A Weakening of the gene pool

[NotAllThere]

What seemed to be a fruitless wibble seems to have turned into a in-depth discussion. I'm going to do some work instead.

[snaw]

Misconceptions all round.

1. 'Survival of the fittest' is not a moral judgement. The 'fittest' are not more 'fit' in any sense except that they are better suited than others to survive in a given environment. Different environments could have lead to different survival factors and so to different 'fittest'. There is nothing special about one environment over another: ask the dinosaurs. They were the fittest in one environment, but not in another.

2. 'Weakening' of the gene pool? What do you mean? No really, do you mean anything by that? Because you are showing a lamentable misunderstanding of the mechanism of evolution by natural selection:
(a) variation in the range of inheritable characteristics comes from somewhere. It doesn't matter where from; as it happens it is normally chance mutations.
This gives the raw material for the second aspect:
(b) natural selection. The 'fittest' survive and pass on their genetic material more than others, so they come to predominate.
Now you say, does the gene pool become 'weaker' (or 'shallower', NotAllThere) if elimination by selection does not happen? No, the opposite is true! If there is no natural selection to make the 'less fit' extinct, more variety remains in the gene pool. The gene pool is deeper and more varied if it is not selected.

IMHO you do not mean the gene pool, you just make a moral judgement on the value of the set of surviving individuals; that is not the same thing.

3. Evolution is not so much the survival of an individual, but the survival of characteristics in individuals, and the passage of these characteristics genetically by procreation. This latter is selected not only by natural selection (i.e. the more likely you are to survive = the more likely you are to have offspring), but also by sexual selection (i.e. you have to be attractive to potential mates if you want to have any offspring).
Sexual selection will still be operative, so humanity will just get better-looking as time goes by......

Great response!

Reckon this is one of my favourite CUK responses ever, informative, interesting and smacks down an ill informed question/opinion (OK a dro in the ocean here, but it's a start).

Nice one Expat!

[EternalOptimist]

Great response!

Reckon this is one of my favourite CUK responses ever, informative, interesting and smacks down an ill informed question/opinion (OK a dro in the ocean here, but it's a start).

Nice one Expat!

read my response snaw, check up on the screwfly principle, or I can explain it to you if you wish.

[snaw]

read my response snaw, check up on the screwfly principle, or I can explain it to you if you wish.

You see EO, expat put his argument forward lucidly, in an easy to understand, succint post. You asked us to go look up the screwfly principle - that involves more work on our part, so on that basis I'm out (And expat is the winner).

Anyway, it was his post I liked more than anything - it was interesting, and informative.

[expat]

Well some people might disagree with you there.
The fact that there was one person who had a genetic weakness, or disposition to a poorer immune system has led on to more , after breeding.
So we now have a group of people would are 'fit' only because they are propped up by technology.
do you understand how the 'screwfly principle' works ?

I don't understand its relevance here. Correction: I think I understand what you mean but I don't think it is relevant.

So some people are 'fit' only because they are propped up by technology. So what? 'Fit' in evolution is always and only a response to the environment. If the environment changes then the definition of 'fit' changes.

You're not talking about the gene pool, you're talking about your opinion that it's a bad thing that more people are dependent on technology to survive. Fine. But please don't think that you are talking about evolution. You are just making your own judgements of people's worth. Or drawing attention to the risk they face. Or whatever. You're not describing a 'weaker gene pool'. The only weaker gene pool is a poorer, less varied one.

It's a bit like lamenting that the dinosaurs died out, when they were still 'fit' to survive apart from those pesky catastrophic climate changes. But the comet did crash, the climate did change, the dinosaurs were no longer fit to survive in the new environment, and the tiny mammals were .... so here we are.

The people with genetic predisposition to weaker immune systems were less fit but now they are not. The environment changed. It could change again. Yes, they might then wiped out. Tough: that would be no loss to the gene pool, and there is no risk to the gene pool in having them in it. It is as I said a pool, not an average. If the environment does change (the technology goes away) then more of those people will die because they have survived only because of it. It's not a problem for the gene pool.

I'm sorry to rant, but you are expressing a fallacy. You are talking as if there is a 'natural' state where evolution works as it should, and we have abolished that. OK if you like, but leave evolution, selection, and gene pool out of it.

And if you insist on bringing the gene pool into it, I insist that a more varied gene pool (even with what you see as weaknesses) is if anything a stronger gene pool.

