for humans? No one really knows for sure, but the prospects do not look good.
These results shed light on the likely outcome of the current biodiversity crisis caused by human activity, Dr. Dunhill adds. It appears a human-driven sixth mass extinction will affect all organisms, not just currently endangered and geographically restricted species.