As some, notably Harvard geneticist George Church, are proposing to do, via DNA sequences from mammoths found frozen in permafrost:
What they are doing is making a genetically modified Asian elephant by inserting into its genome a maximum of sixty mammoth genes that they think differentiate the modern species from the extinct one: genes that involve hairiness, cold tolerance, amount of fat, and so on. What they’d get would be a genetic chimera, an almost entirely Asian elephant but one that is hairier, chunkier, and more tolerant of cold. That is NOT a woolly mammoth, nor would it behave like a woolly mammoth, for they’re not inserting behavior genes.
Jerry Coyne, “A mammoth debacle” at Why Evolution Is True (September 14, 2021)
Well, this raises a number of questions:
If it looks like a woolly mammoth, won’t most people just conclude that it is one? So, in a sense, they will have succeeded.
How do we know how woolly mammoths behaved, relative to elephants? And how, exactly, is their behavior related to their genes? Are there actual behavior genes or a complex combination of factors?
Of course, it all sounds crazy, especially when you get to the “artificial uterus” part. But genetic fundamentalism may not be the strongest argument against it.
This is part of a de-extinction drive. Again, one might want to ask, if extinctions happen due to changed environments, do we know enough to risk interfering with that?
It seems we shall see.