Readers and correspondents are asking me what i think about the just-revealed “de-extinction” of the dire wolf by Colossal Biosciences, and the firm’s attempt to bring back the woolly mammoth, too. I don’t want to write much about this now because I’ve put up a few posts about the mammoth before, and Matthew has expressed similar sentiments in his book As Gods: A Moral History of the Genetic Age. Further, I am writing my take for another venue, so I will just say this about the genetics of the de-extinction efforts so far:
My general sentiments are these: attempts to bring back extinct species as outlined so far are not only scientifically misguided, but are journalistically mis-reported by the press. That is, the press is, by and large, distorting what has been done scientifically, pretending that an animal with only a few cosmetic gene edits is actually identical to an extinct species. Further, Colossal seems happy enough to let this misconception be widely reported (to be fair, there are some decent articles about the science of de-extinction, and I’ll link to a few below).
The main problem, as I said, is the pretense that changing a living species by editing just a handful of genes (20 max so far) to get something that looks like the extinct “dire wolf” is not the same thing as re-creating a dire wolf. That species undoubtedly had hundreds or thousands of genetic differences from the gray wolf, including genes affecting metabolism and behavior—genes that we do not know. Further, control regions of genes, which are outside protein-coding regions, undoubtedly are involved in differences between extinct species and their relatives. But we don’t know where these regions are and so cannot use them for genetic editing.
All of this means that, in my view, de-extincting species is a cosmetic rather than a serious genetic project, designed to produce gee-whiz animals to entertain rich people and to wow children. Such animals, especially the highly touted de-extincted mammoth, which mammoth expert Tori Herridge calls “an elephant in a fur coat”, would certainly not survive in their original habitat. Further, proponents’ claims that de-extinction would be a fantastic conservation effort , and could even mitigate global warming. are totally unsupported speculations.
There are two such efforts that have received all the press: the de-extinction of the woolly mammoth and of the dire wolf; the latter effort has produced some pups, but they are not dire wolves. We will never see woolly mammoths, though Colossal promises that they’ll be stomping about in three years!
Mammoth (see my website posts above) There are many reasons why this project is a non-starter. The evidence that it is feasible rests solely on the production of “woolly mice,” which are mice that have had 8 edits in only 7 genes (remember, mice are easier to work with than elephants!). Only two of the genes that were changed were edited in a way to conform to known mammoth genes. The rest are simply using mouse mutants known to affect hair texture, color, and waviness in lab mice. Thus we have a woolly mouse—not anything close to a woolly elephant. Yes, it’s cool to make multiple changes in multiple genes at once, but this is not a new technology. The novelty will be to edit an elephant egg cell in a way that the edited cell can be implanted in an Asian elephant and develop into a woolly mammoth. If you really want something popping out of an Asian elephant that is close to a woolly mammoth, you will never get it. In fact, the whole project seems impossible to me. And the conservation results touted by Colossal–that the re-exincted mammoths, released on the tundra, will keep carbon in the permafrost and not in the atmosphere–are purely speculative.
Dire wolf: Scientists edited a gray wolf stem cell, changing 20 genes. Fifteen of the edited genes were designed from from the sequenced dire-wolf genome (again, sequencing an extinct organism is a feat, but not one developed by Colossal), while five others were taken from known genes that change dogs or wolves (the articles aren’t clear on which genes were used, as Colossal is keeping that secret). The edited cell, as an egg, was placed into a “large dog” to be the surrogate mom, and then extracted via caesarian section (did the dogs survive this procedure?) They get a whitish wolf with some dog or gray-wolf genes, not dire wolf genes. All of the changes are said to affect things like fur color, body size, and tooth and jaw configuration–traits that differentiated the dire wolf from the gray wolf. As I noted, we wind up with a gray wolf (and remember, domestic dogs are descended from gray wolves, and can even be considered gray wolves, as they mate with each other and can produce fertile hybrids); we get a gray wolf with a couple of changed traits to make it look like what we think the dire wolf looked like. (We are not sure, for example, that the dire wolf had white fur.)
Neither the mammoth nor the dire wolf results are published in a peer-reviewed journals, though the woolly mouse experiment has been languishing on bioRΧiv for a while but hasn’t been published.
