There's been a lot of talk about de-extinction lately. There's one guy in Russia who wants a herd of mammoths. Some people would like to bring back the passenger pigeon.
The obvious question is - should we?
Elephants are rare enough to make one question how ethical it would be to use a band of female elephants to produce mammoth calves...and really, would you get a mammoth or a furry elephant? We can restore the genes, but not the culture, and pachyderms are intelligent enough to have culture.
And for everyone who wants the passenger pigeons back... (There's a great short story on precisely this subject in the July 1993 Analog - "Johnny Birdseed" by the awesome Stanley Schmidt).
And, of course, what's next?
If we can recreate mammoths, passenger pigeons, the dodo...then the next step is to make entirely new species. In science fiction, we sometimes predict the creation of entirely new human species. Lois McMaster Bujold's Quaddies - humans adapted to free fall and with hands instead of feet - come immediately to mind (she also created genetically engineered hermaphrodites and a society that practices both genetic engineering and selective breeding to "improve" humanity). So do Alastair Reynolds' even more extreme Denizens - from human stock, but anaerobic and capable of surviving in the oceans of Europa. The list goes on.
Could we create a new humanity? Should we? Is it playing god, or is it the ultimate destiny of any truly intelligent, technological race to take charge of and steer our own evolution? Can our wisdom catch up to our technology?
Do we, even, have a responsibility to restore those species we ourselves have destroyed?