Split Thread: Role of reproduction or survival in evolution

[Bill Thompson 75]

Originally Posted by Dancing David

Small quiblle: the word 'goal'.

Goals may be nutrition, environment, concealment, etc. which are sought by nearly all life forms from the microscopic to the largest.

[X]

Originally Posted by Bill Thompson 75

Goals may be nutrition, environment, concealment, etc. which are sought by nearly all life forms from the microscopic to the largest.

There is only one goal: To have offspring.

Everything else is only there to help achieve that goal.



(It's really more akin to the driving force behind evolution, but I think the term "goal" fits, too.)

[Bill Thompson 75]

Originally Posted by X

There is only one goal: To have offspring.

Everything else is only there to help achieve that goal.

(It's really more akin to the driving force behind evolution, but I think the term "goal" fits, too.)

For most life forms survival goals are much more immediate than reproduction.
Mating is a goal and parenting is an instinct.
Reproduction is an evolutionary developed process that is protected by achieving the goals of survival.

[X]

Originally Posted by Bill Thompson 75

For most life forms survival goals are much more immediate than reproduction.
Mating is a goal and parenting is an instinct.
Reproduction is an evolutionary developed process that is protected by achieving the goals of survival.

Survival falls under the umbrella of reproduction.
If you don't survive long enough to reproduce, you don't reproduce. Which makes you an evolutionary failure.


Reproduction itself is not an evolutionary developed process (although the techniques used certainly are).

Reproduction is what enables evolution to happen. Offspring further your genetic material in a population. Variations occur. Most are benign, and make no difference. Some are harmful, and are weeded out. But a very few are useful, giving the individuals with those helpful changes a better chance of producing more offspring. Which in turn carry that helpful mutation, and spread it further into the population.

Without reproduction, the genes go nowhere. The species (or at least the individual's line) dies out.


Reproduction is the key to evolution.

The species that are most succesful, therefore, are not the ones that live longest, but the ones that reproduce best. You only have to live long enough to ensure your offspring survive. No longer. The numerous species that don't survive after mating or bearing young are a testament to that.

Anything else, such as a long lifespan after fertility is over, is gravy.

[Bill Thompson 75]

Originally Posted by X

Survival falls under the umbrella of reproduction.

That is saying that reproduction includes hunting, gathering, sheltering, disguising, etc. It is more appropriate to place reproduction under the umbrella of survival (family, clan, society increase the survival chances of the individual).

Originally Posted by X

If you don't survive long enough to reproduce, you don't reproduce. Which makes you an evolutionary failure.

That is why survival is the primary goal of the individual.

Originally Posted by X

Reproduction itself is not an evolutionary developed process (although the techniques used certainly are).

I'm pretty sure that the reproduction of primates has developed beyond that of the amoeba and I think evolution is the process behind it.

Originally Posted by X

Reproduction is what enables evolution to happen. Offspring further your genetic material in a population. Variations occur. Most are benign, and make no difference. Some are harmful, and are weeded out. But a very few are useful, giving the individuals with those helpful changes a better chance of producing more offspring. Which in turn carry that helpful mutation, and spread it further into the population.

Without reproduction, the genes go nowhere. The species (or at least the individual's line) dies out.

Thanks for the grade school course in evolution.

Originally Posted by X

Reproduction is the key to evolution.

The species that are most succesful, therefore, are not the ones that live longest, but the ones that reproduce best. You only have to live long enough to ensure your offspring survive. No longer. The numerous species that don't survive after mating or bearing young are a testament to that.

Anything else, such as a long lifespan after fertility is over, is gravy.

Evolution is the variation of traits and the selection of those traits by survival of the individual (and throw in some random genetic drift). Reproduction does not cause the first and only indirectly helps with the second.

Very few species mate because they have a goal of having offspring.
The goal is to satisfy the urge to mate.

[Pup]

Originally Posted by Bill Thompson 75

Quote:

Originally Posted by X
If you don't survive long enough to reproduce, you don't reproduce. Which makes you an evolutionary failure.

That is why survival is the primary goal of the individual.

I'd take it back a step further, though, and say that the reason the individual's primary goal is to survive, is because it's been bred into him by being the offspring of a long line of people who had an urge to survive, the rest having failed to live long enough to reproduce and raise their young.

