Scott Berkun

11 Responses

• 
• bbz - February 15, 2007 at 11:29 pm #

• I found lots of info about how many species exist now, but only one about how many ever existed. So the estimate is 200 million to 1 billion and up. Thanks for the challenge.

  “Extinction is part of the natural process of evolution. The one and a half million species, which are now conservatively estimated to exist, represent less than one percent of the total number of species ever present on this planet (Nei, 1975).” (1)

  2 – 100 million species exist today. (2)
  4 – 6 million ” (4)

  “Between about 1.5 and 1.75 million species have been discovered and scientifically described thus far (LeCointre and Guyader, 2001; Cracraft, 2002).” (and more gold from there) (3)

  (1) http://www.fao.org/DOCREP/004/T0559E/T0559E02.htm
  (2) http://hypertextbook.com/facts/2003/FelixNisimov.shtml
  (3) http://cnx.org/content/m12174/latest/
  (4) http://www.scienceagogo.com/news/20020328223914data_trunc_sys.shtml

  
  

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• Scott (admin) - February 16, 2007 at 12:16 am #

• Behold the power of blogs! Thanks John, nicely done.

  Anyone think they can top that?

  
  

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• Robin - February 16, 2007 at 2:29 am #

• I just read about the “All Species Foundation” at Kevin Kelly’s website a few days ago. “The organization would catalog very living species on earth within one human generation (25 years).”
  http://www.kk.org/narrative/index.php

  Maybe the following information could help you:
  “Estimates of undiscovered species on Earth range from 10 million to 100 million and The US National Science Board ( 1989) predicted that as many as 25% or more of the Earth’s species may become extinct by 2014″
  http://www.all-species.org/faq_response.html#identified

  kind regards,
  Robin

  
  

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• J. Heijmans - February 16, 2007 at 5:44 am #

• This 1991 New Scientist article mentions that “estimates of the total progeny of evolution range from 5 to 50 billion species”.

  http://www.newscientist.com/channel/life/endangered-species/mg13117862.300

  
  

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• Sam Greenfield - February 16, 2007 at 7:49 am #

• I recommend citing sources rather than trying to “site” or even “sight” them. :-)

  
  

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• Scott (admin) - February 16, 2007 at 9:25 am #

• Sam – what are you trying to get mentioned in the book as a wise-ass or something? :)

  
  

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• Mikko Heikkinen - February 16, 2007 at 2:55 pm #

• Few estimates/guesses on the amount of species that have existed:

  G. G. Simpson 1952: How Many Species? Evolution, Vol. 6, No. 3, p. 342
  http://links.jstor.org/sici?sici=0014-3820(195209)6%3A3%3C342%3AHMS%3E2.0.CO%3B2-E
  50-4000 million species

  A. Cailleux 1954: How many species? Evolution vol, 8 p. 82-83
  http://links.jstor.org/sici?sici=0014-3820%28195403%298%3A1%3C83%3AHMS%3E2.0.CO%3B2-Z
  17-860 million species

  Estimates on the amount of species living vary between 5 to 50 million, according to J. E. Winston 1999: Describing Species (and its references). About 1.4 million of those are known to science.

  Few other references that might help but which I don’t have access to:

  A. S. Iberall 1989: How many species? GeoJournal Volume 18, Number 2 / March, 1989
  http://www.springerlink.com/content/r730hjh065376375/

  D.M. Raup 1986: Biological extinction in Earth history. Science 231,1528-1533
  http://www.sciencemag.org/cgi/content/abstract/231/4745/1528

  
  

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• Scott (admin) - February 19, 2007 at 9:37 am #

• From Greg:

  The IUCN has listed 735 animals (698 species and 37 subspecies) as recently extinct (extinctions since 1500 AD) at their website: 2006 IUCN Red List of Threatened Species. The 2003 Red List only listed 717 animals and the 2004 Red List listed 734 animals.

  Found this quote here:
  http://www.petermaas.nl/extinct/animals.htm

  References this as a source:
  http://www.iucnredlist.org/

  
  

• 
• Peter Montgomery - February 19, 2007 at 12:04 pm #

• One more note
  Headline: MOST of the species that have ever existed do NOT exist today.

  Details: Due to the half dozen major cataclysmic events in the Earth’s history, there have been several times (such as 65 million years ago), when MOST of the Earth’s species have been eliminated. These major events go back to life’s early roots. 2+ billion years. This is in addition to the normal processes for evolution / mutation which cause species die-off.

  (without citation I’m afraid). -Peter

  
  

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• Susan - February 19, 2007 at 5:13 pm #

• Don’t forget the bugs!

  http://news.nationalgeographic.com/news/2005/09/0920_050920_extinct_insects.html

  “Insects make up 80 percent of all known animal species. Though only 900,000 insects have been identified, experts agree that there are still vast numbers of undocumented species. Estimates vary, but some researchers believe that as many as 2 to 100 million insect species could exist.”

  And the plants!

  http://www.nationalgeographic.com/ngm/0009/feature4/fulltext.html

  “About 250 million years ago, at the end of the Permian period, something killed some 90 percent of the planet’s species. Less than 5 percent of the animal species in the seas survived. On land less than a third of the large animal species made it. Nearly all the trees died.”

  
  

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• Bruce Hughes - March 15, 2007 at 8:45 am #

• I would recommend you start in the Back Matter of Edward O. Wilson’s “the Diversity of Life”, which you can search on Amazon.