Colossal Biosciences’ new and wonky concept of “de-extinction” won’t work

After getting hammered by scientists for implying that their company was going to bring back extinct species, Colossal Biosciences has constantly been tinkering with its concept of what “de-extinction” really means.

First they touted that they were bringing back extinct species. Then, after some criticism, they admitted that they were not really resurrecting extinct species, but merely making genetic changes in existing species so they’d resemble extinct ones (e.g., the “dire wolf”, the moa, and the mammoth).  But then Colossal’s Chief Scientific Officer Beth Shapiro apparently realized that that wasn’t going to excite the public (and potential investors), so she simply said that, in the company’s view, a species that resembled an extinct species to an unspecified degree could be considered that extinct species.  In other words, she was adopting a relaxed view of the “morphological species concept.” To anyone with more than a handful of neurons, though, that won’t fly, as 15 genetic dire-wolfish tweaks in a coyote genome does not a dire wolf make.

Remember that Colossal predicted that they would have woolly mammoths on the ground by 2028 (they have changed that to 2030), and now, despite the absence of relatives and surrogates who could nurture or gestate tweaked species, they are saying they’re also going to “de-exinct” the flightless moas of New Zealand as well as the thylacine, the extinct “marsupial wolf” whose last member died in 1936.  Even if they were able to change tinamous to make them look more like moas, or numbats to resemble thylacines (good luck with that!), or elephants to resemble woolly mammoths (again, much luck needed!), they would not be bringing back extinct species, but only creatures superficially similar to extinct species.

I’ve discussed the four main problems with Colossal’s program in an op-ed in the Boston Globe. In short, they are the bogus claim that extinct species are being resurrected (and the impossibility of doing so), the diversion of money from real conservation needs of real species, the ethical issues of creating animals destined to be homeless and not adapted to the wild (Colossal’s program includes restoring these animals to ecosystems), and the likelihood that these shenanigans will give science a bad name by promising scientific advances that won’t be realized.

I am not denigrating the technical advances in multiple gene-editing that will surely come from Colossal’s endeavors, but criticizing their unlikely-to-be-realized promises, encapsulated in the title of my Globe piece, “De-extinction is a colossal disappointment.”

But here I want to concentrate on the second problem: Colossal’s claim that “de-extinction” involves not just bringing back simulacrums of extinct species (yes “simulacrums” is a proper plural), but also putting them in their original habitats. Have a look at how Colossal now conceives of “de-extinction” on its ever-changing website.  There you can read this (bolding is theirs):

Yesterday’s definition: de-extinction by the book:

Wikipedia officially defines de-extinction as: “the process of generating an organism that either resembles or is an extinct species.”

While this simplistic definition of de-extinction may suffice for Wikipedia and the world, it is neither accurate nor comprehensive enough to describe our mission.

For Colossal, de-extinction is not just about making an organism that is or resembles an extinct species. It’s about merging the biodiversity of the past with the innovations of the present in an effort to create a more sustainable future.

What does that mean? They explained it by coining a new term:

functional de-extinction

The process of generating an organism that both resembles and is genetically similar to an extinct species by resurrecting its lost lineage of core genes; engineering natural resistances; and enhancing adaptability that will allow it to thrive in today’s environment of climate change, dwindling resources, disease and human interference.

And they go on to expand upon it:

We are developing core technologies for the preservation of all species.

We are elevating expectations for de-extinction by rebuilding species to be stronger and more resilient than their predecessors.

We are repositioning once extinct species to thrive in today’s changing climate and ecosystem.

It’s absolutely clear that the de-extincted species are supposed to be placed back in the wild (“rewilding”; see below).

But if you think about it for a nanosecond or two, you realize that if you want to produce animal simulacrums that will thrive in a natural habitat, like faux woolly mammoths restored to the tundra, you need to produce more than just superficial changes in appearance. These animals had adaptive behaviors and physiologies, the former instantiated in the animals’ brains, and the latter in their bodies. And both behavior and physiology of extinct species are, even if coded in a fossil genome that we can read, unidentifiable. So these goals, to me at least, seem unattainable:

The “core genes” shown on that page to tweak an Asian elephant into a viable “woolly mammoth” that can “thrive in today’s changing climate and ecosystem” (presumably the tundra), include those involved in only six traits:

Domed cranium (the connection of this with adaptation is nebulous; it may be there just to make elephants look more like mammoths)
Longer tusks
Smaller ears
Shaggy coat
Variable levels of body fat
Longer fur (isn’t this the same as “shaggy coat”?)

And only one of these traits, “more body fat” is a physiological trait, but the mammoth-ian gene for fat metabolism, when put into the infamous “woolly mouse”, was not shown to affect cold tolerance. And of course there are all those thousands of genes affecting behavior (maternal behavior, foraging, social behavior, mating, migrating. avoiding predators and so on) and physiology (eating and digesting the right foods, living in modern, warmer environments, etc.) that are not considered “core genes”. But changing those genes to forms possessed by extinct species is essential in allowing even simulacrums of those species to survive in the wild.   And make no mistake about it: “rewilding” is a major goal of Colossal. As that page notes:

The science of de-extinction finds peak application through the processes of reintroduction and revitalization – known as rewilding. The concept is simple: return extinct animals to their original habitats so they can begin reversing the detrimental effects of climate damage. Thus, by leveraging genetic engineering, Colossal will be able to rewild vital landscapes, ending the threat of extinction faced by many species currently in existence, having a positive net effect on carbon offset, and supporting the local economies dependent on the targeted, affected habitats.

In the case of the cold-tolerant elephant mammoth hybrid specifically, rewilding equates to the reintroduction of a large cold-tolerant mammal grazer to the tundra regions of the Earth. By stirring up the ice-locked surfaces of the landscape, stomping out thin, low-oxygen trees, and exposing healthy, carbon-trapping grasses, Mammoth populations will begin immediately restoring the tundra’s role as a climate protector and balancer of greenhouse gases.

The reversal of climate damage involves claims, for the resurrected “mammoth”, that the reintroduced elephants-in-fur-coats will mitigate global warming. This is how it’s supposed to happen (from Colossal):

Re-establishing an ecosystem filled with grasslands will help to create a cycle that prevents the thaw and release of stored greenhouse gases within the arctic permafrost. With cold-tolerant elephant mammoth hybrids grazing the grasslands and roaming comfortably during the winters, they scrape away layers of snow, so that the cold air can reach the soil. This also allows grasslands to thrive and since they’re lighter than forestry, the snow won’t melt as quickly. Making way for another benefit – a surface that reflects the Sun’s radiation.

Good luck with that! How are we going to get herds of “elephant mammoth hybrids” (here they admit they aren’t creating woolly mammoths) roaming the tundra?

Now the page claims other benefits of genetic tinkering, including the ability to bring back species that are going extinct or have gone extinct within recent years, but those endeavors have their own problems, I have no time to go into that.