6 ms·

According to the gene shortage argument, genes can’t be very important to the birth of the mind because the genome contains only about 30,000 genes, simply too

by lacker 7y ago

According to the gene shortage argument, genes can’t be very important to the birth of the mind because the genome contains only about 30,000 genes, simply too few to account even for the brain’s complexity—with its billions of cells and tens of billions of connections between neurons—much less the mind’s. “Given that ratio,” Ehrlich suggested, “it would be quite a trick for genes typically to control more than the most general aspects of human behavior.” To me, the clearest argument against this position is that horses can walk within a couple hours after being born. That doesn't seem like anywhere near enough trials to learn how to walk from first principles. The method to walk must be encoded in the horse's DNA. Humans can't walk at birth, obviously. But Occam's Razor suggests that if the ability to walk can be encoded within a horse's DNA, it can also be encoded within a human's DNA. Anecdotally, when I watch a baby learn to walk, it doesn't really seem like they are trying a zillion things and picking the one that works. It seems much more like their instincts are telling them to move a certain way, and once they grow strong enough, it succeeds and they are walking.

ksdale 7y ago
It's hard to separate out what is a lack of strength or coordination and what is random trial. When babies learn to do basically everything, they do a tremendous amount of random flailing that gradually (over weeks or months or years) resolves into the thing they're trying to accomplish. I think some people interpret this as babies just becoming strong enough to do things they innately know how to do, but with my 4 children, it's always struck me as learning through trial and error, like the neurons and muscle fibers gradually form in a way that is something like the average of all the ways they tried to achieve a goal. That's just my perception, of course. But then I also agree that babies seem to come pre-programmed with a desire to attempt a whole bunch of things. Like I said, I think it's very difficult to separate these things out!
- deleted 7y ago
  [deleted]
Erlich_Bachman 7y ago
> According to the gene shortage argument, genes can’t be very important to the birth of the mind because the genome contains only about 30,000 genes, simply too few to account even for the brain’s complexity—with its billions of cells and tens of billions of connections between neurons—much less the mind’s. “Given that ratio,” Ehrlich suggested, “it would be quite a trick for genes typically to control more than the most general aspects of human behavior.” Yes, even regardless of other examples you have provided, that's just basically bad poor logic in the article? Why would anyone assume that the number of connections of neurons would need to linearly relate to the number of genes describing them? What if a couple of genes describe a process that is then repeated for a billion times during development?
- jhedwards 7y ago
  The article presents this idea specifically because it is incorrect, and goes on to explain the newer, more accurate understanding of genes, which is (as far as I understand it) that they encode various options and patterns that can be leveraged by the organism in different situations, not a rigid plan to be executed by the cells.
  - asdaddasdad 7y ago
    I don't understand why that is supposed to be a "new understanding". I think it was the understanding all along (or at least most of the time). Isn't even the famous moth that changed color in the early days of the industrial evolution an example? I think it carries both genes (for black and white expression), and they get triggered depending on the environment during development. https://en.wikipedia.org/wiki/Peppered_moth_evolution https://en.wikipedia.org/wiki/Peppered_moth_evolution I could be wrong about the moth, but certainly, genes that are only expressed depending on environment are common knowledge.
maxerickson 7y ago
Humans are born extremely early relative to other mammals, because of our relatively narrow hips and relatively large brains.
munchbunny 7y ago
> Anecdotally, when I watch a baby learn to walk, it doesn't really seem like they are trying a zillion things and picking the one that works. It seems much more like their instincts are telling them to move a certain way, and once they grow strong enough, it succeeds and they are walking. How much of that comes from seeing everyone around them walking? It seems hard to argue that horses don't have a genetic component, but I don't think Occam's Razor applies as well for humans when it takes 1-2 years of observing the world in order to start walking unsteadily.
- bolzano 7y ago
  The obvious counter to this argument is that blind babies follow roughly (often slightly delayed) the same developmental pattern and stages as sighted children, with the mostly likely cause of the delay being motivational rather than anything to do with processing visual imagery of what walking/crawling looks like. Both are usually crawling in 6-12 month range.
  - munchbunny 7y ago
