There is a tendency to call something an evolutionary puzzle if some behavior is not optimal, and so elaborate, and often quite clever, possible explanations for why it's secretly optimal are devised.
But it's a mistake to think that non-optimal phenotypes require special explanations, when the obvious one is at hand: the optimal solution hasn't been found yet. In this case, the mechanisms that ensure that young are cared for are simply being triggered or activated by situations it wasn't "designed for", and nothing has evolved to prevent that from happening because it's an infrequent occurrence in the first place (and perhaps because any solution to it would be more expensive that it's worth?).
Life works with what its got, and natural selection (and other forms of selection) are not explanations, they're frameworks, models of a type of process. Actual explanations involve actual causal chains with actual stuff in the world.
Yep. Evolution is really just a description of the consequences of differential reproduction. Rare behaviors (adoption) that are not optimal but which are driven by drives (better motherhood) that may have big evolutionary upsides may simply not be selected against very effectively, and evolution is always limited by the pool of mutations and what is possible for the organism at that point. If there is no mutation that both eliminates adoption and preserves the beneficial effects of the drive, it may not happen...
This is not necessarily suboptimal behavior; given that any genetically determined behavior will constitute a categorical imperative among those individuals carrying the genes, and whose offspring gets orphaned is to some extent random, the benefit of having their own offspring cared for in the event of their untimely death may outweigh the cost of raising offspring with whom they have less genetic material in common.
I think people sometimes treat natural selection as making cold cost/benefit kin-selection decisions on a case by case basis and mind controlling the creatures to make those choices. I am straw manning, but my point is it doesn't work that way. It develops predispositions and behaviours. How those predispositions and behaviours play out is the choice of the individual creature (including the case when the creature is human).
Can't you take 'predisposition' to be a little more hardline, and that it removes all 'choice'. We are so 'predisposed' by biology/chemistry that animals, and humans, don't have any agency of choice, no free will to calculate anything.
It appears that occasionally straying from the hard rules provides an overall better fitness to the organism given that the fitness landscape (or fitness seascape) changes with time
To use a computing metaphor, every animal has "buildtime" predispositions and "runtime" choice-making ability. That "runtime" decision making is based on exercising free will, but of course free will is a biologically built-in capability which executes on the deterministic "VM" that is our physical universe.
i.e., we have free will from the perspective of ourselves, but if you zoom out, that free will is just another predetermined physical phenomena.
I think the issue is 'could any other decision be made'.
In the computer analogy, if the 'run time' always arrives at the same answer, because that is the answer from the calculation. Then was there ever a choice?
I guess this and the other comments are really saying just because we have the illusion of free will from our perspective, just assume a choice is being made and roll with it. Don't get tied in knots about the question of free-will, we know we don't have it, but just assume we do in order to make our perspective work out.
> I think the issue is 'could any other decision be made'.
IMO, no.
> In the computer analogy, if the 'run time' always arrives at the same answer, because that is the answer from the calculation. Then was there ever a choice?
To me, there was a choice, but that choice was made by an entity which operates deterministically.
> I guess this and the other comments are really saying just because we have the illusion of free will from our perspective,
Kinda. I would only disgaree with the "illusion" thing. It's not an illusion: from our perspective we DO have free will, we ARE in control. Like everything else, free will is relative.
Realize that when we say "we", each of "us" is a facet of that deterministic universe. The universe is not some big external VM that controls us like zombies. It is us. We are the hardware, firmware, and software of the universe, operating and evolving with agency, modifying one another and the world around us. We're not sandboxed processes. You and I, we are two manifestations of conscious thought occurring in the same grand unfolding of physical phenomena. We see a clear boundary between ourselves and the universe, but that's a human point of view, not a physical truth. When the universe decides something, we decide something, and vice versa.
Maybe that's too far into woo woo land for your taste, but it's how I personally reconcile free will and determinism and it's resolved a lot of the existential dread I used to feel around this. ymmv
Not too woo woo. Hard not to get woo woo on this subject.
It's just that you frequently use the word 'deterministic'. -> "facet of that deterministic universe."
And then also talk about how we have agency.
