I have often heard it pronounced (Including by Eliezer) that group selection is not a thing, that evolution never selects for “the good of the species”—and it is true, in the sense, that if evolution is given the chance to throw the species under the bus for a slight gain to the individual, then it will never hesitate to do so.
But there is a sense in which a group can be selected for—assume feature A is always bad for whichever species has it, and there are two species which occupy overlapping niches—one group with feature B, which makes feature A unprofitable for the individual, and one group with feature C, which makes feature A profitable for the individual. Assume features B and C are sufficiently complex that it remains constant within the group (there are many such biological traits—human eyes, for example, tend to be much more similar to eachother than to dog eyes, despite there existing variances within each), while feature A can be mutated on or off on an individual level. In this case, we should expect the group where the group-level disease is also unprofitable to the individual, to outperform the group where the group-level disease is profitable to individuals, since feature A will be common in one group (which will suffer) and not the other (which will prosper). This is a way in which group selection can have meaningful effects while still having evolution act on individuals
Eliezer doesn’t say that it is impossible, only “pretty unlikely”. That is, under usual circumstances, when you do the math, the benefits of being a member of a tribe that benefits from group selection, although greater than zero, are much smaller than the individual benefits of defecting against the rest of the group.
This is the norm, in nature. This is what happens by default. The rare situations where this is not true, require special explanation. For example, ants or bees can collectively gather resources… but that is only possible because most of them are infertile children of the queen, so they cannot spread their genes better by defecting against the queen.
In your example, are the “groups” different species? In other words, is this about how bees would outperform bumblebees? In that case, the answer seems to be that the feature B itself is almost a miracle—something that turns a profitable behavior into inprofitable behavior, without being itself selected against by evolution… how would you do that?
(So how did bees evolve, if for their pre-bee ancestors, a worker being infertile was probably an evolutionary disadvantage? I have no idea. But the fact that there are only about three known examples in nature where this happened—ants, bees, naked mole-rats—suggests it was something pretty unlikely.)
Then you have humans, which are smart enough to recognize and collectively punish some activities that harm the group. If they keep doing so for generations, they can somewhat breed themselves towards harming the group less. But this is very slow and uncertain process, because the criminals are also smart enough to hide their actions, the enforcement has many loopholes (crimes are punished less if you are high-status, or if you do the thing to enemies), different societies have different norms, social order breaks down e.g. during wars, etc. So we get something like slightly fewer murders after a few centuries of civilization.
For example, ants or bees can collectively gather resources… but that is only possible because most of them are infertile children of the queen, so they cannot spread their genes better by defecting against the queen.
It’s worth noting that the infertility of worker bees is itself (seemingly) a form of genetic sacrifice, so it doesn’t really explain why cooperation evolved among bees. The explanation that I’m familiar with is that male bees (this is also true of ants, but not molerats) only have one set of genes, instead of the usual pair, which means that their daughters always inherit the same genetic material from the father. This means that in the case that two bees share both the same father and mother (which isn’t actually always the case in evolutionarily modern beehives, more thoughts on this later) then those bees will have 75% consanguity (improperly speaking, share 75% of their genes), whereas a mother bee only has 50% consanguinity with her own daughters (the same as between human siblings or between human parents and offspring). This means infertility can actually be a very effective strategy, and not at all altruistic, since a bee more effectively propogates her own genes by helping raise her younger (full) sisters than by raising children of her own.
But it’s worth noting that many haplodiploid species are not eusocial (for example wasps), and modern beehives often contain bees that have different fathers. Bees have the same consanguinity with half-siblings as humans have with their half-siblings (25%), and in principle, a bee should be able to better propagate her genes by having children of her own than by helping her half-siblings, yet we see bees helping raise their half-siblings all the time. While I wasn’t around to watch the evolution of bees myself, here’s one plausible story of how this situation could have come about:
In the original beehives, a mother bee would have several children with one father. Since bees are more closely related to their full siblings than to their own offspring, most of the female bees would spend more time helping raise their siblings than on having children themselves. At this point in the process, if a bee tried to raise a family with many different fathers, the household wouldn’t cohere very well, and would be outperformed by households (hiveholds?) with only a single father. We should expect that if we examined bee families in this early stage, we would see a noticeable bias towards families with one father (who likely played no role other than providing genetic information), and under this regime, something recognizeable as the eusocial beehives we know today would have been the result, just with one father instead of many, making every bee in the hive a full sibling of the other hivemates.
