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"According to the World Conservation Union, a total of 784 species have become extinct since AD 1500, when accurate historical and scientific records began. While the vast majority of extinctions since that time have occurred on islands, over the past 20 years continental extinctions have become as common.
Scientists say that island-style extinctions are creeping onshore because continental habitats are being diced up by human activities-- a process that is creating what biologists term "virtual islands." Fences, asphalt, farms and cities -- not water -- are the boundaries which confine and isolate these man-made islands.
"Island biogeography is no longer an offshore enterprise. It has come to the mainlands. It's everywhere," says natural history writer David Quammen in his book "Song of the Dodo: Island Biogeography in an Age of Extinction."
"The problem of habitat fragmentation, and of the animal and plant populations left marooned within the various fragments that are untenable for the long term, has begun showing up all over the surface of the planet," he writes."
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http://www.planetark.com/dailynewsstory.cfm/newsid/28749/story.htm