A Blog by Carl Zimmer

Genetically Engineering the Wild

Back in April, I wrote in National Geographic about the provocative idea of bringing extinct species back to life. In the five months that have passed since then, I haven’t spotted any mammoths or saber-tooth lions drifting through my front yard. If “de-extinction” ever does become real, it won’t for quite a while.

What I have seen over the past five months is a new conversation. Part of the conversation has revolved around the specifics of de-extinction. Some people are open to the possibilities of rebuilding genomes and embryos of vanished species. Some people find it a flashy distraction from the real work of fighting the current wave of extinctions.

But the conversation is bigger than mammoths and saber-tooth lions. It makes us think about how much we could–or should–manipulate DNA of wild animals and plants. This question applies not just to extinct species that are gone, but to endangered species that are rolling down the road towards extinction. And with estimates that at least 15 to 40% of species will be effectively extinct by 2050, that road is wide indeed. Is it okay to use genetic engineering to save some of them?

In Nature today, a group of conservation biologists take this conversation much further. They report on a meeting they had this spring in New Mexico to discuss how the changing climate will push some species towards extinction and what can be done about it.

For a few years now, some conservation biologists have argued that we should move species to places where they’re more likely to survive. If Florida is too hot in 50 years for a tree to survive, move the tree to Virginia.

But what if we were to move genes instead? That’s the question that the scientists at the New Mexico meeting considered.

Their conversation was based on the fact that animals and plants have evolved genes that adapt them to their environments. As trees move into drought-stricken plains, natural selection may favor genes that help them conserve their water. When pathogens emerge, natural selection may favor genes that make hosts resistant. If Florida is going to become more like, say, Brazil, then maybe genes from Brazil will help species survive in Florida. (As for what genes we might give the species in Brazil…well, that’s hard to say.)

Farmers and livestock breeders have harnessed genetic variation for centuries. They’ve crossed different breeds to create a combination of traits they desire. Conservationists have sometimes used hybridization as well, to nurture endangered species.

In Florida, for example, the dwindling panther population became inbred, and they had less success producing cubs. Conservationists trucked in eight panthers from a related subspecies in Texas. It’s been a dozen years since this cross-breeding took place, and their genetic pool now has more variation.

Hybridization can be very effective, but it’s also slow and inefficient. It jumbles together lots of DNA in lots of different ways; breeders then pick out the crosses that seem to perform best. In recent decades, genetic engineering has made it possible to move individual genes from one subspecies to another, or even one species to another. It might be possible to move genes into wild species to help them thrive. The scientists from the New Mexico meeting point to gene variants in rainbow trout, discovered earlier this year, that help the fish survive in warm water. Those variant could be inserted into other trout that are going to be threatened by rising river temperatures.

The scientists call wildlife genetic engineering “facilitated adaptation.” While they’re ready to give it a name, they don’t want to launch into it without a lot of consideration, however. They want to make sure facilitated adaptation doesn’t cause harm to species that are already on the brink of extinction. Genes often carry out more than one function, and so even if an imported gene has one beneficial effect, it might have others that are dangerous.

The scientists also worry that facilitated adaptation might sap the energy for fighting the causes of today’s extinction crisis. If scientists tell us we can just engineer penguins to live in warm temperatures, then who needs to do anything about climate change?

Even if we stopped warming the planet tomorrow, though, endangered species would still face other threats, some of which genetic engineering might help. We humans move pathogens around the planet, bringing new diseases to new places. A fungus from Europe has killed millions of bats in the United States and show no sign of slowing down. If scientists can determine why bats in Europe don’t die of the fungus, they might be able to insert their gene variant into American bats and make them resistant.

And if this seems like wishful thinking, consider the case of the American chestnut. As I wrote on the Loom, another fungus has nearly annihilated the tree. Fungus-fighting genes from other plants are now bringing it back.

I’ll be very curious to see how this new stage of the conversation plays out in weeks to come. (Feel free to leave your thoughts on the comments below.) But I also hope it doesn’t veer over ideological guard rails.

Opponents may argue that the very act of moving genes from one organism to another is a violation of nature’s diversity. But this is a romantic, pre-genomic view of life. Genes have flowed from species to species for billions of years.