Here are some links, most but not all of them pointing out problems with de-extinction projects:
Colossal’s explanation of the mammoth project. (Note that they also want to de-extinct the dodo and the thylacine, or marsupial wolf.)
Colossal’s account on the dire wolf result.
Nature paper by Ewen Calloway on why the woolly mouse isn’t a credible step towards a woolly mammoth.
Nature paper by Tori Herridge explaining why she turned down a position as advisor to Colossal on the mammoth
Article in Ars Technica by Nitin Sekar, WWF authority on conserving the Asian elephant, explaining why “Mammoth de-extinction is bad conservation.”
Guardian paper by Adam Rutherford explaining why trying to de-extinct the Woolly Mammoth is not only unethical, but impossible.
NYT article by Carl Zimmer on the dire wolf, a good summary and not nearly as critical as his Bluesky post below.
New Yorker article by D. T. Max on the dire wolf, somewhat windy and credulous (archived here).
Article in the MIT Technology Review by Antonio Regalado: “Game of clones: Colossal’s new wolves are cute, but are they dire?”
Tweets and posts:
Tori Herridge’s posts on both Twitter and Bluesky are an informative and hilarious critique of the woolly mouse/mammoth projects. Get started with this one if you’d like (it’s a thread):
[though as an aside, honestly Colossal missed a trick not going for the Fgfr1/2 double mutant — I mean, have you seen a more mammothy-mouse?!]*MAMMOUSE KLAXON*www.nature.com/articles/s41…
— Tori Herridge (@toriherridge.bsky.social) 2025-03-05T00:20:55.808Z
Journalist Asher Elbein and a commenter on the misleading Dire Wolf.
Here Carl Zimmer points out that Colossal’s dire wolf is not a dire wolf. This is a bit more frank than his NYT article!
It's not a dire wolf. It's a gray wolf clone with 20 dire-wolf gene edits, and with some dire wolf traits. And here's my story! Gift link: http://www.nytimes.com/2025/04/07/s…
Adam Rutherford (read his Guardian article on mammoths above) is particularly critical of the Dire Wolf project. I love the first tweet asserting that journalists who don’t do due diligence are making people stupider. That’s true, and it also makes people misunderstand (and possibly eventually mistrust) science:
Public service announcement. They are not Dire Wolves. They have 20 single letter changes in their entire genomes. I’ve done shits with more mutations. Every time journalists write up a Colossus press release, They are making people stupider. Client journalism by a ridiculous company.
— Adam Rutherford (@adamrutherford.bsky.social) 2025-04-07T20:02:25.283Z
GODDAMIT. IT’S NOT A RESURRECTED DIRE WOLF. 20 edits in 19,000 genes. IT’S NOT GOING TO AID CONSERVATION. EVERY WRITE UP THAT SWALLOWS AND REGURGITATES THIS GUFFERY WOLFSHIT IS DOING PR FOR A FUNDING ROUND.
— Adam Rutherford (@adamrutherford.bsky.social) 2025-04-08T12:05:49.778Z
Caveat emptor!
Oh, and for fun, here’s the Secretary of the Interior tweeting about how we shouldn’t worry so much about endangered species and pay more attention to “de-extincting” species. But of course “de-extincting” isn’t going to do squat to keep existing species from waning. Burgum is off the rails here, entranced by the dire gray wolf.
According to the New Yorker article, Colossal is now valued at over 10 billion $mackers. Theranos has some competition now.
I think Theranos is dead, defunct, and kaput, singing with the Choir Invisible. As far as I know, it is an Ex Company.
I love your nod to Monty Python! I laughed out loud. Thank you, Professor Ceiling Cat, for adding some humor to my day.
++1!
I was going to ask where was this company getting the money to do this stuff…. Thanks for the heads up. Apparently Colossal Biosciences (you have to give them credit for a great name) is a private company that will “let” you invest in them. Something Darwinian is going on here for sure.
Something Darwinian and/or P.T. Barnumian is going on here. Editing small portions of great numbers of genes is like altering a canines ears or tail in order to make it look more like a horse or bear –
no matter how you splice them.
Thanks. I knew that this would be coming from you.
This whole “de-extinction” project seems….dire.
Heh.
Oe at least very difficult.
