Black Rhinos. Photo by Bounder.
Inkycircus points to the news that the Western Black Rhino has probably become extinct. We were talking about preservation strategies in what would otherwise have been a management meeting last week. Alan Cann raised the topic about how you would preserve endangered animals when you have few of them. In vivo by cross-breeding them with a similar sub-species or else in vitro by storing their DNA?
We didn’t have a perfect answer. I’m against cross-breeding as a solution. What you would have is a hybrid, so you lose the old species, but it’s not so much that that bothers me. Where would you release the new hybrids to live? The reason the Western Black Rhino has gone extinct is that it lives in a rhino-hostile zone. The new rhinos would run into exactly the same problems unless we could cross-breed them with a kevlar-coated rhino. Otherwise how to you set up and monitor a reserve with sufficient space for rhino to thrive in an affordable way?
That leaves DNA sampling as the solution. That’s not perfect either. There is a common belief that DNA is the instruction book for putting a life-form together. That’s not 100% true. Jack Cohen and Ian Stewart explain it in… umm… What Does a Martian Look Like? (I think). In the case of Human DNA, there’s the material there to build a human, so long as it’s inside a human. The DNA doesn’t contain information like what sort of temperature it should be stored at, or what the uterine surface should be like because it can take those details for granted. Similarly if you have Western Black Rhino DNA in a fertilised egg then do you need to implant it into a Western Black Rhino?
You might get away with a Northern Black Rhino as the mother, but the problem there is that you’re assuming by the time we’re able to release the rhinos again that there’ll be other suitable sub-species that can act as host surviving. It seems more likely to me (the non-biologist) that if you have the DNA, you’ll only have the DNA. It’s a useful record, but it won’t bring the rhino back.