Humans May Have Limiting Effect on the Origin of (New) Species

Posted on by Lori Jia

The New York Times, May 23, 2006

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Humans can threaten species with extinction in many ways, including overfishing, pollution and deforestation. Now a pair of studies points to a new danger to the world’s biodiversity: humans may be blocking new species from evolving.

New species evolve when old species split apart. Animals living on a peninsula might become cut off from the mainland by rising sea levels, for example.

They would adapt to life on the island and acquire mutations not shared by the rest of their species. If the sea level should drop and the animals could mix together again, the mutations might make it less likely that the two populations could interbreed. They would be on their way to becoming separate species.

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Manimals, Sticklebacks, and Finches

Posted on by Lori Jia

In tomorrow’s New York Times I have an article about the origin of species–or rather, blocking the origin of species. The evolution of a new species can be a drawn out process, taking thousands or millions of years. First populations begin to diverge from each other. Later, those populations may become divided by significant reproductive barriers. Even after those populations have evolved into separate species, they may still be able to produce hybrids in the right conditions. In some cases, those hybrids may remain rare and the two species will remain intact. In other cases, the species may collapse back on each other.

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Jakob the Hobbit?

Posted on by Lori Jia

It’s been a little over a year and a half now since scientists announced the discovery of the most controversial fossil in the field of human origins: Homo floresiensis a k a the Hobbit. Scientists found bones of a diminutive hominid on the Indonesian island of Flores, and estimated that it lived there as recently as 12,000 years ago. It stood about as high as a normal three year old human child and had a brain the size of a chimpanzee’s. But its bones were also found with stone tools.

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Grandma Manimal

Posted on by Lori Jia

Nothing gets the blood boiling like a manimal. For many people, the idea of breaching the human species barrier–to mingle our biology with that of an animal–seems like a supreme affront to the moral order. In his January state of the union address, President Bush called for a ban on “creating human-animal hybrids.”

These so-called chimeras, according to their opponents, devalue humanity by breaching our species barrier. “Human life is a gift from our creator, and that gift should never be discarded, devalued or put up for sale,” Bush declared.

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