It's like the old joke about a chicken just being an egg's way of making another egg.

[jimbob]

Originally Posted by Bill Thompson 75

Originally Posted by X

Survival falls under the umbrella of reproduction.

That is saying that reproduction includes hunting, gathering, sheltering, disguising, etc. It is more appropriate to place reproduction under the umbrella of survival (family, clan, society increase the survival chances of the individual).

We are not talking about any "goal" of any particular *organism*. I'd avoid the word altogether.

As Thomas Huxley said, "how stupid of me not to have thought of that". In retrospect evolution is simple, to the point that it is hard to avoid tautological statements.

If a gene doesn't reproduce it will not take part in evolution.

Natural selection selects those carriers of genes that reproduce. Variation acts on the genetic material, and selection acts on the expression of this material.

Originally Posted by Bill Thompson 75

Originally Posted by X

If you don't survive long enough to reproduce, you don't reproduce. Which makes you an evolutionary failure.

That is why survival is the primary goal of the individual.

Not in all cases.

There are whole areas of biology devoted to the genetic advantage of altruistic behaviour. For example, most honeybees do not reproduce as they are workers; the survival or death of a worker bee doesn't impact whether its genes propagate, except in as much as it impacts on the reproductive success of its sister queen or brother drones.

If dying improves the reproductive success of the genes, then there will be an evolutionary pressure towards dying in the manner most likely to boost this. For example octopodes are often considered to be some of teh most intelligent invertibrates, but in many species, the mother dies after looking after her brood, mainly because she starves to death in guarding it.


You can also look at cancers as the flip side of this, because a mutation in the DNA of a cell propagates itself at the expense of the parent organism. In fact with
Devil facial tumour disease the cancer has outlived its parent, and looks as if it might only die out with its species.

Originally Posted by Bill Thompson 75

Originally Posted by X

Reproduction itself is not an evolutionary developed process (although the techniques used certainly are).

I'm pretty sure that the reproduction of primates has developed beyond that of the amoeba and I think evolution is the process behind it.

I'd disagree.

That is just because we can notice large life.

They have been evolving for the same length of time, (from a common ancestor) but the amoeba has had tens of thousands of times as many generations to evolve in.

Originally Posted by Bill Thompson 75

Originally Posted by X

Reproduction is what enables evolution to happen. Offspring further your genetic material in a population. Variations occur. Most are benign, and make no difference. Some are harmful, and are weeded out. But a very few are useful, giving the individuals with those helpful changes a better chance of producing more offspring. Which in turn carry that helpful mutation, and spread it further into the population.

Without reproduction, the genes go nowhere. The species (or at least the individual's line) dies out.

Thanks for the grade school course in evolution.

Originally Posted by X

Reproduction is the key to evolution.

The species that are most succesful, therefore, are not the ones that live longest, but the ones that reproduce best. You only have to live long enough to ensure your offspring survive. No longer. The numerous species that don't survive after mating or bearing young are a testament to that.

Anything else, such as a long lifespan after fertility is over, is gravy.

Evolution is the variation of traits and the selection of those traits by survival of the individual (and throw in some random genetic drift). Reproduction does not cause the first and only indirectly helps with the second.

No, selection occurs on the carriers of genes, and variation occurs on the genes themselves. Evolution is driven by reproduction.

Originally Posted by Bill Thompson 75

Very few species mate because they have a goal of having offspring.
The goal is to satisfy the urge to mate.

This is back to front. Organisms have the urge to reproduce because any that didn't reproduce didn't successfully reproduce and thus took no part in evolution.

[X]

Originally Posted by Bill Thompson 75

That is saying that reproduction includes hunting, gathering, sheltering, disguising, etc. It is more appropriate to place reproduction under the umbrella of survival (family, clan, society increase the survival chances of the individual).

Yes and no, depending on how you are defining "survival".
Are you reffering to survival of an individual, or of the species?

If an individual survives long enough to reproduce, it's succeeded. If it can reproduce more than once and/or have multiple offspring, it's succeeded to an even greater degree.
If it survives, but does not reproduce, then all the good genes it has will not enter the population. And it's line will be selected against.