However, while having a singular father is conducive to eusociality, this actually poses a problem for the hive. To illustrate, you may be aware that the bananas we eat today aren’t the same bananas that used to be eaten 80 years ago; since we plant bananas in such a way that one banana is genetically identical to (has 100% consanguinity with) every other banana of the same cultivar, this makes them particularly vulnerable to infections and parasitism; the Gros Michel cultivar that used to be popular got entirely wiped out by a fungus, F. oxysporum cubense, referred to as Panama disease; the lack of genetic variety ensured that the moment a strain of F. oxysporum could infect one Gros Michel, it could run wild through every single Gros Michel in existence. Similarly, in a beehive containing tens of thousands of nearly identical bees, if a parasite or germ can infect one bee, it will spread like wildfire and destroy the hive.
This creates a conundrum for the hives: if it only takes genetic material from one father, it can easily be wiped out by disease; If it took genetic material from multiple fathers, any disease will likely only affect a fraction of the population, but there will be less incentive for the bees to take care of the hive. One semi-stable setup for a hive under these conditions may be for a hive to contain 3-6 different “clans” of bees with the same father (so a few different fathers for the whole hive). We would expect to see strong cooperation within each clan, but weak cooperation between clans (similar to how half-siblings usually interact). This would still provide much of the benefit of a homogenous beehive, but also ensure that the hive can survive after a given disease.
However, diseases would still cause problems as hive size increases, and from the perspective of the hive (as well as the individual in some circumstances), the decreased level of cooperation isn’t ideal. We should expect that if the bees are able to detect when a bee is defecting against the hive (either by trying to reproduce, or by trying to collect and reserve food for their own clan instead of the entire hive, or by any other possible way), it would be in a bee’s best interest to punish their half-siblings for defection, to help ensure that they contribute to the entire hive’s effort (we observe this happening in modern hives). Hives that have more robust traditions of detecting and punishing cheating would be able to outperform hives that don’t, by being able to maintain higher levels of cooperation even as the number of “clans” in the hive increases, thereby increasing resistance to disease, and thereby increasing the maximum size of the hive, while still being able to operate as a single organism.
Note that the entire evolutionary story above is made up, and I don’t claim to have any scientific or historic evidence backing it up, though it is roughly in line with my knowledge of evolutionary principles.
… Maybe I should just make this into a post. I didn’t realize I had so much to say on this topic.
I have often heard it pronounced (Including by Eliezer) that group selection is not a thing, that evolution never selects for “the good of the species”—and it is true, in the sense, that if evolution is given the chance to throw the species under the bus for a slight gain to the individual, then it will never hesitate to do so.
But there is a sense in which a group can be selected for—assume feature A is always bad for whichever species has it, and there are two species which occupy overlapping niches—one group with feature B, which makes feature A unprofitable for the individual, and one group with feature C, which makes feature A profitable for the individual. Assume features B and C are sufficiently complex that it remains constant within the group (there are many such biological traits—human eyes, for example, tend to be much more similar to eachother than to dog eyes, despite there existing variances within each), while feature A can be mutated on or off on an individual level. In this case, we should expect the group where the group-level disease is also unprofitable to the individual, to outperform the group where the group-level disease is profitable to individuals, since feature A will be common in one group (which will suffer) and not the other (which will prosper). This is a way in which group selection can have meaningful effects while still having evolution act on individuals
Eliezer doesn’t say that it is impossible, only “pretty unlikely”. That is, under usual circumstances, when you do the math, the benefits of being a member of a tribe that benefits from group selection, although greater than zero, are much smaller than the individual benefits of defecting against the rest of the group.
This is the norm, in nature. This is what happens by default. The rare situations where this is not true, require special explanation. For example, ants or bees can collectively gather resources… but that is only possible because most of them are infertile children of the queen, so they cannot spread their genes better by defecting against the queen.
In your example, are the “groups” different species? In other words, is this about how bees would outperform bumblebees? In that case, the answer seems to be that the feature B itself is almost a miracle—something that turns a profitable behavior into inprofitable behavior, without being itself selected against by evolution… how would you do that?
(So how did bees evolve, if for their pre-bee ancestors, a worker being infertile was probably an evolutionary disadvantage? I have no idea. But the fact that there are only about three known examples in nature where this happened—ants, bees, naked mole-rats—suggests it was something pretty unlikely.)
