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Survival unit and evolution

rross
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7/4/2016 5:58:33 PM
Posted: 5 months ago
So, with evolution, I'm thinking it doesn't make sense to think of units as defined by discrete bodies, but rather as the minimum amount of a species required for reproduction and survival. An ant colony, for example, is the basic unit of ant, since a drone can't survive and reproduce in its own. Similarly with humans, the unit we should consider is a group of humans. Like, in the jungle you might come across a troop of monkeys. Then, the individual humans within the group can be considered as parts of the working whole.

I think, the reason we don't think that way is because we have a strong sense of self in opposition to other individuals, but that is itself an evolved mechanism of thought. Like, each part needs to be self-referencing in order to coordinate with the other parts. That's our mental bias.
keithprosser
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7/4/2016 6:39:51 PM
Posted: 5 months ago
Dawkins wasn't the first to suggest it (but he popularised it in his great book 'The Selfish Gene') that the unit of survival and evolution is the gene. That is a view held by most biologists, although it as a few, albeit prominent, dissenters who favour variants of 'group selection'. I can't find any notable biologists who put the individual organism front and centre.

On the gene-centred view of evolution an organism is a machine built by teams of genes to propagate themselves. Genes only 'care' about their own survival (or the survival of their copies). Survival of their containing organism is secondary and incidental to the genes 'selfish' concern with propagating themselves - hence 'selfish gene'; it is nothing to do with a gene for being selfish.

I could paraphrase the relevant wikipedia article, but its easier to link to it!
https://en.wikipedia.org...
Even better would be to read 'The Selfish Gene' - essential reading for any educated person in my view and far, far better than the frankly awful 'God Delusion'... but I digress.
rross
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7/4/2016 6:52:46 PM
Posted: 5 months ago
At 7/4/2016 6:39:51 PM, keithprosser wrote:
Dawkins wasn't the first to suggest it (but he popularised it in his great book 'The Selfish Gene') that the unit of survival and evolution is the gene. That is a view held by most biologists, although it as a few, albeit prominent, dissenters who favour variants of 'group selection'. I can't find any notable biologists who put the individual organism front and centre.

On the gene-centred view of evolution an organism is a machine built by teams of genes to propagate themselves. Genes only 'care' about their own survival (or the survival of their copies). Survival of their containing organism is secondary and incidental to the genes 'selfish' concern with propagating themselves - hence 'selfish gene'; it is nothing to do with a gene for being selfish.

I could paraphrase the relevant wikipedia article, but its easier to link to it!
https://en.wikipedia.org...
Even better would be to read 'The Selfish Gene' - essential reading for any educated person in my view and far, far better than the frankly awful 'God Delusion'... but I digress.

Thanks, yes, I have read it but a long time ago and I can't remember the details. I don't know enough about genetics, but it seems a bit reductionist to think of all these genes operating independently? Obviously, they wouldn't be...?
keithprosser
Posts: 1,965
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7/4/2016 7:18:07 PM
Posted: 5 months ago
Thanks, yes, I have read it but a long time ago and I can't remember the details. I don't know enough about genetics, but it seems a bit reductionist to think of all these genes operating independently? Obviously, they wouldn't be...?

An analogy might be a professional soccer player. That player wants to maximise his own salary, but has to operate within a team setting to do that. A degree of co-operation pays off whereas operating purely independently would not pay off at all. Of course genes are not capable of conscious thought (see? They are just like soccer players!) and don't 'decide' to co-operate - it is natural selection operating at the lowest level that makes the most successful genes prosper, and it is those genes that happen to co-operate that win out.

As in the 'real world' selfishness can be self-defeating if it goes too far. The Selfish gene concept is a hyper-reductionist interpretation but I think it works very well as an explanatory framework.

PS Download SG from here - I don't think Dawkin's will miss the royalties on one missed sale.
http://www.pdf-archive.com...
rross
Posts: 2,772
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7/5/2016 11:05:15 AM
Posted: 5 months ago
At 7/4/2016 7:18:07 PM, keithprosser wrote:
Thanks, yes, I have read it but a long time ago and I can't remember the details. I don't know enough about genetics, but it seems a bit reductionist to think of all these genes operating independently? Obviously, they wouldn't be...?

An analogy might be a professional soccer player. That player wants to maximise his own salary, but has to operate within a team setting to do that. A degree of co-operation pays off whereas operating purely independently would not pay off at all. Of course genes are not capable of conscious thought (see? They are just like soccer players!) and don't 'decide' to co-operate - it is natural selection operating at the lowest level that makes the most successful genes prosper, and it is those genes that happen to co-operate that win out.

As in the 'real world' selfishness can be self-defeating if it goes too far. The Selfish gene concept is a hyper-reductionist interpretation but I think it works very well as an explanatory framework.

PS Download SG from here - I don't think Dawkin's will miss the royalties on one missed sale.
http://www.pdf-archive.com...

