The fact that human beings populate the whole earth does not mean they cannot go extinct in the next mass extinction event. So says a new theory of mass extinction events by a Leads-based scientist. According to the theory, widespread species are just as likely as rare ones to go extinct after global mass extinction events.
Under normal circumstances, species that are widespread are usually at a lesser risk than the species which are geographically confined to a specific region like in a case of regional environments catastrophe.
However, the study published in Nature Communications shows that this is not same in case of a global mass extinction event in which every species are equally vulnerable. There have been five such mass extinction events on earth. The last major wipe-out occurred some 66 million years ago when a giant asteroid hit the earth and put an end to the dinosaur species after their 150 long successful existence.
Researcher Dunhill Wills said that “The fact that the insurance against extinction given by a wide geographic distribution disappears at a known mass extinction event is an important result. 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. In contrast, the dinosaurs, which were comparatively rare and not as widespread pass through the extinction event and go on to dominate terrestrial ecosystems for the next 150 million years.”
Outside of these mass extinction events which put an end to anywhere from 50 to 95 percent of all life forms, species seem to disappear at a steady rate. Many scientists believe that we are entering a sixth mass extinction. According to Stanford scientist Paul Ehrlich, the mass extinction event is here “without any significant doubt.” That’s definitely bad news for humans.
Most of these mass extinction events happen due to a sudden climate change which is triggered by some cataclysmic event like a massive continental scale rupturing of volcanoes in the case of Triassic-Jurassic junction 200 million years ago.
“Organisms are unable to adapt quickly enough to rapidly changing conditions and thus become extinct” Dunhill said. The crocodile like animals became extinct and made way for the dinosaurs and they then made way for small mammals and birds after going extinct. Will the same thing happen to us, human beings? That’s a scary prospect.
The volcanic eruptions 200 million years ago put large amounts of CO2 and other greenhouse gases in the atmosphere causing rapid global arming.
“In effect, we are creating the same conditions today via human activity only on a more rapid time scale,” according to Dunhill, “Adding to that, human-caused habitat destruction and general exploitation of the natural environment is also a major driving force of extinction today.”
“You could say that we have altered our habitat so much that we may well be exempt from such evolutionary process. But most of the world’s population is still heavily dependent on the natural world for food water and energy. Massive and rapid upheavals in the natural environment will certainly impact humans in a negative way.” he added.
According to the researchers, it appears that such human driven mass extinction will affect all organisms, not just currently endangered and geographically restricted species.