What is Permian Extinction: Permian extinction, which occurred about 251 million years ago, is the greatest mass extinction that ever happened in the history of earth.
Immediate Consequence: Marine lives received the most damage from the mass extinction. The Permian extinction killed off at least 50 to 60 percent of all marine general, eliminating about 90 percent of marine species.
What caused it: It is accepted that a continental-scale volcanic eruption of lava in present-day Siberia caused the Permian extinction. Some examples of consequences were depletion of oxygen, acidification of ocean waters, global warming, and climate fluctuations. According to Sid Perkin's article in "Science News" Jan 14, 2010, Usually, the most limiting nutrient for phytoplankton is iron. However, acidification of ocean drops phytoplankton’s iron uptake, therefore dropping photosynthesis rate. This phenomenon further exacerbated oxygen depletion in the ocean during Permian extinction.
Post Permian: Animals became greatly more diversified as time passed.
- For example, according to an article (The New York Times, Sept 1 2009)by Henry Fountatin, while only three genera of one ammonoid suborder survived the extinction, after million years, more than 100 genera thrived.
- According to the article "The Search for Evidence of Mass Extinction"(Natural History, Sept 2009), in contrast to simple, filter-feeding, and sedentary benthic animals that dominated the Permian, after the mass extinction, more diverse group of mobile animals began to appear in abundance. Some of the new animals were highly sophisticated and bore better skeletal defenses.
post permian marine life
- According to the same source as above, there was a trend toward greater evenness in abundance. The ecological niche also became more diversified compared to the Paleozoic period when the majority of organisms competed for the same resources, which were matters floating in the water column.
- Post-Permian period, 251 millions years after the extinction, full-scale invasion of marine reptiles began. There were two reasons for this: one, the extinction wiped out nearly every marine creature, which meant that the sea was empty for colonisation. Two, the huge volcanic eruption brought up the global temperature, and the reptiles were able to thrive in ice-free environment. (James O-Donoghue, New Scientist, Oct 27 2009)
Concluding Comments: Despite intervals of decline due to mass extinctions, the most catastrophic being the permian extinction, marine genera increased overall since the Cambrian period. This trend highlights the resilience of nature, showing that survivors, no matter how decimated, will eventually evole new complex communities and will endure modern environmental degradation due to global warming.
Related Video Link: http://www.youtube.com/watch?v=hDbz2dpebhQ
Primary Source:
Scott, Peter J., Matthew A. Kosnik, “The Search for Evidence of Mass Extinction.” Natural History (September 2009): 26-32. Feb 8, 2010.
Supplementary Sources:
1. James O-Donoghue. “Real Sea monsters: The hunt for predator X.” New Scientist. Oct 27, 2009. Feb 11, 2010.
2. Sid Perkins. “Acidifying Ocean May Stifle Phytoplankton.” Science News. Jan 14, 2010. Feb 11, 2010.
3. Henry Fountain. “Some Mollusks Thrived After a Mass Extinction.” The New York Times. Sept 1, 2009. Lexis-Nexis. Cox Milton Library. Feb 11, 2010.
Image Sources:
http://web.uvic.ca/~stucraw/Lethbridge/MyArticles/GlobalEconomy_files/IMAGE006.JPG
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWG7U2IjWBz6MpRIKeu89legAJ2u3wPBN90N64jZ2Ls4jzsUj6_ViiwyA2E6HPueART36XRxSwqKrKjz8Na57pi10zpsRjLzCqu_8hpD8SAinyACKO0cij_zzQ4RA4sM94ZZtfO0Yx2IQ/s320/permian_marine.jpg
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