I suppose the missing part might be gene expression? I was reading about these monkeys who are cooperative breeders, and when a monkey reaches dominance status in the group, she changes physiologically. She grows, her brain grows, her behavior changes, and she starts being super-fertile. It's a sorta monkey version of the insect colony, where different roles are assigned and then the appropriate genes express themselves according to the roles and circumstances. Presumably, every monkey in the group has similar DNA, but the subordinate monkeys (actually, maybe it was marmosets come to think of it) are infertile. Their alpha-female genes are dormant.

So it's the same genes, but different group roles. That is, the genes have to cater for specialization within the group.
keithprosser
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7/5/2016 11:47:55 AM
Posted: 5 months ago
From what learned in university, sorry, off the internet about marmosets I would doubt that it is genes actually gettimg switched on and off. The changes are more likely to be hormonal.... but what do I know? Marmoset reproductive strategy is not my speciality!

The basis of the SG idea is to invert the usual idea that organisms use genes to reproduce - the SG view says that genes use organisms to reproduce. Why not? it is genes that mutate to get evolution started. The varous mutant forms of genes then slug it out natural-selection style via their enclosing organisms.

The SG model is very good for explaining the emergence of altruism, for example. Altruism makes little sense in terms of benefit to the sacrificing individual, but altruism can make sense if one gene (in the sacrificing individual) is lost for the good of multiple copies of itself.

Sadly, there is no way I can precis a 200+ page book in a post!
rross
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7/5/2016 12:23:12 PM
Posted: 5 months ago
At 7/5/2016 11:47:55 AM, keithprosser wrote:
From what learned in university, sorry, off the internet about marmosets I would doubt that it is genes actually gettimg switched on and off. The changes are more likely to be hormonal.... but what do I know? Marmoset reproductive strategy is not my speciality!

Yeah, I'm very vague about biology. But wouldn't the genes code for hormone production? There are probably all kinds of intervening processes, but functionally speaking, certain hormones are produced in dominant circumstances and others in submissive circumstances. That's coded for, somehow, in the genes - although, the metaphor of "coding" seems really fake, doesn't it? But that's the framework that I learned, off the internet haha. Even if the process that recognizes status and determines hormone release from that is not about gene expression, the genes are "coded" for those two scenarios, right?

The basis of the SG idea is to invert the usual idea that organisms use genes to reproduce - the SG view says that genes use organisms to reproduce. Why not? it is genes that mutate to get evolution started. The varous mutant forms of genes then slug it out natural-selection style via their enclosing organisms.

The SG model is very good for explaining the emergence of altruism, for example. Altruism makes little sense in terms of benefit to the sacrificing individual, but altruism can make sense if one gene (in the sacrificing individual) is lost for the good of multiple copies of itself.

Sadly, there is no way I can precis a 200+ page book in a post!

No. It makes sense what you're saying. I guess the thing is, it's not as if there's a one to one relationship between genes and behaviors so it's not as if genetics helps out much for understanding behavior.

Since we're talking about monkeys, if a monkey gives her child some food, obviously she wouldn't do that if the child wasn't there taking the food. So you could characterize that action as two behaviours, one giving, one receiving. Or it could just be the movement of resources within the system. One action. It's the same thing. I suppose it doesn't really matter, just that people seem to rather arbitrarily prefer the former and I was wondering about why.

But maybe they don't? Maybe that's just me.
Skepsikyma
Posts: 8,280
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7/5/2016 9:37:54 PM
Posted: 5 months ago
At 7/4/2016 5:58:33 PM, rross wrote:
So, with evolution, I'm thinking it doesn't make sense to think of units as defined by discrete bodies, but rather as the minimum amount of a species required for reproduction and survival. An ant colony, for example, is the basic unit of ant, since a drone can't survive and reproduce in its own. Similarly with humans, the unit we should consider is a group of humans. Like, in the jungle you might come across a troop of monkeys. Then, the individual humans within the group can be considered as parts of the working whole.

I think, the reason we don't think that way is because we have a strong sense of self in opposition to other individuals, but that is itself an evolved mechanism of thought. Like, each part needs to be self-referencing in order to coordinate with the other parts. That's our mental bias.

Yeah, group-level evolution definitely plays into botany very strongly. Plants, being immobile, easily form genetically similar communities and differentiate by geographical location.

Ant colonies can basically be thought of as one large decision-making apparatus as well, so their collective learned behavior and interaction with the environment plays really heavily into things like mutualism.
"The Collectivist experiment is thoroughly suited (in appearance at least) to the Capitalist society which it proposes to replace. It works with the existing machinery of Capitalism, talks and thinks in the existing terms of Capitalism, appeals to just those appetites which Capitalism has aroused, and ridicules as fantastic and unheard-of just those things in society the memory of which Capitalism has killed among men wherever the blight of it has spread."
- Hilaire Belloc -