Category: paleogenetics

Colossal reverses course AGAIN, now says that it did indeed bring back the dire wolf

May 25, 2025 • 9:30 am

I’ve posted her often about the follies of “de-extincting” animals like the dire wolf, dodo, and woolly mammoth, culminating in a Boston Globe op-ed on May 1.  I’ve been quite critical of de-extinction claims, particularly those of Colossal Biosciences, which claims to have de-extincted the dire wolf, is on track to de-extinct woolly mammoths by 2028, and says it’s working on bringing back the dodo and the thylacine. My Globe op-ed explains four major problems with Colossal’s program. The first was this:

First, and most important, “de-extinction” is not de-extinction. The company says its claim to have de-extincted the dire wolf is legitimate because its edited pups meet some of the criteria for species “proxies” established in 2016 by the International Union for Conservation of Nature. But that claim is bogus. What Colossal has made is simply a gray wolf with a handful of genetic tweaks changing its size and color.

In the case of the mammoth, what we (may eventually) have is an Asian elephant with a handful of mammoth traits. And a handful of mammoth traits does not a mammoth make. I can paint my Ford Taurus bright red and even attach the Ferrari insignia to its hood, but it’s still a Ford Taurus, albeit with a handful of Ferrari traits. The Ferrari-ness of a Ferrari permeates every feature of a Ferrari’s engineering, just as the mammoth-ness of a mammoth permeates every feature of its biology. We know from ancient DNA studies that mammoths differ from Asian elephants at 1.4 million sites along its DNA, yet Colossal plans to mammoth-ize only a tiny fraction of these. Victoria Herridge, a mammoth expert, has described Colossal’s “mammoth” as nothing more than “an elephant in a fur coat.”

I am of course not the first scientist to point this out. Several, including Tori Herridge and Adam Rutherford, have written severely critical takes on Colossal’s claims.  But the mainstream media, by and large, ate up those claims.  Science journals and popular-science magazines like Science and New Scientist, however, did publish trenchant criticisms.

I believe Colossal was stung by these criticisms, which I’m sure they didn’t anticipate—though they should have. The company pushed back, but eventually, in an article in New Scientist (see below and my post), quoted Colossal’s chief scientific officer, evolutionary biologist Beth Shapiro, as finally admitting that they really didn’t produce dire wolves, but grey wolves with a handful of edited genes that supposedly made the tweaked canids look more like ancient dire wolves.

Click below to see  Colossal’s partial retraction, which is also archived here:

Here’s how Beth Shapiro walked back the dire wolf de-extinction claim:

Well, yes, they had said they were dire wolves.  As the NYT reported on May 11:

The resulting animals [the gene-edited solves] were larger and fluffier and lighter in color than other gray wolves. The company’s chief science officer, Beth Shapiro, says this is enough to make them dire wolves, if you subscribe to the “morphological species concept,” which defines a species by its appearance. “Species concepts are human classification systems,” she told New Scientist, “and everybody can disagree and everyone can be right.”

Here’s Shapiro saying the same thing in a Bluesky post:

Oy!  Everybody can disagree and everyone can be right!  All must have prizes!  She says that Colossal chose to call them dire wolves because they look like dire wolves. That’s a highly watered-down version of the morphological species concept, one of the alternative species concepts that Allen Orr and I criticized in our book Speciation (see chapter 1 and Appendix). But the most trenchant and humorous criticism of using this concept to rescue Colossal’s claim also came from the NYT piece:

A lot of people disagreed. Calling the pups dire wolves, wrote the evolutionary biologist Rich Grenyer, is “like claiming to have brought Napoleon back from the dead by asking a short Frenchman to wear his hat.”

LOL.

In fact, we have no idea whether the three animals produced by Colossal even look a lot like the extinct dire wolf. For one thing, Colossal used mutations known in wolves and dogs (not taken from the dire wolf genome) to make the three living individuals white.  We don’t know if dire wolves were white, and some think they were reddish-brown, which seems more appropriate given that they didn’t live in the Arctic. (They lived in woodlands in the tropics and temperate zone.) And, as I’ve emphasized at great length, they can’t give the de-extincted animals the brains of the original species, for we don’t know which genes control the brain differences, much less what the brain differences were. Absent that ability, no de-extincted animal can behave like its model—something crucial if you want, as Colossal claims, to restore these animals to their “original” habitat.

But where we were as of yesterday was that Colossal, via Beth Shapiro, had finally admitted that they had not produced dire wolves but genetically tweaked gray wolves (of the 20 tweaks, five came from mutations in dogs and gray wolves, not from the dire wolf genome).

Now, however, they’ve walked it back again!  The tweet below shows a statement sent to New Scientist by a spokesperson at Colossal. Jacob Aron is the magazine’s news editor and he, like all of us, is now deeply confused. Colossal says that yes, they DID make dire wolves:

Colossal has sent us a statement, which we've added to the story. I don't feel the situation is any clearer…

— Jacob Aron (@jjaron.bsky.social) 2025-05-24T11:14:21.057Z

The New Scientist article now has this “correction:

Yep, let me put that in big letters: “WITH THOSE EDITS, WE HAVE BROUGHT BACK THE DIRE WOLF”.  And even using the concept of “functional de-extinction” is bogus, for they know nothing about the function (behavior, etc.) of the dire wolf.  All we know is that we have three white-colored gray wolves that may have bigger heads than did gray wolves when the trio grows up.  But 20 genetic tweaks is a teeny, tiny fraction of the thousands of differences between the extinct and the de-extincted creature, including the missing differences in brain structure.

