Wednesday, October 29, 2014

Mass Extinctions


                                                                         
                                                                         


Mass extinctions of many species have happened before.   Five times, actually.   At the end of Permian era, 299 to 251 million years ago before the continents were formed, mass extinction led to  95% of all species being wiped out. In this situation it was naturally caused by extreme climate fluctuations.  You can get a little more detail here. The process of extinction took millions of years;  nothing happened overnight.

Species naturally come and go.  Some scientists have postulated that we are in a period of accelerated extinctions.  In the past mammals became extinct at a rate of less than two species per million years.   But in the past 500 years, 80 mammals out of 5570 species of mammals have gone extinct.  And that's a conservative estimate.   The fact that it can be attributed to humans and that it has happened so quickly is especially disconcerting.    Professor Anthony Barnosky, writing in the Huffington Post, tries to present a hopeful outlook.  Perhaps because, if we decide it's hopeless, no efforts will be made.  But it is critical.

Climate change, destruction of tropical rain forests, the market for trinkets made out of ivory and aphrodisiacs made out of rhinoceros horn are matters we may feel we have little or no control over and that other people are responsible.

One of Professor Barnosky's suggestions is to simply get out and enjoy nature; you'll come to value it.     For further reading, his book, Dodging Extinction is out this month.   As a review states, "Read this book and you will demand change."

                                                                  

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