A couple of nights ago I caught the end of a TV 'news' item about mammoths. Molecular biologists have managed to sequence the mammoth genome - the next thing, said the reporter breathlessly, will be bringing mammoths back to life...
Only it's not that simple. And Olivia Judson has just written an excellent piece explaining why not. For a start, we're talking a fragmentary genome here. Mammoths have been extinct for 10,000 years & over that time their DNA has degraded. So it's all in bits, rather than complete chromosomes. So scientists would need to reconstruct the mammoth chromosomal organisation as well.
Then there's the problem of how to get your baby mammoth. Easy, said the TV story - simply insert the mammoth DNA into an elephant egg, place that into a female elephant's womb, & bingo! baby mammoth. Except that mammoths & elephants aren't all that closely related, & we already know that this sort of cross-species reproductive tweaking is extremely difficult. And since elephant pregnancies last 22 months, you'd have a long wait to see what you got at the end. That's not even taking into consideration the huge number of eggs, embryos, & host mothers you need to get even one successful pregnancy.
But there's another, & I think more important question - mammoths are extinct. Even if we did manage to bring one back, using this technology, it would always be no more than a curiosity. The environment has changed since the time of the mammoths, & their ecological niche is gone. But what about all those other species currently on the brink of extinction? We still have the opportunity to do something about that. Wouldn't the money that would be needed to bring an individual mammoth back be better spent on saving the world that we have? Better to try to save polar bears now, than worry about resurrecting them later.