    I don't doubt your claim, but do you have the academic references for that covering the timeline of development milestones? I'd be curious to read more of this research.
    - bolzano 7y ago
      I'm not an expert in this area, though I do have a strong interest in more abstract child cognitive development not related to locomotion (Elizabeth Spelke and related work in particular). So I'm going by what is generally well known and accepted about visually impaired development (the time line and stages). Here are a couple of references below which might be helpful. Infant development is a pretty noisy process though which makes definitive statements difficult. [0] https://onlinelibrary.wiley.com/doi/pdf/10.1111/dmcn.12860 https://onlinelibrary.wiley.com/doi/pdf/10.1111/dmcn.12860 [1] https://www.tsbvi.edu/curriculum-a-publications/1053-early-development https://www.tsbvi.edu/curriculum-a-publications/1053-early-d...
HorizonXP 7y ago
I'm going to provide some anecdata. As a new father, you get to talking with a number of new parents too, with kids that are similar in age to your own. One of the potential downsides to this is that when you talk about your kids, you start to compare them to each other and create a competition where none should exist. It's hard, but as a new parent, you should really try to avoid this and instead focus on nurturing your child to be the best he/she can be. (Aside: what's the currently accepted pronoun there? I was always taught "they" is incorrect grammar, but without devolving this discussion, that seems to be accepted now?) My son is 13 months old now, and crawls like a maniac, ever since he was roughly 5 months old. Very social, talkative, active, all those good things. Pulls up and stands all the time, can climb in and out of toy vehicles, climbs stairs, all of that. When I hold him while he stands, he is barely putting any weight on me. Even if he's not walking, he should be able to stand on his own. But he doesn't, and he absolutely refuses to do so. He sees cousins and other big kids walking, and isn't afraid to crawl to them and play, but it doesn't inspire him to walk. We know a lot of other kids that are younger than him, his age, or a few months older, and they are walking. He's stronger and more capable than them, but they're walking and he isn't. My wife and I comment on this fact all the time, about how it seems that walking has nothing to do with strength, and it's more about readiness. I doubt that my son isn't walking because he's not strong enough, nor is it because he doesn't have a good environment, save for the fact that I'm not pushing him to walk (i.e. I'm enjoying the calm before the storm.) Readiness for walking is definitely dependent on a number of factors, but I'm willing to bet that genetics is a big part of it too. Apparently I didn't really walk until I was 2 years old. Babies and walking is a very interesting phenomenon that really lets you see into the working of genetics and environment.
- automatoney 7y ago
  Quick reply to your aside: singular they is very grammatical and has been in use for centuries. From Merriam-Webster: "they has been in consistent use as a singular pronoun since the late 1300s; that the development of singular they mirrors the development of the singular you from the plural you... and that regardless of what detractors say, nearly everyone uses the singular they in casual conversation and often in formal writing."[1] [1] https://www.merriam-webster.com/words-at-play/singular-nonbinary-they https://www.merriam-webster.com/words-at-play/singular-nonbi...
aeternum 7y ago
The benefit of a neural net and reinforcement learning is that genes don't have to encode the connections. They can instead encode the reward function(s), and some of this training can occur in the womb, this is probably why babies 'kick' while gestating. You could imagine a hierarchy that goes something like this: - Reward neurons that successfully transmit signal from brain to muscle fiber - Reward neuron groups that get co-located muscle fibers to fire together. Now the next levels can operate on muscles as a group (calf/hamstring) rather than individual fibers: - Reward neuron groups that sense balance - Reward neuron groups that move a muscle in response to balance output. Believing that genes have to operate at the level of individual neuron connections to shape behavior just doesn't make sense.
api 7y ago
> The method to walk must be encoded in the horse's DNA. A bodily and neurological structure capable of walking must emerge in the horse's phenotype as a result of development in the horse's environment guided by its genes. It sounds like the same thing, but it's not. Genes do not encode anything explicit except RNA and protein sequences. Everything else is emergent. They are not a blueprint. Birth a horse on the Moon and I'm not sure if it would be able to walk as quickly.
buboard 7y ago
Not in their DNA, but in the wiring of motoneurons: walking is facilitated by passive central pattern generators and the action of agonist/antagonist muscles. A deafferented cat can still do the walking pattern . But it's true, our DNA encodes so many things that facilitate learning.
- esyir 7y ago
  That would be in the DNA though. Our physiological structure emerges from that.
  - buboard 7y ago
    oh yes that's true. I should have said "not in the brain"

