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Female African elephants are evolving without tusks due to ivory poaching

512 points| amrrs | 4 years ago |theswaddle.com | reply

298 comments

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[+] jsnell|4 years ago|reply
In case anyone is wondering about the size of the effect, https://www.nationalgeographic.com/animals/article/wildlife-... has the numbers. Before the war, 2-4% of female elephants were tuskless. Now 32% of newly born ones are.

So it's a significant change, but it's not like this property was coming out of nowhere. It started off about as common as humans having green eyes.

[+] drtz|4 years ago|reply
> It started off about as common as humans having green eyes.

Elephant poaching has been around since long before the Mozambique civil war. The number of tuskless elephants may have been at 2-4% prior to the war, but that doesn't mean that lower levels of poaching didn't push it up to that level from some much lower naturally-occurring level.

2-4% seems like a _very high_ rate for a trait that could negatively impact a female's chance of survival AND kills 100% of her male offspring.

[+] csours|4 years ago|reply
Evolution is an umbrella term, but in the most general form, evolution means a change in genetics in a population over time. So yes, the genetic 'option' was there before, but it is advantageous now.
[+] gwerbret|4 years ago|reply
The first figure of the paper they reference [0] has the numbers for this study:

-- 18.5% of females were tuskless before the war

-- 50.9% of females were tuskless after the war

-- 33% of females were tuskless in the first post-war generation

Of the offspring:

-- 8.7% of females born to two-tusked females were two-tusked

-- 44.7% of females born to tuskless females were tuskless

[0]: https://www.science.org/doi/10.1126/science.abe7389#F1

[+] dan_mctree|4 years ago|reply
Is anyone else surprised at how quick species can seem to evolve in these kinds of ways? Asian and African elephants are supposed to have separated millions of years ago, yet still strongly resemble one another. Yet in a few decades, something as fundamental as the presence of their tusks can shift dramatically. And that in a species with very long gaps between generations.

It makes me suspect there's something else going on here that's not just good old natural selection.

Have they done any tracking to confirm the tuskless elephants are actually being born to tuskless mothers? Or could it be that the parents are actually affecting the way their offspring are born in some lamarckian-esque sense? If there'd be some trick animals can pull to change their offspring in some ways, that ought to be highly effective for long term species survival and should thus be highly selected for.

[+] dheera|4 years ago|reply
As sad as this is, how does this kind of evolution happen?

I imagine the poaching process doesn't actually differentiate tusked and tuskless elephants, both types of elephants would fall into the trap and die? And then if it has tusks the poachers take them, if it doesn't have tusks the poachers just abandon the dead elephant?

Or does their trap actually trap them by the tusk?

[+] saghm|4 years ago|reply
Now I'm worried that in a couple hundred years a third of humans will have green eyes because all the blue ones have been harvested by aliens.
[+] sriram_sun|4 years ago|reply
I had a couple of questions:

Are 100% of tusked females giving birth to 32% of the newborns without a tusk?

What % of tuskless females give birth to tusked females?

[+] 8eye|4 years ago|reply
wait what? i didn’t realize my green eyes were rare. interesting and also that’s a huge jump from 2-4%, honestly at least we don’t have to worry about them going extinct, but still sad
[+] baby|4 years ago|reply
Downvoted for weird statements about green eyes. If there is a back story include it in your comment.
[+] mulmen|4 years ago|reply
Is this actually evolution or just selective breeding?

By killing elephants with tusks the poachers are favoring elephants with the no-tusk gene.

This isn't a lot different than killing a dog that bites sheep, which is how we bred herding dogs. Or a wolf that eats your baby, which is how we domesticated dogs.

This trait already existed so it certainly wasn't "engineered due to mass poaching for ivory" as claimed.

[+] TehCorwiz|4 years ago|reply
Evolution IS selective breeding. The members of a species most fit for their environment are successful in procreation. The female elephants without tusks are surviving at higher rates which is resulting in more offspring with no tusks. This causes a shift in the population where a trait previously with no or little benefit becomes advantageous and the shift in genetic makeup of the whole population evolves.
[+] hcarvalhoalves|4 years ago|reply
Humans exerting selective pressure are also part of nature, so I guess this is evolution.

"Selective breeding" is a term used when humans engineer species on purpose. In this case it's the opposite actually, elephants are adapting to survive poachers. Selective breeding would be if poachers started raising tusked elephants in farms.

[+] smk_|4 years ago|reply
Selective breeding is one form of evolution.
[+] caf|4 years ago|reply
The only distinction is really that selective breeding is intentional - which is not the case here.

Was it "selective breeding" when MRSA arose due to our use of antibiotics?

[+] max_|4 years ago|reply
Tuskless elephants probably due to hunting have a better chance of passing their genes.

