most of the genome is junk. That’s pretty strong evidence that the size of the genome is not itself a taut constraint.
My guess is that this is a total misunderstanding of what’s meant by “genomic bottleneck”. The bottleneck isn’t the amount of information storage, it’s the fact that the genome can only program the mind in a very indirect, developmental way, so that it can install stuff like “be more interested in people” but not “here’s how to add numbers”.
That seems wrong, living creatures have lots of specific behaviors that are genetically programmed.
In fact I think both you and John are misunderstanding the bottleneck. The point isn’t that the genome is small, nor that it affects the mind indirectly. The point is that the mind doesn’t affect the genome. Living creatures don’t have the tech to encode their life experience into genes for the next generation.
I’ve appreciated this comment thread! My take is that you’re all talking about different relevant things. It may well be the case that there are multiple reasons why more skills and knowledge aren’t encoded in our genomes: a) it’s hard to get that information in (from parents’ brains), b) it’s hard to get that information out (to childrens’ brains), and c) having large genomes is costly. What I’m calling the genomic bottleneck is a combination of all of them (although I think John is probably right that c) is not the main reason).
What would falsify my claim about the genomic bottleneck is if the main reason there isn’t more information passed on via genomes is because d) doing so is not very useful. That seems pretty unlikely, but not entirely out of the picture. E.g. we know that evolution is able to give baby deer the skill of walking shortly after birth, so it seems like d) might be the best explanation of why humans can’t do that too. But deer presumably evolved that skill over a very long time period, whereas I’m more interested in rapid changes.
Do you think you can encode good flint-knapping technique genetically? I doubt that.
I think I agree with your point, and think it’s a more general and correct statement of the bottleneck; but, still, I think that genome does mainly affect the mind indirectly, and this is one of the constraints making it be the case that humans have lots of learning / generalizing capability. (This doesn’t just apply to humans. What are some stark examples of animals with hardwired complex behaviors? With a fairly high bar for “complex”, and a clear explanation of what is hardwired and how we know. Insects have some fairly complex behaviors, e.g. web building, ant-hill building, the tree-leaf nests of weaver ants, etc.; but IDK enough to rule out a combination of a little hardwiring, some emergence, and some learning. Lots of animals hunt after learning from their parents how to hunt. I think a lot of animals can walk right after being born? I think beavers in captivity will fruitlessly chew on wood, indicating that the wild phenotype is encoded by something simple like “enjoys chewing” (plus, learned desire for shelter), rather than “use wood for dam”.)
An operationalization of “the genome directly programs the mind” would be that things like [the motions employed in flint-knapping] can be hardwired by small numbers of mutations (and hence can be evolved given a few million relevant years). I think this isn’t true, but counterevidence would be interesting. Since the genome can’t feasibly directly encode behaviors, or at least can’t learn those quickly enough to keep up with a changing niche, the species instead evolves to learn behaviors on the fly via algorithms that generalize. If there were *either* mind-mind transfer, *or* direct programming of behavior by the genome, then higher frequency changes would be easier and there’d be less need for fluid intelligence. (In fact it’s sort of plausible to me (given my ignorance) that humans are imitation specialists and are less clever than Neanderthals were, since mind-mind transfer can replace intelligence.)
Some animal behaviours are certainly hardwired. There is the famous case of one bee species being immune to a pathogen because of a specific cleaning behaviour that is encoded by a single gene.
One important point that should be brought up in this context is sexual recombination.
if you have a part of a genome encoding a complex behaviour it can get reshuffled in the new generation. You would need some pretty powerful error correcting code to keep things working.
My guess is that this is a total misunderstanding of what’s meant by “genomic bottleneck”. The bottleneck isn’t the amount of information storage, it’s the fact that the genome can only program the mind in a very indirect, developmental way, so that it can install stuff like “be more interested in people” but not “here’s how to add numbers”.
That seems wrong, living creatures have lots of specific behaviors that are genetically programmed.
In fact I think both you and John are misunderstanding the bottleneck. The point isn’t that the genome is small, nor that it affects the mind indirectly. The point is that the mind doesn’t affect the genome. Living creatures don’t have the tech to encode their life experience into genes for the next generation.
I’ve appreciated this comment thread! My take is that you’re all talking about different relevant things. It may well be the case that there are multiple reasons why more skills and knowledge aren’t encoded in our genomes: a) it’s hard to get that information in (from parents’ brains), b) it’s hard to get that information out (to childrens’ brains), and c) having large genomes is costly. What I’m calling the genomic bottleneck is a combination of all of them (although I think John is probably right that c) is not the main reason).
What would falsify my claim about the genomic bottleneck is if the main reason there isn’t more information passed on via genomes is because d) doing so is not very useful. That seems pretty unlikely, but not entirely out of the picture. E.g. we know that evolution is able to give baby deer the skill of walking shortly after birth, so it seems like d) might be the best explanation of why humans can’t do that too. But deer presumably evolved that skill over a very long time period, whereas I’m more interested in rapid changes.
Do you think you can encode good flint-knapping technique genetically? I doubt that.
I think I agree with your point, and think it’s a more general and correct statement of the bottleneck; but, still, I think that genome does mainly affect the mind indirectly, and this is one of the constraints making it be the case that humans have lots of learning / generalizing capability. (This doesn’t just apply to humans. What are some stark examples of animals with hardwired complex behaviors? With a fairly high bar for “complex”, and a clear explanation of what is hardwired and how we know. Insects have some fairly complex behaviors, e.g. web building, ant-hill building, the tree-leaf nests of weaver ants, etc.; but IDK enough to rule out a combination of a little hardwiring, some emergence, and some learning. Lots of animals hunt after learning from their parents how to hunt. I think a lot of animals can walk right after being born? I think beavers in captivity will fruitlessly chew on wood, indicating that the wild phenotype is encoded by something simple like “enjoys chewing” (plus, learned desire for shelter), rather than “use wood for dam”.)
An operationalization of “the genome directly programs the mind” would be that things like [the motions employed in flint-knapping] can be hardwired by small numbers of mutations (and hence can be evolved given a few million relevant years). I think this isn’t true, but counterevidence would be interesting. Since the genome can’t feasibly directly encode behaviors, or at least can’t learn those quickly enough to keep up with a changing niche, the species instead evolves to learn behaviors on the fly via algorithms that generalize. If there were *either* mind-mind transfer, *or* direct programming of behavior by the genome, then higher frequency changes would be easier and there’d be less need for fluid intelligence. (In fact it’s sort of plausible to me (given my ignorance) that humans are imitation specialists and are less clever than Neanderthals were, since mind-mind transfer can replace intelligence.)
Some animal behaviours are certainly hardwired. There is the famous case of one bee species being immune to a pathogen because of a specific cleaning behaviour that is encoded by a single gene.
One important point that should be brought up in this context is sexual recombination.
if you have a part of a genome encoding a complex behaviour it can get reshuffled in the new generation. You would need some pretty powerful error correcting code to keep things working.