Originally Posted by Bill Thompson 75

That is why survival is the primary goal of the individual.

Of the individual? Yes.
Of evolution? I still think that survival long enough to reproduce is what is most important.

Again, I re-iterate: This is a loose interpretation of "goal". The term "goal" implies strategy. Evolution is merely a process, akin to a filter in my mind, but those species which reproduce better prosper. So "goal", while imprecise, is workable from that perspective.

Originally Posted by Bill Thompson 75

I'm pretty sure that the reproduction of primates has developed beyond that of the amoeba and I think evolution is the process behind it.

Which is why I said the techniques used are evolved.

Originally Posted by Bill Thompson 75

Thanks for the grade school course in evolution.

You're welcome. I figured it would be helpful to go over my thought processes on this. Just in case I'm wrong somewhere, or we turn out to be looking at the same thing from a different angle.

Originally Posted by Bill Thompson 75

Evolution is the variation of traits and the selection of those traits by survival of the individual (and throw in some random genetic drift). Reproduction does not cause the first and only indirectly helps with the second.

And here, I think, is where we differ in our approaches.
You say survival of the individual, and I would say succesful reproduction of the individual.
If the individual leads a long and healthy life, but does not reproduce (or does not reproduce very succesfully), where does evolution occur?
However, if another individual does reproduce (or reproduces more succesfully), even if it lives a shorter life, in time, that individuals genes will win out in the population.

Evolution works through reproduction, in conjunction with random variation. But you need to have reproduction.
Anything which favours reproduction will be selected for.
Anything which doesn't, will be selected against.

Originally Posted by Bill Thompson 75

Very few species mate because they have a goal of having offspring.
The goal is to satisfy the urge to mate.

I never said species mate with the goal of having offspring.
But the urge to mate results in offspring. And thus I say: If anything can be termed the "goal" of evolution, it is to have reproduce.

[Bill Thompson 75]

First, I notice that you tend to mix reproduction of a member of a species and genetic reproduction. And it almost sounds like you are equating gene evolution to species evolution.

Originally Posted by jimbob

We are not talking about any "goal" of any particular *organism*. I'd avoid the word altogether.

Well, yes we were.

Originally Posted by jimbob

As Thomas Huxley said, "how stupid of me not to have thought of that". In retrospect evolution is simple, to the point that it is hard to avoid tautological statements.

If a gene doesn't reproduce it will not take part in evolution.

Natural selection selects those carriers of genes that reproduce. Variation acts on the genetic material, and selection acts on the expression of this material.

I think this is called a tautology.

Originally Posted by jimbob

Not in all cases.

There are whole areas of biology devoted to the genetic advantage of altruistic behaviour. For example, most honeybees do not reproduce as they are workers; the survival or death of a worker bee doesn't impact whether its genes propagate, except in as much as it impacts on the reproductive success of its sister queen or brother drones.

If dying improves the reproductive success of the genes, then there will be an evolutionary pressure towards dying in the manner most likely to boost this. For example octopodes are often considered to be some of teh most intelligent invertibrates, but in many species, the mother dies after looking after her brood, mainly because she starves to death in guarding it.

You can also look at cancers as the flip side of this, because a mutation in the DNA of a cell propagates itself at the expense of the parent organism. In fact with
Devil facial tumour disease the cancer has outlived its parent, and looks as if it might only die out with its species.

It looks like you found a couple of exceptions to the millions of non-exceptions.

Originally Posted by jimbob

I'd disagree.

That is just because we can notice large life.

They have been evolving for the same length of time, (from a common ancestor) but the amoeba has had tens of thousands of times as many generations to evolve in.

So, taking humans as an example of a primate, are you saying that the biological systems of the human anatomy have not evolved or that the amoeba is a completely different organism now from what it was thousands of generations ago?

Originally Posted by jimbob

No, selection occurs on the carriers of genes, and variation occurs on the genes themselves. Evolution is driven by reproduction.

How does reproduction cause variation or selection?
Also, I checked a couple of convenient online science sites and none seem to agree with your idea that reproduction drives evolution.

Originally Posted by jimbob

This is back to front. Organisms have the urge to reproduce because any that didn't reproduce didn't successfully reproduce and thus took no part in evolution.

