[danbruc]

Without knowing anything about the general or scientific use of those terms, just by looking at the words, I think it is fine the way the title is worded.

What is the actor here that responds? It is the process of evolution, in the same way you could say the climate reacts to a change in solar activity. So the process of evolution reacts to a change in the ecological system - more poachers than before - by changing the elephants to no longer having tusks. And the mechanism that achieves this change is that the elephants with the genetic variation making them tusk-less have a higher chance of passing on the genes because they are less likely to be killed by poachers.

[sph]

The issue OP has is that the article conflates cause with effect.

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

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.

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

[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.

[deafpolygon]

Isn't that the very mechanism under which evolution operates? Survival of the 'fittest' doesn't mean strongest/fastest. Clearly, due to poaching activities, tuskless elephants are being 'selected' for survival.

[hoseja]

Survival of the fittest is only an approximation, the true state is a tautology though: survival of those who survive.

[rrgok]

Dumb question: I'm always amused by this phrase "...as if nature is intelligent and driven by some purpose..". Are you not, as human being, part of nature? How is possible from an unintelligent being emerge something intelligent? Either the seed was already there or otherwise I don't know how it would be possible. Would you consider human beings not intelligent and not driven by purpose?

[sph]

I rephrase: evolution of life as we know it (that's what I meant by nature) is not intelligent nor driven by any purpose, not even survival. It's randomly throwing shit at the wall and seeing what sticks. Maybe the resulting organism lives longer, maybe not.

We only see the result of it. The observation that evolution helps find a better local maximum is literally survivorship bias.

[robocat]

Evolution is a severely misunderstood and misused word. We say a business evolved, to mean changed. We say we evolve an idea, with the implication of intelligent action. We say someone can win the Darwin Award even if they are older and already reproduced: to properly win the Darwin Award, one would need to die before reproducing, or kill their genetic offspring as well as themselves (to properly win the Darwin Award, one would need to kill all the genetic branch of their family tree).

Biological evolution is due to reproductive selection. Evolution is primarily related to reproduction: survival only matters if it affects reproduction (after all, nothing survives in the long term).

Evolution is not really defined as random change: evolution occurs due to selection pressures that amplify the genetic population of the most successful reproducers.

Genetic mutation and recombination is somewhat random, but not purely random (certain mutations are more or less likely, and the pool of successful recombinations is very biased).

It is a frustrating topic, because in biology evolution has a very particular meaning, yet biological evolution is usually misunderstood. The misunderstanding is due to the popular incorrect metaphors and alternative meanings for the word.

https://wikipedia.org/wiki/Evolution

Disclaimer: I am not a biologist. I’m trying to be as clear as I can, while making sweeping simplifications (e.g. ignoring kin selection etcetera!) I welcome any mistakes being corrected by lurking biologists.

[deafpolygon]

Evolution of life is different from mutation. We can have mutation anytime, but evolution of life is more or less the basis of 'natural selection' in which mutations that favor survival is selected.

[gumby]

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

You might want to read “The intentional stance” by the famous philosopher Daniel Dennett. This is a pretty useful analytic approach for many problems (e.g. we commonly say things like “the thermostat tries to keep the temperature within three degrees of its set point”).

I agree it is distressing that many people interpret such metaphors literally.

[throwawaymaths]

If we're going to play semantics here, then yes, maybe the first elephant to be born tuskless is the cause but every subsequent tuskless elephant is an effect elephant, so, the statement is still true, if only for an overwhelming majority subset of the elephants.

[hombre_fatal]

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

This has become the midwit anthem, as pg put it, whenever we use causal language to describe evolutionary pressure.

[Konohamaru]

If the poaching activity is acting as an amplifier for that rare mutation's frequency, then yes, the poachers are in fact causing those elephants to evolve not to have tusks.

[chiefalchemist]

It's not that it conflates per se, it's that it gets the text book defintion of evolution completely wrong. Full stop.

You're correct. This happens often, too often.

[spfzero]

I don't know if I would call this an evolutionary response. It's more like the remnant effect of the one-time bottleneck the article mentions. The proportion of females with the gene for tusks was almost wiped out, while the number of females without that gene stayed the same.

There have only been a few generations gone by since then, but you would imagine the same factors that made the gene for tusks more successful in the first place, would start to again predominate, but it will probably take many generations for it to come back to where it was. That part, the recovery, could be called an evolutionary response.

[justsomehnguy]

> change in the ecological system - more poachers than before - by changing the elephants to no longer having tusks

Change in the body - more torn hymen than before - by changing the humans to no longer having hymen.

Right?

[Chris2048]

Not sure why you think this example is better - a torn hymen isn't as fatal to humans as a poacher is to elephants.

[justsomehnguy]

Because if 'evolution reacts' (q) then it would react by removing hymen. Also because women without torn hymen don't pass genes.

Did evolution reacted by removing tusks?

PS if you start to tell me how a hymen could be untorn even in the case of a complete vaginal intercourse I would slap you over TCP/IP.

[Chris2048]

Why would it? Women without torn hymen don't pass genes because they didn't have sex, not because they possessed a hymen. As soon as they have sex, the hymen tears - so it poses no barrier to passing on genes.