Do Hybrid Species Have Value?


Hybrid species can occur, in rare cases, when two similar species manage to breed and produce offspring. Scientifically, most of these hybrids are considered "unfit" -- weak, genetically impure, sometimes sterile, and worthless for conservation. For example, zoos often refuse to accept hybrid tigers that have been born of two different tiger species, and conservationists sneer at hybrid creatures like "ligers" (lion-tiger mixes) and "zorses" (zebra-horse hybrids).

Most hybrids are the result of tampering by man, including a new hybrid salamander that spawned a few decades ago in California. But unlike most other hybrids, the cross-bred California Tiger and Barred Tiger salamanders are actually thriving in nature, according to Ben Fitzpatrick of the University of Tennessee.

"I thought I was studying hybrid dysfunction going into this study -- looking at how hybrids go wrong," said Fitzpatrick. "The level of vigor in these hybrids was completely unexpected."

The California Tiger salamander is protected as a threatened species under the Endangered Species Act. The Barred Tiger salamander is not considered in danger, and was introduced to California by fishermen who used it for bait. The two species bred, and Fitzpatrick's study suggests that the hybrids are doing so well that, eventually, all California Tiger salamanders will have at least some Barred Tiger genetic material in their systems.

What does this mean for conservation efforts? Does extra care need to be taken to preserve the "pure" California Tiger from extinction? Does the hybrid get counted as a new species? Do we let the hybridization continue and call it natural selection?

While we deal with these issues, I think we can expect a "Frankensalamander" movie to pop up on the Sci Fi Channel before too long.

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