The Perri et al. (2021) paper on Dire Wolf DNA shows that they weren’t even particularly closely related to modern grey wolves, but rather a completely separate canid lineage that evolved in isolation from the ancestors of modern wolves. Given that degree of separation, the claim that you can re-create them by changing just a handful of nucleotides is ridiculous. Nobody knows what a living Dire Wolf looked like. For all we know they could have been as distinctive in appearance as modern African wild dogs (Lycaon pictus), which could never be confused with grey wolves. The fact that these genetically-modified pups are a bit chunky and have white fur is irrelevant.
https://www.nature.com/articles/s41586-020-03082-x
The press is all over this (and the Woolly Mammoth, the Woolly Mouse, the Dodo, the Thylacine, etc.) De-extinction certainly fascinates the general public. I looked trough your annotated list of citations which, except for Zimmer’s at the NYT, seem to be rather critical. (I haven’t read them; I’m just going by your annotations.) What I’m wondering is whether there is any paper that addresses the various issues raised here and elsewhere point by point. It would be interesting to read how the proponents answer the multitude of questions, perhaps the most obvious of which is that de-extinction doesn’t actually recreate the extinct creature in its totality.
There is a list of papers that don’t mention any problems at all, but I find that to be bad journalism. You can read the Colossal links to get an uncritical view. And no, there is no refutation of the points i know of except for some Colossal flaks saying, “Yes, we KNOW that it’s not a complete Dire Wolf but who cares?” and things of that ilk.
There are plenty of criticisms but a paucity of responses by proponents. Their enthusiasm outweights their critical faculties.
I suppose that the proponents will continue to embrace the enthusiasm to keep the momentum—and the funding—going. I’m of two minds on this. One mind thinks that some useful knowledge will come out of this work. The other mind doesn’t like how the researchers seem not to be addressing the problems head on. I can’t help but think that the proponents are reluctant to hold a full conversation about the problems out of concern that doing so will dampen the public’s enthusiasm and the willingness to fund the research.
Thank you.
Maybe we should come up with a “scientific definition” of “De-extinction” so that we can qualify the degree of marketing in these press releases.
Apparently such a definition does not exist ???, what about:
“De-Extinction is the process of recreating a genetically and functionally IDENTICAL population of organisms that belong to a species previously declared extinct, such that the revived POPULATION is capable of sustaining itself in the wild as a self-regulating biological entity.”
I have started to refer to these constructs as “artificial mimics”.
How about “transmammoths”, etc. ?
Good!
Excellent suggestion. I think this name summarises very efficiently the main points of criticism.
I hope the Trump administration isn’t drawing the wrong conclusions (that they can recreate extinct species). Quote:
“The Endangered Species List has become like the Hotel California: once a species enters, they never leave. In fact, 97 percent of species that are added to the endangered list remain there.”
Is that true? I have no idea.
If so it is probably as they have suffered habitat loss. The best thinking these days suggests conserving habitats rather than aiming at species individually – though some, like elephants, wolves, beavers (humans?) are ‘keystone species’ that change environments & increase biodiversity. The reason Bison proliferated in such vast numbers in North America until the introduction of the rifle, was because humans &/or the end of the ice age (depending on who you ask) had wiped out the competition.
https://en.wikipedia.org/wiki/List_of_endangered_animals_of_North_America
I see a lot of sub-species on this list & not all from the USA – blue whale for example (US waters)…
You could introduce the lion & the cheetah, the camel etc as approximations of their extinct relatives, but that ain’t going to happen anytime soon!
It is hard to get something listed nowadays. It has to be really in trouble to get through the barriers put up by politicians of both parties. So it is not surprising that those species have mostly not recovered, given the loss of breeding habitat, destruction of tropical wintering grounds for migrants, pervasive use of pesticides, incursions of incredibly destructive invasive non-native species like fire ants, etc. Only a few very charismatic species have been able to recover, because of public attention. The Bald Eagle, Osprey, and Peregrine are good examples of recovering species, mostly due to the outlawing of DDT in response to the public outcry following Rachel Carson’s wonderful and evocatively titled book, Silent Spring. Most endangered species do not attract that much attention.
Thanks for the info!
It probably is true — for very good reasons: They haven’t recovered enough to take them off the list!
His comments miss the effing point (naturally).