Some supporters of genetic engineering may consider this an easy fix for our extinction crisis. But for many species, genetic engineering won’t help, I expect. You can’t tweak an elephant’s gene to make it bullet-proof. And even for those species that could be helped, scientists know precious little about the genes that could help them. Scientists have started to gather together what little they know about life’s genetic diversity, but they have only started. And unfortunately, for a lot of species, they’re running out of time.

7 thoughts on “Genetically Engineering the Wild

  1. I do fear the eventual consequences if facilitated adaptation works. We could increase the development of unique wilderness for human usage while continually adapting species to a more generalized but shrinking habitat (all while still feeling good about ourselves). I want more wilderness, not less.

    And I think there’s good arguments for doing what we can to save species today or in the near term, if we have the tools. I don’t think the potential unintended consequences to wilderness or climate of the successes of facilitated adaptation match the moral failure of allowing preventable extinctions to occur (though if we’re not also conserving habitat we’re only delaying the inevitable).

  2. “…this is a romantic, pre-genomic view of life. Genes have flowed from species to species for billions of years.” You did a really nice job of swiftly undercutting your credibility right there — all it took was one sentence and two links! Interesting how you referred to HGT in the context of plants and animals like it’s a totally normal and well-studied phenomenon. Those who think otherwise — oh, silly romantics! And yet… the studies you link to are about prokaryotes and a preliminary hunch about butterflies. *CoNfUsEd* Undoubtedly HGT is integral to higher life forms… but we know almost nothing about it, bro.

    [CZ: These are two of many studies documenting horizontal gene transfer. To include a link to every paper would be absurd. I chose these two papers span the history of life. Prokaryotes dominated the planet for the first couple billion years of evolution. The butterflies are one example of gene flow between species in animals, occurring in the recent past. Far from a preliminary hunch, this study is based on the study of entire genomes, building on years of previous research on the insects. If you’re confused, I suggest you start reading some research, bro.]

  3. Funny, just before coming here I was reading about this plant that stole a bunch of genes: http://schaechter.asmblog.org/schaechter/2013/09/who-would-have-thought-biggest-flower-biggest-gene-thief.html

    But I was amazed to find this wasn’t generating the same drama as other GMO projects are. And I’m curious about why that is. Have activists just not yet figured out how to blame it on the Big-M? Don’t have their marching orders from Mike Adams yet? Mercola hasn’t got a detox potion for them yet?

    Because if your fears are “playing God” and gene flow, these issues would be the same as in crop plants. In fact, I’d be much less worried about crop plants because they need so much human care to thrive.

  4. I’m not sure that specific, directed genetic engineering can be said to be no different than natural or even artificial breeding, or HGT. Lots of different chemicals mix naturally, but do you find TNT in nature? How sure are we that these cases of similar genes in different animals are due to HGT and not some other phenomenon, such as parallel evolution, if we haven’t observed the mechanism(s) of transfer? Remember, a lot of genetic material that was once considered undoubtedly the leftover junk of ancient inheritance has now been found to be functional, because it did something other than what we thought genetic coding always did.
    Then, too, we might wonder, how much genetic engineering (or for that matter, cross-breeding) can we do before saving a species becomes creating a new species? And is saving some species by human actions the best thing for the entire biome as it changes? Lots to think about here, lots of potential for surprises of all sorts.
    Then, yet again, maybe the climate is already over the edge and has fallen into a self-sustaining feedback loop that will wipe out most macroscopic life despite anything we can do. Hmmm, maybe the Mayans had it right, it’s just that the beginning of the end was too subtle to observe. 😉 :) 😉

  5. I may be a hopeless “romantic” but where does this genetic intervention stop? Will we live in a world some day soon where all plants and animals (and humans) are genetically modified? I find the prospect of such a world very daunting and hope never to see it. We’ve already intervened way too much on the material world, why don’t we focus instead on protecting it as much as possible and letting it do its own thing?
    It seems to me that man is the cause of this extinction crisis, and instead of owning up to it and trying to fix it in a responsible way, we’re trying to create ways to remedy it that may actually make it worse, continuing in the same human intervention logic and “playing God”.
    You may insert a gene in an animal to render it resistant to a virus, but how do you know that this gene won’t have other consequences, that it won’t, for instance, modify the animal’s behavior in some completely unexpected way and upset the balance of nature even more? I think this kind of experimentation could be very dangerous.

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