So, you are saying that organisms have an urge to reproduce to satisfy their urge to evolve?

[Maia]

Originally Posted by Bill Thompson 75

First, I notice that you tend to mix reproduction of a member of a species and genetic reproduction. And it almost sounds like you are equating gene evolution to species evolution.



Well, yes we were.



I think this is called a tautology.



It looks like you found a couple of exceptions to the millions of non-exceptions.



So, taking humans as an example of a primate, are you saying that the biological systems of the human anatomy have not evolved or that the amoeba is a completely different organism now from what it was thousands of generations ago?



How does reproduction cause variation or selection?
Also, I checked a couple of convenient online science sites and none seem to agree with your idea that reproduction drives evolution.



So, you are saying that organisms have an urge to reproduce to satisfy their urge to evolve?

Okay, this really needs to be split off as an entire thread, IMHO. I can see why off-topic discussions are coming up (the original arguments really don't make any sense anymore), but it just doesn't have anything to do with the original topic, either.

[jimbob]

Before this splits...

Originally Posted by Bill Thompson 75

First, I notice that you tend to mix reproduction of a member of a species and genetic reproduction. And it almost sounds like you are equating gene evolution to species evolution.

Speciation occurs as a result of evolutionary pressures, but "species" don't really evolve - the descendants of an organism evolve, and this causes the speciation.

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

Not in all cases.

There are whole areas of biology devoted to the genetic advantage of altruistic behaviour. For example, most honeybees do not reproduce as they are workers; the survival or death of a worker bee doesn't impact whether its genes propagate, except in as much as it impacts on the reproductive success of its sister queen or brother drones.

If dying improves the reproductive success of the genes, then there will be an evolutionary pressure towards dying in the manner most likely to boost this. For example octopodes are often considered to be some of teh most intelligent invertibrates, but in many species, the mother dies after looking after her brood, mainly because she starves to death in guarding it.

You can also look at cancers as the flip side of this, because a mutation in the DNA of a cell propagates itself at the expense of the parent organism. In fact with
Devil facial tumour disease the cancer has outlived its parent, and looks as if it might only die out with its species.

It looks like you found a couple of exceptions to the millions of non-exceptions.

No, I gave a couple of examples off the top of my head, without even using google.

Social insects are pretty significant, and only a small proportion of their populations are "breeders", the rest reproduce their genes by supporting their breeding siblings.

The Naked Mole rat is another interesting example in that it is the closest to a mammalian hive organism, where there is a dominant mother, and lots of offspring. One would have thought that as the non-breeding females are not actually clones, it might be a "better bet" for their gene propagation if they independently bread, but this is (obviously) not the case. Due to inbreeding, the siblings are genetically more close to each other than a naive estimate assuming that their parents were unrelated.

There has also been discussion about how the human menopause evolved, because again (at first sight) it would seem to make reproductive sense for a woman to keep breeding until death intervenes. Various reasons have been proposed, which all come down to mechanisms that would otherwise reduce the reproductive success of granddaughters.

The survival instinct has only evolved because it helps reproduction. There are many situations where it hinders reproduction, and then it is absent.

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

No, selection occurs on the carriers of genes, and variation occurs on the genes themselves. Evolution is driven by reproduction.

How does reproduction cause variation or selection?
Also, I checked a couple of convenient online science sites and none seem to agree with your idea that reproduction drives evolution.

I'd be interested in which sites.

In Darwinian Evolution but not Lamarckian, you have an initial population of organisms with some variation: these all "try" to reproduce but most will fail. Those that succeed in reproducing are by definition sufficiently well-adapted to the environment to reproduce.

Imperfect copies of these successful organisms are made (further variation is introduced). This new population then "tries" to reproduce, and again most will fail. Again, by definition, any organism that does reproduce is sufficiently well adapted to its environment. This is repeated over each generation, and variations ("traits") that increase reproductive success will evolve.



The "carriers" of the genes are the organisms. In asexual reproduction (because it is conceptually simpler), the

If you had to determine which organisms "win" at natural selection, what criteria would you use? I'd say that not leaving any descendants is "losing" in this case. (Hence the digression about altruistic behaviour). Leaving descendants involves reproduction.