Instead of trying to resurrect the dire wolf, you could spend your time and express your interest in extinct mammals just as well by hiking around Tasmania looking for fresh new thylacine footprints. Your chance of success wouldn’t be great — but would be better than with the dire wolf resurrection project. After all, the Thylacine has been around somewhat more recently than the dire wolf.
Nice summary thanks.
As soon as I heard this I thought they are certainly a different genus.
Do you suppose Burgum wants to de-extinct Neanderthals?
Get a hold of a Genuine Holy Foreskin© and Colossal can re-resurrect Jesus, who could de-extinct anything he fancied. Slartibartfast might be able to help with those fiddly Denisovan genes.
Question for those biologically knowledgeable: Wouldn’t it be an order of magnitude easier to deextinct Neanderthals than mammoths or dire wolves? Obviously the ethical concerns are immense and I’m not advocating that anybody undertake the project. But I assume that Neanderthal and H. sapiens genes differ less by orders of magnitude than mammoth and Indian elephant genes or dire wolf and grey wolf genes differ.
I have heard that after Neanderthal genomes were sequenced, an enthusiastic scientist told a radio host that if we wished, we could bring the Neanderthals back, provided that some ladies would agree to be surrogate mothers to Neanderthal babies. After the interviews, many women called to volunteer.
If they really want to bring back extinct creatures, then why not resurrect The Moderate Republican?
Who’d want to fund it? Certainly neither the Republican nor Democratic parties.
Thanks for this comprehensive post.
This “de-extinction” stuff sets me off — I suppose one might say I’m, uh — triggered. It’s just biotech bros muscle flexing gee-whiz technology with no ecological context.
This here — Burgum is off the rails here, entranced by the dire gray wolf.
— is spot-on. And,gollly, don’t want to be too political, but that’s exactly what one might expect from the Trump administration, getting on to the next step of: we’ll tear up endangered species list because anything extinct can be “brought back”. Bah!
Also, re “totally unsupported speculations” and “purely speculative” — kudos for very polite language. I’m want to learn to follow that example, though my tongue bleeds.
Thank you very much Jerry for this objective assessment of this story. We love your website!
And, of course, asshole Republicans are proposing to get rid of ESA protection of the Gray Wolf and, naturally, get rid of the ESA completely. Why would anyone want any wildlife that can’t be turned for a profit?
From a link in the Carl Zimmer article:
In my old homeground, Minnesota, Jim Brandenburg (November 23, 1945 – April 4, 2025), the great wildlife/outdoors photographer, who just passed away, noted that, living in the woods, outside of Ely, Minnesota, he had a familiar pack of wolves that he would see frequently around his house. The Gray Wolf has been delisted in Minnesota (which may have been appropriate at the time, based on numbers) and one hunting season was run a few years ago.
That one hunting season was closed early because too many wolves were killed in just a couple of days. Since then, he (Brandenburg) never saw or heard wolves around his house anymore. Sadly, right to the end of his life, it seems. These are the very predictable consequences of delisting and hunting.
I was lucky enough in January 1982, while winter camping in the Boundary Waters Canoe Area Wilderness off the end of the Gunflint Trail (yes, it was damned cold!) to see a wolf walk across the lake we were camped on in the predawn light, a sight I will never forget.
https://jwbliliephoto.net/PandJ-Family/OldMN2/000_1982/1982-01%20BWCA%20Winter%20Camp%20Class%20228%20Dawn.jpg
https://jwbliliephoto.net/PandJ-Family/OldMN2/000_1982/1982-01%20BWCA%20Winter%20Camp%20Class%20218%20Rob%20Levine.jpg
https://jwbliliephoto.net/PandJ-Family/OldMN2/000_1982/1982-01%20BWCA%20Winter%20Camp%20Class%20220.jpg
I’m not sure what the point of the dire wolf experiment is. Perhaps just to perfect techniques for widening the gene pool for at risk species which have low genetic diversity. The notion that the dire wolf has been brought back from extinction is ludicrous, for reasons you state, but also for the fact that it’s 12,000 year old habitat no longer exists. Whether a true dire wolf could survive now is debatable and doubtful.
WaPo casts shade on the effort and also notes the value of the company and amount of funding rec’d this year.