Which makes it eligible for "Natural Selection"

[+] BuffaloBagel|4 years ago|reply
Cool side story is the American tech millionaire who has dedicated his life and fortune to the recovery of Gorongosa National Park.

https://en.wikipedia.org/wiki/Gregory_C._Carr

https://gorongosa.org/greg-carr/

[+] theaussiestew|4 years ago|reply
That's really inspiring, I'd love to do something similar if/when I'm more financially free. Got any other examples of people doing similar things? We definitely need more people doing this, rather than trying to get to space.
[+] mysterydip|4 years ago|reply
What if unicorns at one point existed, but were hunted for the superstitious power of their horns, leaving only the hornless to reproduce and eventually eliminate the gene? How would we know?
[+] tombert|4 years ago|reply
Honest question from someone who knows virtually nothing about chemistry or material science: is there a difference in quality between synthetic and natural ivory? If not, why is poaching even still a viable market?
[+] tw04|4 years ago|reply
This will probably be downvoted but the reality is it's because there's a ton of new money in China where they're still valuing things like Ivory culturally. There's no cultural stigma at this point. The government has banned it but the black market trade is still strong. See shark fin soup as another example.
[+] estaseuropano|4 years ago|reply
Superstition. Elephants and tigers are not hunted for inherent qualities of their bodies, but for the belief that consumption of their parts in various ways helps health/virility/...
[+] BitwiseFool|4 years ago|reply
Ultimately, a good number of people will want "the real thing", even if it is virtually identical. There are plenty of people who think lab grown diamonds are illegitimate, despite having the exact same chemical composition as mined diamonds. For the rich and powerful, the Ivory is more important as a status symbol than anything else. Synthetic Ivory is effectively useless as a signal.

Plus, there are people out there who sincerely believe that Ivory works as an ingredient in medicine and they will seek it out.

[+] bussierem|4 years ago|reply
Unfortunately (even ignoring chemistry/matsci), one of the answers to that is simply "natural ivory is becoming a scarce resource". When something is scarce, it becomes sought after, which can result in it even becoming a Veblen Good[1] over time.

[1] https://www.investopedia.com/terms/v/veblen-good.asp

[+] eberkund|4 years ago|reply
I imagine people view it similarly to leathers made from animal hides to synthetic materials. Synthetics may be better in some ways but people are in-part attracted by the character or feel that the imperfections of a natural material provide.
[+] abruzzi|4 years ago|reply
as an amateur pianist, I've played pianos with and without ivory keys, and the feel of ivory is a bit better. I'm not sure why, but it seems like it doesn't get as slick from sweat as you play. Of course, piano keys are not the cause of current ivory demand to the best of my knowledge, and I'll happily take non-ivory keys.
[+] pengaru|4 years ago|reply
When you have over a billion people in a culture valuing ivory, it doesn't take a large percentage of holdouts/morons/assholes/psychopaths to pose an existential threat to Elephants.

Multiplication is a bitch.

[+] bogwog|4 years ago|reply
> Researchers found the number of tuskless female elephants in Mozambique increased by almost double over 30 years. This overlaps with a period of civil conflict, where armed forces slaughtered 90% of the elephant population to produce ivory. This ivory went on to finance the conflict.

People suck.

[+] ThinkBeat|4 years ago|reply
A lot of elephants are killed for the ivory in their tusks

Some elephants are born without tusks and live much longer.

Natural mating between tuskless elephants will dramatically increase.

This will result in the trait being propagated rapidly.

[+] PradeetPatel|4 years ago|reply
At the risk of being downvoted to oblivion, is there such thing as ethicially sourced ivory?

If not, I imagine the only reasonable thing to do would be to educate and raise awareness on the catastrophic impact poaching has on the elephant species as a whole.

[+] beebmam|4 years ago|reply
With discussions around evolution, I try to keep in mind that the main pressure for evolution is from natural selection, and natural selection works on death. Plenty of species have been "naturally selected" for total extermination.

It's difficult to keep ethics out of discussions when facing the reality of life: that there is a massive amount of death and suffering, and it's a terrifying thing we're all forced into, including these elephants.

[+] eevilspock|4 years ago|reply
Makes me wonder how human activity is evolving our very own genetic pool. Examples: competition vs cooperation, male vs female height, our immune system.

We have long had a culture where men prefer mates that are shorter than them, and women prefer mates that are taller. This results in constant pressure on the pool resulting in men being on average taller than women. Will this change over time as we outgrow this rather primitive preference? (Sadly, even many feminist women have clung to this preference.) Not all species "prefer" that the male is bigger or stronger than the female.

An obvious one is our reliance on modern medical technology, and drugs in particular. Are our bodies becoming less able to fend off disease?

The most important one for me is the balance between those genes that give us our selfishness and those that give us empathy and love. What impact does an ever more individualistic culture and an economic system that defines selfishness as a virtue have on our gene pool?

[+] Rphad|4 years ago|reply
This reminds me of this study that polled academics and students about the evolutive process that happens. The results are quite decieving. https://journals.openedition.org/ress/2698
[+] SamBam|4 years ago|reply
For those who don't want to read a long French article: the conclusion (as I understood it) is that most people imagine teleological, or goal-driven (the authors describe it as "finalist") reasons for this very change in tusks. That is, even when the subjects consider that poaching may be the cause in the change in tusk allele frequency, they say it's because the elephants "want" not to have tusks, or that evolution is "deliberately" evolving away from tusks in order to protect the elephants.

