Tristan Schnegelberger
Mr. Kozak
Part III
10 December 2012
"Mass Extinctions." Opposing Viewpoints Online Collection. Gale, Cengage Learning, 2010.
Gale Opposing Viewpoints In Context. Web. 7 Dec. 2012.
This article says there has been 5 mass extinction events in the history of the planet. The
earliest one took place over 450 million years ago destroying more than half of all life in the
world’s oceans. The most severe mass extinction event took place 250 million years ago and was
called the Permian Triassic event which destroyed 95% of all marine species and 70% of all land
vertebrate species. The most famous is the Cretaceous-Paleogene or also called the K-T event
and it occurred about 65 million years ago and resulted in almost all dinosaur species going
extinct.
MASS EXTINCTIONS. By: BENTON, MICHAEL J., New Scientist, 02624079, 3/5/2011, Vol.
209, Issue 2802
This article states that the End Permian extinction is the biggest of them all it took out 8090% of all land and marine species. It states that during this extinction something happened that
didn’t happen in any other which is that reefs and forest two giant structural ecosystems
disappeared. Reefs disappeared because major reef builders disappeared and it took 15 million
years for new coral to evolve and build reefs.
Stokstad, Erik. "Ancient weapon of mass destruction: methane gas?" Science 301.5637
(2003): 1168. Gale Opposing Viewpoints In Context. Web. 10 Dec. 2012.
This article argues that in the Permian-Triassic period methane gas may have caused the
mass extinction in which wiped out a vast majority of all species on land and in the ocean. It
talks about two papers and both of their views. One paper says that methane erupted from the sea
floor and incinerated land dwellers. The other theory states that the methane would have
suffocated its victims.
Esty, Amos. "Investigating a mega-mystery: two recent studies try to help unravel the causes of
late Pleistocene extinctions." American Scientist 93.5 (2005): 408+. Gale Opposing Viewpoints
In Context. Web. 10 Dec. 2012.
This article states that when humans crossed into to North America from Siberia around
12,000 there were giant short faced bears, enormous sloths, and dozens of other extinct species
that now we can only see in museums. It also says that the mystery extends far beyond North
America. Between about 50,000 and 10,000 years ago, near the end of the Pleistocene, much of
the world's megafauna disappeared. It says that humans could have been the cause for the mass
extinction or climate could have but they are both theories and don’t have much data to back it
up.
Grund, Brigid S.Surovell, Todd A.Lyons, S. Kathleen. "Range Sizes And Shifts Of North
American Pleistocene Mammals Are Not Consistent With A Climatic Explanation For
Extinction." World Archaeology 44.1 (2012): 43. MasterFILE Premier. Web. 11 Dec. 2012.
This article states that the cause of the terminal Pleistocene extinctions in North America is
debated but is most commonly blamed on climate change or overkill. Based on contemporary
extinction theory from conservation biology, we predict that in a climatically induced extinction
event, species with small geographic ranges are most likely to suffer extinction. We find that the
extinction event did not preferentially impact taxa with small geographic ranges, and that
displacement distances were no different for large- and small bodied species. These results are
not consistent with an extinction induced by climate change but may be concordant with
anthropogenic causes.
Marshall, Michael. "Mass-Extinction Fungi Could Turn On Trees Again." New Scientist
211.2826 (2011): 12. MasterFILE Premier. Web. 13 Dec. 2012.
This article states that like the largest mass extinction known to exist if climate weakens
trees to much then fungi could start to destroy a lot of trees and in the process lowering our
oxygen.
"Our Unpredictable Extinction." New Scientist 207.2777 (2010): 20. MasterFILE Premier. Web.
13 Dec. 2012.
This article says there is a mass extinction on the way but there is no way to tell what
species will survive.