Most Popes (even when they live to a ripe old age) have been evolutionary dead ends.Although I understand that this mightn't have always the case in the middle ages.

Reproduction isn't the important bit, it is no good having non-reproducing offspring, so a horse that mates with a donkey might produce offspring, but these are famously infertile.

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

This is back to front. Organisms have the urge to reproduce because any that didn't reproduce didn't successfully reproduce and thus took no part in evolution.

So, you are saying that organisms have an urge to reproduce to satisfy their urge to evolve?

No.

Organisms have an urge to reproduce because any organisms that lacked this urge would not reproduce (ignoring rape or analogues for simplicity).

Restricting the argument to mammals: Sex is enjoyable because those organisms that didn't want to mate didn't produce offspring. There is no urge to evolve, I'd guess that with most organisms (including many human parents) there is no urge to "reproduce". There is an urge to mate, which happens to lead to reproduction. In mammals, there is an urge to look after one's offspring, but that is separate to "reproduction", even though it is part of producing offspring that reproduce.


An analogy might be useful:

I am an engineer, and evolutionary algorithms are becoming more mainstream in my field. In this case you describe an initial design in parameters (genes) and then copy the design but make (pseudorandom) changes to the parameters. You then test how the implementations of the design performs against some criteria and then select the best to "breed" from.

You copy these best designs and make some further random alterations to the "genes" and repeat this process several hundred times.

The variation is in the "design" (analogue of the gene) the selection occurs in the testing of the implementation of the design (analogue of the organism).

[LashL]

As requested, several posts have been split to a new thread from this thread. If I've missed any posts that participants think should be moved here, please report them or PM me and they can be moved as well.

Posted By:LashL

[Bill Thompson 75]

Originally Posted by jimbob

Speciation occurs as a result of evolutionary pressures, but "species" don't really evolve - the descendants of an organism evolve, and this causes the speciation.

Members of a species evolve but species do not. To use your phrase, this is back to front.

Originally Posted by jimbob

The survival instinct has only evolved because it helps reproduction. There are many situations where it hinders reproduction, and then it is absent.

The survival instinct helps selection, which may or may not lead to reproduction.

Originally Posted by jimbob

I'd be interested in which sites.

http://webcache.googleusercontent.co...ient=firefox-a

http://webcache.googleusercontent.co...ient=firefox-a

Originally Posted by jimbob

If you had to determine which organisms "win" at natural selection, what criteria would you use? I'd say that not leaving any descendants is "losing" in this case. (Hence the digression about altruistic behaviour). Leaving descendants involves reproduction.

Leaving descendants is driven by variations which create winning competitors and by selection which defines the nature of the competition.

Originally Posted by jimbob

Most Popes (even when they live to a ripe old age) have been evolutionary dead ends.Although I understand that this mightn't have always the case in the middle ages.

Reproduction isn't the important bit, it is no good having non-reproducing offspring, so a horse that mates with a donkey might produce offspring, but these are famously infertile.

No.

Organisms have an urge to reproduce because any organisms that lacked this urge would not reproduce (ignoring rape or analogues for simplicity).

Restricting the argument to mammals: Sex is enjoyable because those organisms that didn't want to mate didn't produce offspring. There is no urge to evolve, I'd guess that with most organisms (including many human parents) there is no urge to "reproduce". There is an urge to mate, which happens to lead to reproduction. In mammals, there is an urge to look after one's offspring, but that is separate to "reproduction", even though it is part of producing offspring that reproduce.

Mating and reproduction are two separate things. In most mammals if there is an urge, it is to mate. Humans can completely separate the two: mating without reproduction, reproducing without mating (in vitro, surrogates, etc.).

Originally Posted by jimbob

An analogy might be useful:

I am an engineer, and evolutionary algorithms are becoming more mainstream in my field. In this case you describe an initial design in parameters (genes) and then copy the design but make (pseudorandom) changes to the parameters. You then test how the implementations of the design performs against some criteria and then select the best to "breed" from.

Good analogy.
Variation:

Originally Posted by jimbob

You copy these best designs and make some further random alterations to the "genes" and repeat this process several hundred times.

