Interspecies Sex: Evolution's Hidden Secret?

March 14, 2007

The act of mating with a species other than your own may not be as ill advised or peculiar as it seems.

Recent research indicates that hybridization is not only widespread in nature but it might also spawn many more new species than previously thought.

A growing number of studies has been presented as evidence that two animal species can combine to produce a third, sexually viable species in a process known as hybrid speciation. Newly identified examples include both insects and fish.

This evolutionary process, while known to be common in plants, has long been considered extremely rare among animals.

Animals are generally thought to evolve the opposite way, when a single species gradually splits into two over many generations.

But some scientists now believe that the behavior that has been called animals' sexual blunders could be an important force in their evolution.

"Given the fact there have been several reported cases of hybrid speciation in animals, I think it's possible that's just the tip of the iceberg," said biologist James Mallet of University College London in the United Kingdom.

Mallet said that advances in technologies for decoding genes are only now giving scientists the opportunity to make such discoveries.

Hybrid-formed species are usually extremely difficult to detect because of their close physical resemblance to their parent species, he said.

But today scientists are able to collect the detailed molecular data needed to identify previously unrecognized hybrids.

Fast Evolving Groups

Plenty of opportunities exist for hybrid species to emerge, especially among diverse and fast-evolving groups of animals, Mallet said.

Continued on Next Page >>




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