[EternalOptimist]

You see EO, expat put his argument forward lucidly, in an easy to understand, succint post. You asked us to go look up the screwfly principle - that involves more work on our part, so on that basis I'm out (And expat is the winner).

Anyway, it was his post I liked more than anything - it was interesting, and informative.

ok. I was enjoying talking to expat because he understands the subject.

Screwfly is a serious problem in some parts of the world and extremely difficult to control. One of the techniques used is to take a genetic condition, male sterility, and to produce millions of sterile males.
When these are released, the chances of a female mating with a potent male are minimal and so, next year, the screwfly population is tiny.


Now according to expat, we have stregnthened the screwfly genepool by introducing more variety and spreading it through the population?????

its obviously not doing the screwfly any favours, so why is it a good thing.

[EternalOptimist]

I don't understand its relevance here. Correction: I think I understand what you mean but I don't think it is relevant.

So some people are 'fit' only because they are propped up by technology. So what? 'Fit' in evolution is always and only a response to the environment. If the environment changes then the definition of 'fit' changes.

You're not talking about the gene pool, you're talking about your opinion that it's a bad thing that more people are dependent on technology to survive. Fine. But please don't think that you are talking about evolution. You are just making your own judgements of people's worth. Or drawing attention to the risk they face. Or whatever. You're not describing a 'weaker gene pool'. The only weaker gene pool is a poorer, less varied one.

It's a bit like lamenting that the dinosaurs died out, when they were still 'fit' to survive apart from those pesky catastrophic climate changes. But the comet did crash, the climate did change, the dinosaurs were no longer fit to survive in the new environment, and the tiny mammals were .... so here we are.

The people with genetic predisposition to weaker immune systems were less fit but now they are not. The environment changed. It could change again. Yes, they might then wiped out. Tough: that would be no loss to the gene pool, and there is no risk to the gene pool in having them in it. It is as I said a pool, not an average. If the environment does change (the technology goes away) then more of those people will die because they have survived only because of it. It's not a problem for the gene pool.

I'm sorry to rant, but you are expressing a fallacy. You are talking as if there is a 'natural' state where evolution works as it should, and we have abolished that. OK if you like, but leave evolution, selection, and gene pool out of it.

And if you insist on bringing the gene pool into it, I insist that a more varied gene pool (even with what you see as weaknesses) is if anything a stronger gene pool.

er sorry. I dont have an opinion. or a position.

just a discussion for a slowww wednesday afternoon

[snaw]

ok. I was enjoying talking to expat because he understands the subject.

Clearly I don't so think of me as Simon Cowell, and you can be the hairy angel. Not sure who that makes expat.

[expat]

...
Now according to expat, we have stregnthened the screwfly genepool by introducing more variety and spreading it through the population?????

its obviously not doing the screwfly any favours, so why is it a good thing.

Ah. Aaaaah. That's a good question.

Could I say that you might strengthen the gene pool while eliminating the species? No, I suppose not.

Next year, the screwfly population may be tiny, but it will not contain the sterility gene (obviously). So that has selected itself right out in one generation. That actually doesn't differ from what I'm saying. A characteristic is selected for or against, or it is not. If it is not selected either way then it is irrelevant (for the moment: it may turn out to be important later in a different environment). If it is selected against, it disappears: like the screwfly sterility, and like the immune system weakness in previous times, but unlike that weakness now. There is no inconsistency there: there is only the personal opinion that it might be a bad thing that it is no longer selected against. But like I said, changes in environment happen, and changes in selection with it.

[EternalOptimist]

Ah. Aaaaah. That's a good question.

Could I say that you might strengthen the gene pool while eliminating the species? No, I suppose not.

Next year, the screwfly population may be tiny, but it will not contain the sterility gene (obviously). So that has selected itself right out in one generation. That actually doesn't differ from what I'm saying. A characteristic is selected for or against, or it is not. If it is not selected either way then it is irrelevant (for the moment: it may turn out to be important later in a different environment). If it is selected against, it disappears: like the screwfly sterility, and like the immune system weakness in previous times, but unlike that weakness now. There is no inconsistency there: there is only the personal opinion that it might be a bad thing that it is no longer selected against. But like I said, changes in environment happen, and changes in selection with it.

ok.
So you have the situation where the poor immune system gene is allowed to propogate through the population, which is propped up by technology.
The prop gets kicked away.
A population CAN become too tiny.

goto OP