Not sure how to square those both occurring unless you are just saying at different scales.
Like the universe is deterministic, but on our human scale we appear to have a choice. But that is just appearance because at our scale there are so many chaotic interactions that the world really appears random and we are making choices.
What I'm saying is that in the brain, you keep boiling down the science at each scale, and at some point you don't find any 'agent', each layer is explained, and every action is the effect of a previous cause.
For these purposes, I’m not really interested in the whole question of free will. If you want to take a mechanistic approach, you just need to appreciate that the decisions aren’t being made by “natural selection” but agents influenced by “natural selection”. The ideal agent may be also be quite different from what some imagine. Whether or the agent has “free will” doesn’t affect what I’m saying.
Complicated explanations for what is probably quite simple: The genes are sequences of DNA which have only very indirect and complicated, non-linear effects on the outcome. In this case the genes code for "I must care for my offspring". On very rare occasions this doesn't quite work advantageously (in a strict evolutionary sense), but mostly it does. There may be no practical set of mutations that could fine-tune this behaviour (such as: dozens of changes would be required, but the outcome is negative unless all happen together), so it continues this way.
A genetic lineage may both lose resources to adopting and gain them from being adopted at different times — and where that nets out over 1000+ generations isn’t immediately clear. Survival benefits from having more members at the cost of some resources now is even less clear.
This may be a case of a benefit being selected for on a multi-generational scale; or it could be as you say and a disadvantage.
My argument isn't about if it's advantageous or not. It's that the mechanism (DNA, a long string) may not be well-suited to expressing and adjusting very complex emergent behaviours in the phenotype. There may either not be a way at all to express "show strong maternal instincts but reject all non-related children and surrogate children like pets", or there are too many steps to get there and natural selection would never find it in any reasonable evolutionary timescale.
> My argument isn't about if it's advantageous or not.
I don't know if you're being fair to yourself. It's probably advantageous to have simple heuristics for determining if you should care for something, if that something will turn out to be your offspring 98% of the time. What possible pressure would there be to push that to 100%?
It would be possible for DNA to do better with some sort of signalling. Select for kids that inherit a smell, for example. But to develop that you'd have to start with a bunch of false negatives, and a bunch of deceptive smells would develop to start giving you false positives again.
Nobody is actually doing the calculations, the decisions are arrived at from what evolution has built into us, hard wired based on what has worked in order to get us here.
"Already I can see the chain reaction: the chemical precursors that signal the onset of an emotion, designed specifically to overwhelm logic and reason. An emotion that is already blinding you to the simple and obvious truth"
If a sufficiently large part of a population behaves altruistically, it does makes sense for adoption to happen.
In the example with the elephant seals, if a mother becomes separated from her calf during a storm, having a predisposition in the population to adopting someone else's calf is beneficial to the mother, as her offspring might be adopted as well
Natural selection is not about the phenotype. It is not beneficial to the mother to have "her genes" propagate. Natural selection works on a gene-by-gene basis and, if anything, the genes "use" the individual as a carrier serving their "benefit", not the other way around. Even more precisely, it's about genes becoming more or less widespread in the population. A gene doesn't "care" what happens to one of its carriers. You gain nothing by spreading "your" genes; your genes, however, may use you as a vehicle to spread themselves.
The question is, then, if there is some gene that encourages adoption, will such a gene spread in the population or not? I'm not sure I see why it would. However, if such a trait is already spread in the population, especially if it's not a specific gene but an outcome of others, indeed I don't think there would be selective pressure working against it for the reason you mentioned.
>You gain nothing by spreading "your" genes; your genes, however, may use you as a vehicle to spread themselves.
Getting philosophical here, but what does it even mean for me to "gain something", given that my entire existence is a conglomeration of mostly-cooperating genes trying to spread themselves, and my values, desires, and outlook on life are heavily controlled by said genes? Spreading my genes is the intrinsic value, from which all my other instrumental values like eating tasty food, making good friends, enjoying sex etc are derived.
That's not the way natural selection works. A gene either spreads in the population or not, and individuals are merely carriers of a particular gene. It is no more "your" gene than it is "your" flu virus that you spread when infected. The gene and the virus "use" you; you don't use them.