by lacker 7y ago

ksdale 7y ago

It's hard to separate out what is a lack of strength or coordination and what is random trial. When babies learn to do basically everything, they do a tremendous amount of random flailing that gradually (over weeks or months or years) resolves into the thing they're trying to accomplish. I think some people interpret this as babies just becoming strong enough to do things they innately know how to do, but with my 4 children, it's always struck me as learning through trial and error, like the neurons and muscle fibers gradually form in a way that is something like the average of all the ways they tried to achieve a goal. That's just my perception, of course. But then I also agree that babies seem to come pre-programmed with a desire to attempt a whole bunch of things. Like I said, I think it's very difficult to separate these things out!

deleted 7y ago
[deleted]

Erlich_Bachman 7y ago

> According to the gene shortage argument, genes can’t be very important to the birth of the mind because the genome contains only about 30,000 genes, simply too few to account even for the brain’s complexity—with its billions of cells and tens of billions of connections between neurons—much less the mind’s. “Given that ratio,” Ehrlich suggested, “it would be quite a trick for genes typically to control more than the most general aspects of human behavior.” Yes, even regardless of other examples you have provided, that's just basically bad poor logic in the article? Why would anyone assume that the number of connections of neurons would need to linearly relate to the number of genes describing them? What if a couple of genes describe a process that is then repeated for a billion times during development?

jhedwards 7y ago
The article presents this idea specifically because it is incorrect, and goes on to explain the newer, more accurate understanding of genes, which is (as far as I understand it) that they encode various options and patterns that can be leveraged by the organism in different situations, not a rigid plan to be executed by the cells.
- asdaddasdad 7y ago
  I don't understand why that is supposed to be a "new understanding". I think it was the understanding all along (or at least most of the time). Isn't even the famous moth that changed color in the early days of the industrial evolution an example? I think it carries both genes (for black and white expression), and they get triggered depending on the environment during development. https://en.wikipedia.org/wiki/Peppered_moth_evolution https://en.wikipedia.org/wiki/Peppered_moth_evolution I could be wrong about the moth, but certainly, genes that are only expressed depending on environment are common knowledge.

maxerickson 7y ago

Humans are born extremely early relative to other mammals, because of our relatively narrow hips and relatively large brains.

munchbunny 7y ago

> Anecdotally, when I watch a baby learn to walk, it doesn't really seem like they are trying a zillion things and picking the one that works. It seems much more like their instincts are telling them to move a certain way, and once they grow strong enough, it succeeds and they are walking. How much of that comes from seeing everyone around them walking? It seems hard to argue that horses don't have a genetic component, but I don't think Occam's Razor applies as well for humans when it takes 1-2 years of observing the world in order to start walking unsteadily.

bolzano 7y ago
The obvious counter to this argument is that blind babies follow roughly (often slightly delayed) the same developmental pattern and stages as sighted children, with the mostly likely cause of the delay being motivational rather than anything to do with processing visual imagery of what walking/crawling looks like. Both are usually crawling in 6-12 month range.
- munchbunny 7y ago
  I don't doubt your claim, but do you have the academic references for that covering the timeline of development milestones? I'd be curious to read more of this research.
  - bolzano 7y ago
    I'm not an expert in this area, though I do have a strong interest in more abstract child cognitive development not related to locomotion (Elizabeth Spelke and related work in particular). So I'm going by what is generally well known and accepted about visually impaired development (the time line and stages). Here are a couple of references below which might be helpful. Infant development is a pretty noisy process though which makes definitive statements difficult. [0] https://onlinelibrary.wiley.com/doi/pdf/10.1111/dmcn.12860 https://onlinelibrary.wiley.com/doi/pdf/10.1111/dmcn.12860 [1] https://www.tsbvi.edu/curriculum-a-publications/1053-early-development https://www.tsbvi.edu/curriculum-a-publications/1053-early-d...

