While sad as a whole, the responsiveness of evolution is beautiful in this case.
It also demonstrates that human efforts to stop poaching have not been successful (otherwise this evolution wouldn’t happen), but luckily, nature responds.
It also demonstrates that human efforts to stop poaching have not been successful (otherwise this evolution wouldn’t happen), but luckily, nature responds.
If only humans were harvested for bony growths?
Incredible, good
Not mutually exclusive
I believe natural selection includes the influence of any species related to the species in question as predator or prey, and humans in this case are predators. We may historically be responsible for far more processes of natural selection than we're aware of!
You're right that it's exceedingly rare to see us so directly play a role in natural selection today (as opposed to indirectly through affecting the environment), which makes this very interesting.
If it weren’t for us hunting these elephants for their tusks, there isn’t a reason they’d evolve in this manner. So I just wouldn’t call that evolution by natural selection. Same thing if we set off to exterminate all mosquitoes.
But I do get your point. I’m conflicted if we can count ourselves as any other predator species when discussing evolution.
The way I understand this there was likely a very small population of elephants already without tusks, maybe some kind of genetic defect that happened to be an advantage once you add greedy people into the mix. Or what else is possible is that there was one off mutation that produced small family of elephants that poachers wouldn't touch and these spread over decades.
Think about this, if today Covid mutated to kill almost all people but spared 0.1% with a certain gene, you would suddenly observe entire human population becoming immune to Covid.
This does not necessarily mean any new genetic material or "nature responding". Maybe nobody noticed the gene and it suddenly became very visible and comprising large part of population (while it declined dramatically as elephant population did). We may have missed elephants without tusks because they were just freak of nature but now they become proliferating because it becomes an advantage.
EDIT:
Selective pressure is part of evolution process, but it is not enough for evolution.
Evolution requires both mutation AND selection.
So, if the mutation was present BEFORE poachers happened, you can't really say that Mother Nature RESPONDED to poaching by evolving new mechanism. The word "response" implies causal relationship between poachers and mutation+selection of better equipped elephants. But if the mutation has already been present then there is no causal relationship and this wasn't a new mechanism.
But this is exactly how evolution works. There are always mutations in every generation, and sometimes those mutations are beneficial. These genes are being selected by the organism's environment, and if the environment changes, then the genes that are selected will be different. That is "nature responding". Elephants without tusks (or very small ones) are more likely to survive and produce offspring.
Genetic Drift is always occurring randomly. Some elephants had a "genetic defect" to live without tusks before poaching. Some humans had the 0.1% resistance to the hypothetical super-covid before the disease.
As new environmental conditions emerge (human poaching, hypothetical super-covid, etc), some genes are far better adapted to the new environment (tuskless, covid resistance, etc). Those genes then thrive in the new environment and consume the available resources left by those killed off.
That's not how evolution works. Evolution doesn't ever involve a "feat of nature suddenly evolving defense mechanisms".
I don't understand this comment, unless it's a way to say the above, that evolution does not involve sudden spontaneous changes in response to an external stimuli.
On a related note, if "ability to evolve" is a characteristic that can be selected for that would explain why all complex life uses sexual reproduction. Mixing genes offers such advantages that most everything that can't do it is still basically bacteria.
I wouldn't get too attached to that idea... in a lot of cases, having one gene responsible for producing a phenotype can be a very bad thing, like oncogenes (responsible for the growth of cancers) and a bunch that determine development and/or aging.
> On a related note, if "ability to evolve" is a characteristic that can be selected for that would explain why all complex life uses sexual reproduction. Mixing genes offers such advantages that most everything that can't do it is still basically bacteria.
Again, sometimes. There are lizards and bugs that clone themselves (parthanogenesis) which can be really handy for when the population isn't doing so hot.
From the article, it sounds like this may have protected them from human predation, but there may be significant long-term negative impacts on the species due to the lack of viable male offspring.
Survive more easily for a couple generations, but go extinct as an all-female species after a couple more...
https://www.science.org/doi/10.1126/science.abe7389
> Survey data revealed tusk-inheritance patterns consistent with an X chromosome–linked dominant, male-lethal trait. 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. One of these loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome in humans that diminishes the growth of maxillary lateral incisors (homologous to elephant tusks).
Why haven't mothers that only give birth to girls taken over the world? Do unpaired girls really die that quickly?
There is big imbalance problem for humans as well, many cultures prefer male children over females, the two largest countries - India and China have big imbalance for different reasons there is estimated 100 million less girls than boys in these two countries alone as result of sex selection/ infanticide etc .