This is in contrast to the actual explanation, which is simply that if you kill the elephants with the tusks alleles and prevent them from breeding, you'll have fewer of those alleles in the subsequent generations.

I'd say this result is not so "deceiving," as someone who has prepared evolution curriculum in the past, the teleological explanation is extremely seductive, even for educated people.

[+] bambax|4 years ago|reply
Elephants are not "evolving" and it's not a "response" to poaching! Poachers killed elephants with tusks, and as a consequence elephants without tusks have a reproductive advantage.

This is more like dog breeding than about nature fighting back.

[+] mmoskal|4 years ago|reply
Not sure about the linked article, but the paper was also mentioned in last week The Economist, and it said that the number of tusk-less elephants was already dropping (it peaked 50% and now is 33%) due to conservation efforts.
[+] mleonhard|4 years ago|reply
Has anyone tried raising elephants using industrial livestock methods, for harvesting ivory and reducing the price to reduce poaching?

I expect that selective breeding could yield elephants that produce large amounts of ivory continuously. Elephant generation time is a minimum of 11 years (2 years gestation and 9 years for females to reach sexual maturity). The project would take many years.

Other animals produce ivory. Common warthog has a 2-year generation time. Hippo is 7 years. Walrus is 6 years. Narwhal is 7 years.

[+] nyc111|4 years ago|reply
In the Science article they wrote, “Poaching resulted in strong selection that favored tusklessness amid a rapid population decline.” And, “Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium.”

So, there was a change in the genes, but how do they connect this fact with poaching? I don’t see the relation. Surely, elephants themselves, cannot decide to change their genetics as a reaction to poaching.

[+] asdff|4 years ago|reply
It's not like evolution detects this. If you kill off all the blond headed people in town, all the babies next year will be born with brown hair. The tuskless variant was already in the population at some proportion, but due to tusks being a target of poaching, those that carry the tuskless variant are more likely to survive and have offspring, who are also going to have this tuskless variant. Over time, the population will shift and this tuskless variant will be present at a higher proportion in the overall population.
[+] duskwuff|4 years ago|reply
> how do they connect this fact with poaching?

Poachers kill elephants for their tusks. A poacher won't kill an elephant with partially formed or no tusks, as it has no value to them. This allows elephants with the tuskless gene to survive and eventually reproduce where other elephants would not.

[+] drclau|4 years ago|reply
It's artificial* selection. The ones with husks die** more often before having offsprings, or will on average get to have fewer offsprings, in comparison to the tuskless individuals.

*) Humans are putting the pressure.

**) Are killed by poachers.

[+] bussierem|4 years ago|reply
Evolution works thanks to natural pressures -- in this case, a mutation in the gene gives an elephant no tusks, and thanks to this they are not killed by poachers. That elephant is lucky enough to survive to pass on its DNA. The recessive gene, over many generations, grows more dominant as more and more elephants "benefit" from having no tusks by not being hunted.

So the elephants aren't reacting to poaching -- the "reaction" is a random mutation that happens to align with external pressures, causing a shift in genetics for the population.

[+] aaaaaaaaaaab|4 years ago|reply
Random mutations happen all the time. If there’s selection pressure that favors a given mutation, it will proliferate.
[+] geoffmanning|4 years ago|reply
Surely? I wouldn't discount the power of intention when applied to the all too common occurrence of deep emotional stress of experiencing the loss of your family in such a violent display.
[+] Markoff|4 years ago|reply
I would like to see numbrs for elephant population, considering this study takes into consideration 30 years of heavy poaching and average life of african elephant is at least 60-70 years, couldn't this be just smaller sample group? so obviously if you kill 90% of elephants and leave only 10%, most of them tuskless, their offsprings will be much more commonly tuskless, though it doesn't mean it won't return back by itself over time
[+] chiefalchemist|4 years ago|reply
> Published in Science on Thursday, the study looked at the genetic changes engineered due to mass poaching for ivory.

This interpretation of evolution is a myth that needs to be busted. Nothing is being "engineered". What is happening is simply: no tusks is an advantage. That is, no tusks means less likely to be hunted / killed.

As a result, the tusk genes in the gene pool are less available. The no-tusks genes more.

In short, and ultra-simplified, evolution is reactive.

[+] anonu|4 years ago|reply
Is this how evolution works? The article implies a cause and effect. But i always thought genetic variation was random and if that variation conferred some advantage in the world, it would dominate over many 1000s of years.

Also, i imagine elephants have long gestation periods and live longer than say your average single cell organism. Meaning the "evolution cycle" if you will, is much more drawn out..

[+] cabalamat|4 years ago|reply
> Relentless ivory hunting over decades has caused elephants to evolve in a way we never imagined them to.

This is only true if "we" have very little imagination.