Of course, because genes, like a flu virus, use us as carriers, they can only spread if we help them spread, so if we come to think of genes that we and others carry as "our" genes then that helps those gene spread. But natural selection doesn't care about gene carriers beyond their role as carriers any more than a flu virus does.
We seem to be agreeing, but I don't think you really engaged with my point with this reply. What is "me"? There is no "I", that exists independently of the genes that "I" carry, that can be "benefited" at the expense of those genes. My genes do not use me. I do not use my genes. I am my genes. It is fundamentally impossible for me to act in a way that is not calculated to spread the genes that constitute me. Any behavior that I perform is the result of inclinations which have been programmed into me for the express purpose of successful reproduction. No other selection pressure exists.
(To avoid an argument: the picture is murkier when one considers that we are also meme carriers, which also affects our behavior, and that memetic and genetic reproduction are not entirely aligned; nevertheless, we have no more control over our memes than over our genes, so the core point remains: there is no "me").
> There is no "I", that exists independently of the genes that "I" carry, that can be "benefited" at the expense of those genes
I disagree, because even if you were indeed merely the sum of your genes, natural selection works on a gene-by-gene basis, not on a full genotype basis. Furthermore, each of "your" genes -- unlike your genotype -- is not unique to you (that's the whole point of genes spreading; a successful gene is one that is carried by many individuals). Unless you clone yourself, spreading your genotype is simply not an option available to you whether you see value in that or not.
In other words, even if you believe you are no more than the sum of the words that constitute the sentence that is your genotype, natural selection does not work to spread that sentence but its constituent words. In fact, it works to spread only some of those words and against the spread of others. In a way, the genes you carry are in competition with each other.
> It is fundamentally impossible for me to act in a way that is not calculated to spread the genes that constitute me. Any behavior that I perform is the result of inclinations which have been programmed into me for the express purpose of successful reproduction. No other selection pressure exists.
That takes things way too far. We are not "programmed" by our genes, as seen in identical twins. But to whatever limited extent genes do "program" us, their spread is not necessarily dependent on you reproducing. That's the whole discovery of kin selection: because your genes are shared with others, behaviour that sacrifices you for the sake of someone else will also spread your shared genes in the population -- just not through you.
It is though, at the group level. The groups that adopt will have better survival than groups that don't, if the environment is such that parents regularly die while the cubs are small.
Do you think group selection applies to eusocial species such as bees? It must. If so, imagine a species that is incrementally less social than eusocial. Unless there is some threshold degree of sociality required for group selection, then there clearly some level of group selection occurs for other animals (whether or not it's a major effect)
I've often pondered why some animals make friends.
I grew up on a small farm, where we mainly kept sheep. Most of the year the ram would have next to no interest in the yews (female sheep), unless there was some sort of threat - he'd just be off doing his own thing.
Once my mum bought a calf as auction as it was so cheap (from memory 20p - most cows are sold in lots of 6, but this was an odd lot and no-one bid) - the calf loved us and wanted to be with us whenever we were in the field (and to be bottle fed), but the rest of the time would hang out with the ram.
That September a family brought a pet duck to us as their daughter couldn't take it to university and the parents didn't want to look after it. We said sure, and as soon as they left we put it in the pond. The geese we had started to attack it, and the duck ran out of the pond and hid between the legs of the cow who just happened to be near.
And that was it - for the rest of the year the duck, cow and ram were always together - they'd pace up and down the field together and at night the duck would either sleep between the cows legs, or curled up to it, if the cow was seated/lying down.
They genuinely seemed to all get a lot from the bond they shared as three 'others'. Sadly a couple of years later, after a few of our chickens were eaten by a fox, my mum tried to put the duck away each night. As she was trying to catch it the cow started stamping to tell her to leave the duck alone, and accidentally stamped on the duck, breaking its leg. We took it to a city farm and 'gifted' it to them - but I am told it made friends with their ducks, though I didn't recognise it when we visited - but I was only about 8 at the time.
As the article says, animals are not automatons, despite our tendency to see them as so. Maybe they do it for similar reasons why we adopt pets? Biologically, it doesn't make sense to keep a modified wolf in my house competing for my resources either.
