MASS EXTINCTION. Biologists: "Rates of extinction appear now to be 100 to 1,000 times greater than background levels, qualifying the present as an era of “mass extinction”"

Dr Donald A. Levin is Professor of Biology, University of Texas, Austin; his son Dr Phillip Levin is a biologist with the US National Marine Fisheries Service (see: http://www.soc.duke.edu/~pmorgan/levin&levin.2002.the_real_biodiversity_crisis.html ).

Dr Phillip S. Levin and Dr Donald A. Levin Rates of current rates of extinction that appear now to be 100 to 1,000 times greater than background levels (2002) ( “The numbers are grim: Some 2,000 species of Pacific Island birds (about 15 percent of the world total) have gone extinct since human colonization. Roughly 20 of the 297 known mussel and clam species and 40 of about 950 fishes have perished in North America in the past century. On average, one extinction happens somewhere on earth every 20 minutes. Ecologists estimate that half of all living bird and mammal species will be gone within 200 or 300 years. Although crude and occasionally controversial, such statistics illustrate the extent of the current upheaval, which spans the globe and affects a broad array of plants and animals…The current losses are, however, exceptional. Rates of extinction appear now to be 100 to 1,000 times greater than background levels, qualifying the present as an era of “mass extinction”. The globe has experienced similar waves of destruction just five times in the past.” [1].

[1]. Phillip S. Levin and Donald A. Levin, “The Real Biodiversity Crisis”, Macroscope,January-February 2002 : http://www.soc.duke.edu/~pmorgan/levin&levin.2002.the_real_biodiversity_crisis.html ).