Then you have humans, which are smart enough to recognize and collectively punish some activities that harm the group. If they keep doing so for generations, they can somewhat breed themselves towards harming the group less. But this is very slow and uncertain process, because the criminals are also smart enough to hide their actions, the enforcement has many loopholes (crimes are punished less if you are high-status, or if you do the thing to enemies), different societies have different norms, social order breaks down e.g. during wars, etc. So we get something like slightly fewer murders after a few centuries of civilization.
It’s worth noting that the infertility of worker bees is itself (seemingly) a form of genetic sacrifice, so it doesn’t really explain why cooperation evolved among bees. The explanation that I’m familiar with is that male bees (this is also true of ants, but not molerats) only have one set of genes, instead of the usual pair, which means that their daughters always inherit the same genetic material from the father. This means that in the case that two bees share both the same father and mother (which isn’t actually always the case in evolutionarily modern beehives, more thoughts on this later) then those bees will have 75% consanguity (improperly speaking, share 75% of their genes), whereas a mother bee only has 50% consanguinity with her own daughters (the same as between human siblings or between human parents and offspring). This means infertility can actually be a very effective strategy, and not at all altruistic, since a bee more effectively propogates her own genes by helping raise her younger (full) sisters than by raising children of her own.
But it’s worth noting that many haplodiploid species are not eusocial (for example wasps), and modern beehives often contain bees that have different fathers. Bees have the same consanguinity with half-siblings as humans have with their half-siblings (25%), and in principle, a bee should be able to better propagate her genes by having children of her own than by helping her half-siblings, yet we see bees helping raise their half-siblings all the time. While I wasn’t around to watch the evolution of bees myself, here’s one plausible story of how this situation could have come about:
In the original beehives, a mother bee would have several children with one father. Since bees are more closely related to their full siblings than to their own offspring, most of the female bees would spend more time helping raise their siblings than on having children themselves. At this point in the process, if a bee tried to raise a family with many different fathers, the household wouldn’t cohere very well, and would be outperformed by households (hiveholds?) with only a single father. We should expect that if we examined bee families in this early stage, we would see a noticeable bias towards families with one father (who likely played no role other than providing genetic information), and under this regime, something recognizeable as the eusocial beehives we know today would have been the result, just with one father instead of many, making every bee in the hive a full sibling of the other hivemates.
However, while having a singular father is conducive to eusociality, this actually poses a problem for the hive. To illustrate, you may be aware that the bananas we eat today aren’t the same bananas that used to be eaten 80 years ago; since we plant bananas in such a way that one banana is genetically identical to (has 100% consanguinity with) every other banana of the same cultivar, this makes them particularly vulnerable to infections and parasitism; the Gros Michel cultivar that used to be popular got entirely wiped out by a fungus, F. oxysporum cubense, referred to as Panama disease; the lack of genetic variety ensured that the moment a strain of F. oxysporum could infect one Gros Michel, it could run wild through every single Gros Michel in existence. Similarly, in a beehive containing tens of thousands of nearly identical bees, if a parasite or germ can infect one bee, it will spread like wildfire and destroy the hive.
This creates a conundrum for the hives: if it only takes genetic material from one father, it can easily be wiped out by disease; If it took genetic material from multiple fathers, any disease will likely only affect a fraction of the population, but there will be less incentive for the bees to take care of the hive. One semi-stable setup for a hive under these conditions may be for a hive to contain 3-6 different “clans” of bees with the same father (so a few different fathers for the whole hive). We would expect to see strong cooperation within each clan, but weak cooperation between clans (similar to how half-siblings usually interact). This would still provide much of the benefit of a homogenous beehive, but also ensure that the hive can survive after a given disease.
However, diseases would still cause problems as hive size increases, and from the perspective of the hive (as well as the individual in some circumstances), the decreased level of cooperation isn’t ideal. We should expect that if the bees are able to detect when a bee is defecting against the hive (either by trying to reproduce, or by trying to collect and reserve food for their own clan instead of the entire hive, or by any other possible way), it would be in a bee’s best interest to punish their half-siblings for defection, to help ensure that they contribute to the entire hive’s effort (we observe this happening in modern hives). Hives that have more robust traditions of detecting and punishing cheating would be able to outperform hives that don’t, by being able to maintain higher levels of cooperation even as the number of “clans” in the hive increases, thereby increasing resistance to disease, and thereby increasing the maximum size of the hive, while still being able to operate as a single organism.
Note that the entire evolutionary story above is made up, and I don’t claim to have any scientific or historic evidence backing it up, though it is roughly in line with my knowledge of evolutionary principles.
… Maybe I should just make this into a post. I didn’t realize I had so much to say on this topic.