The impression I get is that Colossal is now in PR chaos, stung by criticisms made by scientists and quoted in the press. They are desperate to say that they really have de-exincted animals despite the fact that all they have are three white canids, each with 15 DNA letters changed from gray wolf code to code taken from the dire wolf. Really, by any stretch of the imagination these are not members of a resurrected species. And the more Colossal opens its yap, now contradicting itself twice, the less respect I have for it.

After Shapiro admitted that Colossal hadn’t resurrected dire wolves, one of my colleagues posted this on Facebook:

I’m OK with this…I like it when scientists admit that they were wrong, or over-stated something. Although the initial press release was misleading at best, I’m glad that they clarify that these were not really Dire Wolves.

Sadly, they now say that they really are dire wolves. I’ve informed said colleague about the update, and we’ll see what he/she says.

h/t: Matthew

Human Phylogeography

February 23, 2019 • 11:33 am

by Greg Mayer

For the spring semester, my colleague Dave Rogers and I are teaching a seminar class entitled “Human Phylogeography.” Phylogeography is the study of the history of the genetic variation, and of genetic lineages, within a species (or closely related group of species), and in the seminar we are looking at the phylogeography of human populations. DNA sequencing now allows a fine scale mapping of the distribution of genetic variation within and among populations, and, remarkably, the ability to sequence ancient DNA from fossil remains (including Neanderthals). The seminar is based primarily on a close reading of David Reich’s (2018) Who We Are and How We Got Here (published by OUP in the UK).

A Krapina, Croatia, Neanderthal woman, photo by Jerry.

Although rarely under that rubric, human phylogeography has been a frequent topic of discussion here at WEIT, by Jerry, Matthew, and myself, including our several discussions of Neanderthals (or Neandertals) and Denisovans. So it may be of interest for WEIT readers to follow along. Below the fold I’ve placed the course syllabus, which includes the readings, and links to many newspaper articles of interest, and online postings, including many here at WEIT, and also from John Hawks Weblog, a site we’ve recommended on a number of occasions when discussing human evolution. (The newspaper links appear as images; just click to go to the story.) We just finished our third meeting, and I’ve been quite impressed by the students’ discussion and writing. We’re fortunate to have some students from anthropology or with some anthro background.

Please read along with us, or browse what seems interesting below. If you have questions or comments, post them here, and I’ll be looking in.

Continue reading “Human Phylogeography” →

Svante Pääbo gives a good public lecture on Neanderthals, Denisovans, and other relatives of modern humans

October 26, 2018 • 12:30 pm

I think most readers know about Svante Pääbo and his work on “paleoanthropology”: the study of the evolution and ancient movements of H. sapiens through analysis of “fossil DNA”.  His most famous work is on the genetics of Neanderthals, a subject in which I’ve recently become interested.

Pääbo’s work been extended to Denisovans and other previously unknown human groups, and what we’re learning is that even in H. sapiens the evolutionary tree is convoluted and interconnected. This does not, by the way, vindicate the thesis that evolutionary trees are wrong, or can’t be accurately determined. Despite that, there are some fossil individuals so genetically heterogeneous that they can’t be slotted into one group or another (see below). Our relatives were “mixing” quite promiscuously when they met.

In this remarkably clear lecture (h/t: Matthew Cobb), which proceeds chronologically through the scientific findings, Pääbo lays out the genetic data produced by his lab. (This is the award lecture accompanying Pääbo’s 2018 Nierenberg Award for Science in the Public Interest, given on October 3 of this year.)  There’s some freaky stuff in here, including an individual that appears to be an F1 (first-generation) hybrid between a Neanderthal and a Denisovan (about 32 minutes in).

36 minutes into the lecture, Pääbo summaries the contribution of Neanderthal and Denisovan genes to modern humans, including the possibility that a gene we carry from Neanderthals that now gives us a higher propensity for type 2 diabetes could have been an allele that helped Neanderthals deal with starvation. Similarly, Denisovans have bequeathed to modern Tibetan populations a gene that helps deal with high altitude.

In fact, there are at least a dozen “archaic” genes from Neanderthals and Denisovans that remain in our genomes and are associated with disease, perhaps because they don’t function well in the genetic backgrounds of modern humans. (There’s evidence that some of these have been selected against.) At the end, Pääbo discusses the genes in modern humans not present in Denisovans or Neanderthals; the idea here are that these human-specific genes (there are 87) that makes us “important” and “special”. I’ll let you watch those last 12 minutes on your own. There are four minutes of questions at the end.

All in all, this is a superb introduction to the complex and always-changing picture of our relationship to recent hominin relatives. If you watch it, and you should, you’ll be absolutely up to speed on human paleogenetics. But, as Steve Gould used to say, when he lectured on human evolution at Harvard each year, his first act was to throw out all his notes from the previous year’s lecture.