The History of Earth's Mass Extinctions

The History of Earth's Mass Extinctions

The four billion year history of earth has witnessed five mass extinctions, and some scientists believe that we are on the verge of the sixth.1[1] If we are in the midst of the next mass extinction, we are in the very early stages of an evolving, and escalating process. The most recent, or fifth mass of the extinctions occurred 65 million years ago at the boundary between the Cretaceous and Tertiary periods. Images of an asteroid colliding with the planet, decimating the dinosaur population have been in circulation since the early 80’s.2[2] Being the most recent mass extinction, thousands of scientists around the world have investigated it, and elementary school children are familiar with it.

While the asteroid-collision hypothesis has not been proven concretely, it has been widely assimilated into, and accepted by the popular culture. Palaeontologists, sedimentologists, palaeoceanographists, geochemistrists, and experts in numerous other related fields have recently stepped up investigative efforts concerning the mass extinctions.3[3] Knowledge about these previous mass extinctions would not only give us a better understanding our past, but it could be vital in the study and recognition of a sixth mass extinction.

Geologists studying basalt flats in Siberia are discovering evidence that a massive lava eruption in that region 250 million years ago may have been more devastating than previously believed. In their latest figures, the investigating scientists believe that 85% of all aquatic species, and 70% of all species living on land became extinct at this juncture in time. Figures three times that of the Cretaceous-Tertiary extinction.4[4] The belief is that the lava ...

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[10] Virginia Morell. “The Sixth Extinction,” National Geographic.

[11] http://www.amnh.org/museum/press/feature/biofact.html. American Museum of Natural History.org

[12] http://www.amnh.org/museum/press/feature/biofact.html. American Museum of Natural History.org

[13] http://www.newscientist.com/news/print.jsp?id=ns99994797. NewScientist.com

[14] http://www.newscientist.com/news/print.jsp?id=ns99994797. NewScientist.com

[15] http://www.amnh.org/museum/press/feature/biofact.html. American Museum of Natural History.org

[16] Ayres, Ed. “Worldwatch Report: Fastest Mass Extinction in Earth History,” 16 September 1998.

[17] http://www.geol.umd.edu/~tholtz/G331/331extin.htm.

[18] http://www.mdgekko.com/devonian/opportunity/massExtinction.html. Devonian Times.

[19] http://www.ucmp.berkeley.edu/paleozoic/paleozoic.html.