Today conservation biologists, much like the early explorers of North America, strive to describe the variety of life living on Earth, from plants and animals to microbes.
While some estimates of species number have ranged as high as 100 million, the best current reckoning indicates that about 5 million species of eukaryotes—that is, everything above bacteria.
Current estimates suggest that species are going extinct at 0.01 to 1% per decade—that is 500 to 50,000 species lost each decade. Extinctions are driven by habitat destruction, introductions of exotic species from other continents, and increasingly climate change. The latter is predicted to drive up to 35% of species extinct during this century.
“What’s clear is that we are losing species at least a hundred or more likely a thousand times faster than the natural background rate of extinction.”
Stuart Pimm is the Doris Duke Professor of Conservation Biology at Duke University.
“Species have always gone extinct. Sometimes they’ve gone extinct in very big numbers as at the end of the cretaceous when the dinosaurs disappeared when the earth ran into a huge asteroid. But at the moment we are driving species to extinction a lot faster than they should be going naturally.”
Truly, we are entering an era of significant reduction in the diversity of the biosphere, largely as a result of the increasing number and impact of Homo sapiens worldwide.
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Web Extra
Full interview with Stuart Pimm, Doris Duke Professor of Conservation Biology at Duke University
[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2013/03/Pimm_interview_full.mp3|titles=Pimm_interview_full]Photo, taken on September 30, 2010, courtesy of Ryan Hagerty and USFWS via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY, with partial support from the Field Day Foundation.