HorizonXP 7y ago

I'm going to provide some anecdata. As a new father, you get to talking with a number of new parents too, with kids that are similar in age to your own. One of the potential downsides to this is that when you talk about your kids, you start to compare them to each other and create a competition where none should exist. It's hard, but as a new parent, you should really try to avoid this and instead focus on nurturing your child to be the best he/she can be. (Aside: what's the currently accepted pronoun there? I was always taught "they" is incorrect grammar, but without devolving this discussion, that seems to be accepted now?) My son is 13 months old now, and crawls like a maniac, ever since he was roughly 5 months old. Very social, talkative, active, all those good things. Pulls up and stands all the time, can climb in and out of toy vehicles, climbs stairs, all of that. When I hold him while he stands, he is barely putting any weight on me. Even if he's not walking, he should be able to stand on his own. But he doesn't, and he absolutely refuses to do so. He sees cousins and other big kids walking, and isn't afraid to crawl to them and play, but it doesn't inspire him to walk. We know a lot of other kids that are younger than him, his age, or a few months older, and they are walking. He's stronger and more capable than them, but they're walking and he isn't. My wife and I comment on this fact all the time, about how it seems that walking has nothing to do with strength, and it's more about readiness. I doubt that my son isn't walking because he's not strong enough, nor is it because he doesn't have a good environment, save for the fact that I'm not pushing him to walk (i.e. I'm enjoying the calm before the storm.) Readiness for walking is definitely dependent on a number of factors, but I'm willing to bet that genetics is a big part of it too. Apparently I didn't really walk until I was 2 years old. Babies and walking is a very interesting phenomenon that really lets you see into the working of genetics and environment.

automatoney 7y ago
Quick reply to your aside: singular they is very grammatical and has been in use for centuries. From Merriam-Webster: "they has been in consistent use as a singular pronoun since the late 1300s; that the development of singular they mirrors the development of the singular you from the plural you... and that regardless of what detractors say, nearly everyone uses the singular they in casual conversation and often in formal writing."[1] [1] https://www.merriam-webster.com/words-at-play/singular-nonbinary-they https://www.merriam-webster.com/words-at-play/singular-nonbi...

aeternum 7y ago

The benefit of a neural net and reinforcement learning is that genes don't have to encode the connections. They can instead encode the reward function(s), and some of this training can occur in the womb, this is probably why babies 'kick' while gestating. You could imagine a hierarchy that goes something like this: - Reward neurons that successfully transmit signal from brain to muscle fiber - Reward neuron groups that get co-located muscle fibers to fire together. Now the next levels can operate on muscles as a group (calf/hamstring) rather than individual fibers: - Reward neuron groups that sense balance - Reward neuron groups that move a muscle in response to balance output. Believing that genes have to operate at the level of individual neuron connections to shape behavior just doesn't make sense.

api 7y ago

> The method to walk must be encoded in the horse's DNA. A bodily and neurological structure capable of walking must emerge in the horse's phenotype as a result of development in the horse's environment guided by its genes. It sounds like the same thing, but it's not. Genes do not encode anything explicit except RNA and protein sequences. Everything else is emergent. They are not a blueprint. Birth a horse on the Moon and I'm not sure if it would be able to walk as quickly.

buboard 7y ago

Not in their DNA, but in the wiring of motoneurons: walking is facilitated by passive central pattern generators and the action of agonist/antagonist muscles. A deafferented cat can still do the walking pattern . But it's true, our DNA encodes so many things that facilitate learning.

esyir 7y ago
That would be in the DNA though. Our physiological structure emerges from that.
- buboard 7y ago
  oh yes that's true. I should have said "not in the brain"