How Current Animal Extinctions Will Affect Future
“No one can predict which species will be around.”
New research by paleobiologist Dr. John Alroy predicts serious consequences for life on Earth in wake of the current mass extinction of animal species.
Dr. Alroy’s findings indicate that as a result of a range of factors, the major extinction event currently underway will be much more severe than has been seen in most other major periods of mass extinction. Alroy notes there have been only three mass extinctions on the level of the current one in the last half billion years. The most recent was the dinosaur extinction 65 million years ago.
Dr. Alroy said today’s extinction is due to a range of human behaviors and activities coupled with the effects of climate change. His findings were published this week in the international journal Science.
Dr. Alroy, an Australian who is Professor of Paleobiology at Macquarie University, used the massive Paleobiology Database, which compiles data from nearly 100,000 fossil collections worldwide. He tracked the fate of major groups of marine animals throughout the fossil record and during the Earth’s most massive extinction event, which occurred 250 million years ago.
He concludes that the actual rules governing diversity have actually changed through time. That means a group’s average rate of diversification or branching into new species in the past is not a good predictor of how well it will fare after a mass extinction.
In other words, organisms that might have adapted in the past may not be able to this time.
“You may end up with a dramatically altered sea floor because of changes in the dominance of major groups,” he explained. “That is, the extinction occurring now will overturn the balance of the marine groups.”
When there is a major mass extinction, it’s not just a temporary drop in richness of species.
Dr. Alroy likens what is happening now to rolling the dice with evolution.
“What’s worrisome is that some groups permanently become dominant that otherwise wouldn’t have. So by causing this extinction, we are taking a big gamble on what kind of species will be around in the future. We don’t know how it will turn out. People don’t realize that there will be very unpredictable consequences.”