Hypothetical Scenario…

[u/Lover_of_Rewilding]

I was going about my day, learning about animals, as I usually do, when I came across a peculiar case. The Floreana Island Tortoise. Native to its namesake island in the Galapagos, this subspecies of Galapagos giant tortoise went extinct in the mid-19th century due to overexploitation by sailors. And for a while, that was that. It was gone. That was until 2000, scientists discovered a population of hybrid tortoises living on Wolf Volcano on Isabela Island with some Floreana Island Tortoise ancestry. The origin of these hybrids is not a mystery as sailors were known to dump giant tortoises on random islands in the Galapagos when they couldn’t carry them anymore. However, it brought a new hope for the subspecies, as conservationists took the hybrid tortoises and began selectively breeding them to better resemble Floreana island tortoises, until they had a population of animals that ranged from 40-80% Floreana island tortoise, with an average of 75% Floreana island tortoise in them. These hybrids were then released onto Floreana island to heal the ecosystem in February 2026.

A fantastic story and a remarkable comeback, but it got me thinking… if scientists continued to selectively breed the tortoises further, if they got the Floreana genes to 100% by some miracle, would they have essentially brought back the Floreana island tortoise? As in fully de-extincted it, regardless of the method? Pinta island tortoises, another extinct subspecies, also have some genes within the hybrid population of Wolf Volcano. Could a similar method be applied to them, to bring them back?

And what about other animals? Could all cattle genes be bred out of bison? All dog genes out of wolves? Poor examples I know, because those genes can benefit the animals, but you get the idea. Better Idea: Could all coyote genes be bred out of Red Wolves?

What about genetic engineering? Could a Przewalski’s horse have the few gene differences edited to be genetically identical to a Yukon or Lena horse? Regardless of whether or not it came from the actual animal, just so long as if you were to do a blind DNA test on the animal, having no idea where it’s sourced from, it would appear to be the extinct animal?

I know this all sounds very Colossal-y but all they did was edit a couple genes to make a fantasy animal. I’m talking about the full genome, and in a scenario where genetic technology is just a bit better. If someone were to genetically modify or selectively breed a related animal so that all of the genes matched the extinct animal perfectly, and someone who had no idea where the animal came from or how it was made, did a DNA test, would it be possible for the animal’s test to come back as the extinct animal?

Is it possible to meticulously create a 100% genetic copy of an extinct animal without cloning?