>Most intra-species fighting is not designed to end in murder
That depends a lot on scarcity. If you are a male and you only get one chance at mating, you will probably fight to the death. If you will get plenty of other chances, then you might accept the results of a ritualised non-lethal combat (e.g. giraffes headbutting each other, rather than kicking). Its just evolution + game theory.
Is this backed by some anthropological real world examples, or are you just extrapolating theories?
I read it in an article that was talking about the application of game theory to biology/evolution and I believe it is well supported by evidence. But I can't remember the source.
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What animal species often offers males only one chance of mating ?!
It's common among animal species for males to fight over females, but it's highly uncommon for them to fight to the death, because that is not evolutionary adaptive - it risks the individual as well as the genetic diversity of the group/species (and evolution is selecting for survival of the species, not the individual).
> evolution is selecting for survival of the species, not the individual
This is very wrong. Evolution is selecting for the total reproductive fitness of genes, and to a slightly lesser extent, individuals. There’s no mechanism that helps the process of evolution select for the survival or reproduction of the species. See any recent textbook on evolutionary biology, or read Dawkins, or even Darwin. I don’t know where you got this idea but it’s exactly wrong.
> There’s no mechanism that helps the process of evolution select for the survival or reproduction of the species
The "mechanism" is just the process of evolution itself, and how it plays out in practice, e.g. via punctuated equilibrium.
Over shorter timespans the gene pool of a breeding population incrementally drifts according to the success of individual genetics, but then once in a while, over multiple generations, something in the environment (disease, food, competition, etc) may change quickly and the gene pool as a whole, not just that of individuals, is thereby tested, with accumulations of previously benign changes sometimes suddenly becoming critical. In this way evolution is acting on the entire gene pool - of the species or more correctly of that interbreeding sub-population.
Success in evolution, the ability of the species as a whole to adapt and compete, also requires genetic diversity, not only to avoid inbreeding, but also to provide species level resilience, and species level ability to quickly adapt. e.g. It seems that the success of sexual reproduction is because it is a way to "game the game" by increasing genetic diversity and therefore improve along these axis of resilience and fast adaptation.
There are also social species, such as ourselves, where the social group becomes port of the individuals environment, and genetics best-fitted-to-the-environment becomes a group dynamic.
Nothing about evolution feels sensible or right: and the vast majority of people have severe misunderstandings about how it works (for example the Darwin awards are highly misleading). Even science reporting is often highly misleading[0]. Intuition is not trustworthy for this topic, and neither is our ambient knowledge.
Referencing the Wikipedia article on kuru which references this paper: https://researchonline.lshtm.ac.uk/id/eprint/4514/1/nejmoa08...The suggested evolution is:
* there is one ancestor with a gene that protects against kuru.
* children and mothers without that ancestor often die from kuru
* children of that ancestor have a much higher chance of survival
* eventually everyone is a child of that ancestor
* any children of that ancestor that didn't get the protective gene also eventually die out
The gene is selected for. There are no population effects.
The key part in the paper is where they mention adult men with the gene, because they are measuring the counterfactual of the many males that died because they didn't have that gene (males that ate brains as young kids but then died because they didn't have the gene from that ancestor).
The paper is hard to understand in part because of the confounding effects of males not eating the brains. Plus the confounder of stopping cannibalism in 1960.
The idea of "Group selection" is fundamentally wrong - regardless of how sensible the belief feels. Anybody using the words "group selection" is indicating their belief system, and they usually then have biased narratives to 'support' their belief.
[0] horrifically incorrect sciencedaily link in Wikipedia.
[1] We don't fucking evolve genetic mutations
Fundamentally evolution is selecting for genes, not individuals, and there is no 1:1 relationship between genes and individuals.
Let's say that everyone has a skin color gene that makes them either red or blue. And a new predator turns up that only eats blue things. To you this is a tale about individuals, while it seems that an equally valid, and frankly preferable, view is this this isn't about individuals - it's about being red or blue and is a species level effect.
I suspect the underlying issue is that we are all terrible at unthreading cause from effect.
Words matter. Talking about "species level" is misleading because talking about an effect (blue phenotype) distracts us from the cause (a gene for blue).
And evolution is confusingly another step removed: the red survives because the blue did not.
Most of us struggle to see the counterfactual absence of a something.
The blue "species" never exists - our brains want to find groups and patterns. Our words mislead us.
The same thing is alluded to in the paper: the deaths of people without the gene is what is driving the gene to spread (through reproductive success of those that didn't die).
Reproduction is what matters (which death or sickness may interfere with).
Even the paper is confusing because it talks about 50 year old women (measuring survival bias; not whether they are expected to pass on genes at 50).
(reedits for clarity).
Also read this comment by a real biologist:
https://news.ycombinator.com/item?id=49734849
Have you studied evolution, or is this your own theory?
If individuals share some genetics, and evolutionary selection pressures act on genetics, then it follows, right ?
Not even close. Evolutionary selection pressures don't usually act directly on genetics. Perhaps you are incorrectly attempting to rely on intuition, and over-simplistic phrases like selection pressures. Intuition is incredibly misleading with evolution.
Your pink and blue example is actually a great model to work from. Think about the genes and the expression of those genes, and then think about what is being selected if all the blue animals are eaten.
Or think about what would happen if there was a mountain range, and pink animals were eaten on one side and blue ones were eaten on the other side.
Or think about what if one of the blue fathers has pink polka dots that gave it a 10% better chance of survival.
Always concentrate on watching that genes are passed on by reproduction - getting eaten doesn't have to be a problem if reproduction has already occurred (unless parental investment is needed or you get complicated like kin selection).
I am not a biologist. But 'The Selfish Gene' is one of my favourite books because of the concepts within. Unfortunately I think Dawkins went off the deep end later (with what I thought was religious zeal). The Extended Phenotype is even harder to read, but also worthwhile.
It is a fun topic because many phrases about evolution seem misleadingly about death rather than reproduction. And the meaning of the word evolution is absolutely twisted in everyday conversation. Ignoring the troubles with bible bashers. https://en.wikipedia.org/wiki/Survival_of_the_fittest - "fittest" has an unobvious meaning.
I don't think so. But it isn't my area of expertise.
>evolution is selecting for survival of the species, not the individual
I believe that is wrong. Selection works on the level of the individual and their genes. Dawkins covered this extensively in at least one of his books. Any professional biologists care to comment?
Selection works on the level of the genes. Dying without procreating can still be advantageous if doing so means that enough of your relatives survive, for example. https://en.wikipedia.org/wiki/Kin_selection
I think it's most accurate to say that selection works at the level of genes (or combinations of genes), not of individuals, and of course many individuals of a species will share some/most of their genetics.
You can tell it as a story (easier to teach) of individual success in surviving and having children, which isn't wrong, but it's also not the big picture.
obligate male death happens, but usually in things like spiders after mating, so there's a few examples for you
Fighting to the death and mating are not the same!
There are a number of species where the female eats the male after mating - examples such as praying mantis and octopus. Both octopus males and females die after mating, the female after having protected the eggs, so it makes sense that she sometimes eats the male too (who is going to die anyway). But, examples like this are relatively rare, and for species specific reasons.
"What animal species often offers males only one chance of mating ?!"
"Fighting to the death and mating are not the same!"
Your original question and your current statement are in confliction. Pick one.
> If you are a male and you only get one chance at mating, you will probably fight to the death
This is the comment I was responding to.
The question was about pre-mating death matches between males, not post-mating snacking behavior of females.