[danbruc]

It's not poachers that cause elephants to evolve not to have tusks.

Cause and effect are very complex concepts, probably not even well understood ones, but I would rather avoid descending into the philosophy of cause and effect, so I will just pick a potentially naive idea of cause and effect. Assume a counterfactual world without poachers, would the elephants evolve to be tusk-less? No, so the poachers cause elephants to become tusk-less.

It's that some elephant got a rare mutation, and those mutated elephants aren't as targeted by poachers, thus are able to survive more easily.

That is the mechanism at play under the hood, but it does not mean that the abstraction of poachers causing tusk-less elephants or even more abstractly that evolution causes tusk-less elephants under those circumstances are not also valid descriptions.

Plenty of popsci journos write as if nature is intelligent and driven by some purpose.

Which - to a certain extend - is fine. Countries go to war, wars cause destruction, companies go bankrupt, rivers flow to the ocean, holidays make people happy, programs produce outputs, moving the mouse with the left button down selects text, ... none of this is really true in a certain sense. But that is fine, all our words are abstractions and we understand what they really mean, they do not have to be understood literally and the meaning can be context-dependent.

[bigDinosaur]

It's amusing how downright hard it is to avoid teleological explanations of evolution. In this case it is important to note that this mutation presumably existed before poachers so they cannot be the cause of the actual genetics of tuskless elephants - but they are the cause of why the ratio is now changing. So I'd say your counterfactual is wrong: there would be a few tuskless elephants but having no evolutionary advantage they would not become the dominant phenotype.

If a species lacks the preexisting genetic diversity here, it dies.

[phkahler]

>> In this case it is important to note that this mutation presumably existed before poachers so they cannot be the cause of the actual genetics of tuskless elephants

This sounds like an argument made by creationists to deny evolution. The genes were always there and we are just seeing a change in expression.

When people of science have silly public debates like this, science loses. Stop being pedantic!

[haswell]

Creationists will always find things to attach to their arguments. A discussion on HN will not change that.

As a community, HN tends to be a place where such discussion is encouraged and relished.

“Pedantry” here (I’m not convinced it’s pedantry) does not make “science lose”.

If anything, I appreciate the tendency to discuss the more intricate aspects of things. In a world that trends ever more towards oversimplification and binary thought, it’s encouraging to find folks willing to debate the details.

And details often matter.

[bigDinosaur]

When it comes to random mutations what other explanation would you use? I genuinely don't see how that sounds like an argument made by creationists. A creationist will simply state that genes never evolved or that they've only had six thousand years to evolve. Yes, obviously something caused these mutations but it wasn't the poachers, the original selection effect before the poachers here was that the mutation didn't cause a decrease in fitness otherwise (which it does, as it kills males before birth).

[phkahler]

Creationist have argued that genes don't change, but can turn on and off to create variations. Some of them use this to claim actual observed cases of evolution are not improved species, just using what was already there. Of course that argument falls down in cases where the before and after genome is sequenced and shows new changes, but they will still make the argument.

[hoseja]

How did you get change in expression out of that? It's a change in population.

If some killerbots started killing everyone above 4 feet tall, would you see the sudden prevalence and thriving of people with dwarfism to be an argument for creationism?

[danbruc]

That is the way I wanted my sentence to be understood, »evolve« in »[...] would the elephants evolve to be tusk-less?« is intended to mean nothing more than become dominant due to evolution and I do not see how that word in that context could be understood as anything else.

[bigDinosaur]

Fair enough. I don't actually think you're wrong, to be clear, I think it's just easy to mix together related but distinct concepts here and the teleological angle makes that surprisingly easy to do (but it's almost impossible to actually avoid).

[danbruc]

Isn't teleology a red herring here? We may use language that sound teleologically - nature wants this or that - but that does not imply that we actually have any teleologically world view behind that. If someone says that the universe wants to minimize the action, then I don't think they ascribe any desires to the universe [1], they just want to say that physical systems behave in a way that minimizes the action which we figured out by inspection and experiment.

[1] At least by default, they can of course clarify that they actually think the universe has desires.

[sph]

> Assume a counterfactual world without poachers, would the elephants evolve to be tusk-less?

Of course they would! I can't see how you can disprove that. In both that world and ours there are or have been tusk-less elephants, elephants with two heads, elephants that live 150 years.

Evolution is pseudo-random. The whole of nature gives context and some variants thrive better within this context. It is illogical to take life out of its natural context and think whether it would have evolved differently.

Your question should be rephrased as "would elephants without tusk thrive and outcompete regular elephants in a poacher-less world?" Maybe yes, maybe no, but my point is that evolution occurs every time a new elephant is conceived, and maybe the resulting animal lives longer.

[danbruc]

[...] would the elephants evolve to be tusk-less?

The word »evolve« in that sentence means exactly what you say, »thrive and outcompete regular elephants«, or at least that is the way I wanted it to be understood. What is your definition of that word in that context that makes the sentence mean something different?

[latexr]

> evolution occurs every time a new elephant is conceived

Mutation occurs. Evolution is when the population changes, not individuals.

In this time frame it is unlikely elephants would have evolved without tusks in a world without poachers, because in that scenario tusks are an advantage.

[johannes1234321]

> maybe the resulting animal lives longer.

Living longer is secondary to evolution. Producing more offspring, which can produce offspring itself is what matters.

If an animal becomes old and endangers the herd it is harm for selection. If it can't produce offspring anymore, but protects the youngers it can be useful for survival rate.