Exactly. Us humans do a lot of things that aren’t optimal but make us feel good for some reason. Why do people like cats? They often are assholes but we still love them. Why would animals be different?
You can feed and care for an extra mouth and still procreate. Animals tend not to have such luxury, some will abandon the weak offspring because of that.
Not sure what the point of the article is. Caring for young is a strong behavioural program, and errors happen, seems to be the summary, not too enlightening. They could have mentioned cuckoos, which actively exploit these errors.
Or maybe the author has read too much into it! Maybe it's just a drift of the instinct animals have for their offspring, an association error of the animal's brain. Not unlike the mistake they make when they eat (and sadly die) from plastic litters.
The question "why" has several "layers", if you will. A drift off instinct can be more than "just" something. Many of our own behaviours must have some roots in such drifts, yet are more commonly discussed in terms of culture etc.
I think a tendency toward animal husbandry, either genetic or cultural, is just clearly an evolutionary benefit. We domesticated all the various things we keep as pets and livestock for what were good reasons in the ancestral environment, even if those reasons don't persist for most people today.
One theory is it requires multiple phases. First an unintenional egg mixup. First there are eggs laid by one bird, then it's abandoned for some reason and another bird of a different species lays eggs on top. All the chicks are raised by the parents as if of the species of the latter bird, but one or more of the hatchlings are actually from the first batch, a different species. The chicks will absorb enough of the habits as to mate with their "social species" instead of their "biological species". (Am not a biologist and don't know the precise terms).
I'm curious whether the whole tree of life being related plays some part in cross-species adoption (and even animal behaviour in general???).
In the sense that genes don't 'want' anything, but selection creates a pressure towards overall adaptation and survival... a lion shares a lot of genes with a leopard. Is it pro-genetic-survival in some very broad sense for a lioness to care for a baby leopard? I guess not, if adults of those species compete to the death... but many species don't seem to do a lot of murdering, beyond predation for food. Animals sometimes seem quite incurious about other activity close to them, except when they need to eat. Could there be some small selection pressure towards live-and-let-other-DNA-live?
If you want to explain a particular type of animal behaviour you should probably familiarize yourself with Tinbergen's Four Questions: https://www.youtube.com/watch?v=8NRU6iH5lzs
It is just a bug in the system, the parental instinct misfires. Similar to the cases where parentd abandon their offspring for, what to us look like, superficial reasons.
Could it be that animals, like humans, aren't just sacks of chemicals? Could it be they're not computer programs, but that they are, in fact, animals?
This is why I despise practically every discussion of "why" when it comes to talking about observed traits and evolution like this. People invent this bizarre deterministic model of life as it it were purely chemical or computational and could be controlled & understood as such. As if every single little trait has design intent.
You have one guy in this thread that's like, "Would this imply that humans’ propensity to keep pets is also an association error in the brain?". Like holy shit dude, I don't know, but maybe people just like pets. Maybe pets like pets. Maybe pets like us. Maybe we aren't computer programs whose nature is defined by scripts and wiring. "Association error". The fuck? We're not computer programs. We don't have "errors".
Like what a dull and inhuman lens to view the world with: "We're all just computers", or "We're all just a bunch of chemicals". I wonder, do you also think of me as a computer or a chemical sack? Do you view my child that way? My cat? If you do, that disturbs me, because then you may be tempted to treat us as such, when we're all so much more than that.
Because evolution made sex feel good, and caring for kids feel good, and the two together lead to positive evolutional outcomes. It never specifically made "caring for your kids" good.
But it's a mistake to think that non-optimal phenotypes require special explanations, when the obvious one is at hand: the optimal solution hasn't been found yet. In this case, the mechanisms that ensure that young are cared for are simply being triggered or activated by situations it wasn't "designed for", and nothing has evolved to prevent that from happening because it's an infrequent occurrence in the first place (and perhaps because any solution to it would be more expensive that it's worth?).
Life works with what its got, and natural selection (and other forms of selection) are not explanations, they're frameworks, models of a type of process. Actual explanations involve actual causal chains with actual stuff in the world.