It's interesting how wide the variation is on the number of species that have gone extinct. Here we have 869 species since 1500, while other respectable sources estimate 200 species a day.
More than 800 wildlife species now extinct
http://news.yahoo.com/s/nm/20090702/sc_nm/us_wildl...
More than 800 animal and plant species have gone extinct in the past five centuries with nearly 17,000 now threatened with extinction, the International Union for Conservation of Nature reported on Thursday.
A detailed analysis of these numbers indicates the international community will fail to meet its 2010 goal of bolstering biodiversity -- maintaining a variety of life forms -- a commitment made by most governments in 2002.
Based on data released in 2008 in the union's Red List, the new IUCN analysis is being released now to precede the 2010 target year and to draw a connection between crises in the financial and environmental realms, said report editor Jean-Christophe Vie.
The new analysis shows 869 species became extinct or extinct in the wild since the year 1500 while 290 more species are considered critically endangered and possibly extinct.
At least 16,928 species are threatened with extinction, including nearly one-third of amphibians, more than one in eight birds and nearly a quarter of mammals.
By comparison, the 2004 Red List showed 784 extinctions since 1500.
"We don't want to make a choice between nature and the economy; we just want to bring nature to the same level when you have to take a decision," Vie said by telephone from Switzerland.
The report said this is not a comprehensive list with only 2.7 percent of the 1.8 million described species analyzed.
The number of extinctions is "a gross underestimate but it does provide a useful snapshot of what is happening to all forms of life on Earth," the study authors wrote.
150-200 species lost a day?
http://www.bio.net/bionet/mm/bioforum/1996-April/0...
You're absolutely right about us not losing bird or mammal species at that rate. The species being lost are mostly insects, amphibians, and rare plants that have not even been cataloged yet. The estimated rate at which we are losing species is based on biological studies in the rainforests and the rate at which we are finding and cataloging newly discovered species (which is phenomenal - hundreds of new species are found each time a rainforest canopy tree is examined). The declining rate at which we find new species can be extrapolated into an estimate of the total number of species, which is used to estimate the rate of extinction by using a rate of habitat destruction (many of these species live in only one species of tree in one type of rainforest, while others are wide-ranging).
With increased population and corporation pressure to slash and burn rainforest for agricultural use, species we have never named are eradicated. NO, I can't tell you which species were lost yesterday, noone can. But, those species had probably been on this earth since before humans (humans are late-comers geologically and rainforests are ancient).
Speciation happens at a much slower rate than the present estimated rate of extinction. Over geological time, however, the earth rarely has periods of low species diversity. It rebounds from calamity quite quickly. The earth, however, has never been faced with a species like homo sapiens before, which is intelligent, adaptable, and persistent about changing the surrounding environment to suite itself.
Species would not be disappearing at nearly this rate if we were not around to "muck things up" unless a drastic global change were occurring.
Hope I helped to answer some questions.
Kristie L. Allen Environmental Statistics Group Biology Department Montana State University Bozeman, MT 59715 USA