Selection:

Originally Posted by jimbob

The variation is in the "design" (analogue of the gene) the selection occurs in the testing of the implementation of the design (analogue of the organism).

[jimbob]

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

Speciation occurs as a result of evolutionary pressures, but "species" don't really evolve - the descendants of an organism evolve, and this causes the speciation.

Members of a species evolve but species do not. To use your phrase, this is back to front.

No - individuals don't evolve. Their DNA, might change due to mutagenic agents, but evolution acts on populations over generations.

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

The survival instinct has only evolved because it helps reproduction. There are many situations where it hinders reproduction, and then it is absent.

The survival instinct helps selection, which may or may not lead to reproduction.

You need to survive long enough...

Long enough for what?

Long enough to breed (and for your (fertile) offspring to become independent).

A mayfly that breeds is not an evolutionary dead end, whilst a Pope is.

Similarly, whilst Galapagos tortoises were adapted to their particular lifestyle, their individual longevity is not evidence of better adaptation than a short-lived organism (say a rabbit).

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

Originally Posted by Bill Thompson 75

How does reproduction cause variation or selection?
Also, I checked a couple of convenient online science sites and none seem to agree with your idea that reproduction drives evolution.

I'd be interested in which sites.

http://webcache.googleusercontent.co...ient=firefox-a

http://webcache.googleusercontent.co...ient=firefox-a

Paraphrasing the first site, it is saying that genetic drift is important. This is undoubtedly true. Indeed I have argued ad nauseam that this is important in other threads:

Here for example, or search my posting history evolution and probabilistic, or "fitness landscape".

A summation of my position in these threads is that there are complex feedback loops in which the fitness landscapes alter as a result of other organisms, and is probabilistic (so that some "seemingly fitter" organisms fail to breed - seemingly less fit organisms tend not to bread because the dice are loaded so strongly against reproduction anyway). The net result is that some form of adaptation is inevitable but what shape this form takes is not.

The Long term Evolution Experiment (key pdf paper here) has set out to answer this question.

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

If you had to determine which organisms "win" at natural selection, what criteria would you use? I'd say that not leaving any descendants is "losing" in this case. (Hence the digression about altruistic behaviour). Leaving descendants involves reproduction.

Leaving descendants is driven by variations which create winning competitors and by selection which defines the nature of the competition.

And how do you leave descendants?

By reproducing.

Reproduction is implicit in the process of natural selection. Indeed, I have stated elsewhere that imperfect self-replication is necessary and sufficient for evolution. The imperfections in copying provide the variation, and the attempted self-replication provides the selection, failure to replicate is an evolutionary dead end.

On a lighter note, reproduction's necessity is well accepted, even within "popular" culture:

http://www.darwinawards.com/rules/

Quote:

Rules

So how are the Darwin Awards actually determined?

Nominees significantly improve the gene pool by eliminating themselves from the human race in an obviously stupid way. They are self-selected examples of the dangers inherent in a lack of common sense, and all human races, cultures, and socioeconomic groups are eligible to compete. Actual winners must meet the following criteria:

Reproduction
Out of the gene pool: dead or sterile.
Excellence
Astounding misapplication of judgment.
Self-Selection
Cause one's own demise.
Maturity
Capable of sound judgment.
Veracity
The event must be true.

The second site is talking about another very interesting factor, which is how genes are expressed in different environments.

This is important, but I would argue that this just shows an additional layer of complexity in the template that is coded for in the genes.

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

Most Popes (even when they live to a ripe old age) have been evolutionary dead ends.Although I understand that this mightn't have always the case in the middle ages.

Reproduction isn't the important bit, it is no good having non-reproducing offspring, so a horse that mates with a donkey might produce offspring, but these are famously infertile.

No.

Organisms have an urge to reproduce because any organisms that lacked this urge would not reproduce (ignoring rape or analogues for simplicity).

Restricting the argument to mammals: Sex is enjoyable because those organisms that didn't want to mate didn't produce offspring. There is no urge to evolve, I'd guess that with most organisms (including many human parents) there is no urge to "reproduce". There is an urge to mate, which happens to lead to reproduction. In mammals, there is an urge to look after one's offspring, but that is separate to "reproduction", even though it is part of producing offspring that reproduce.

Mating and reproduction are two separate things. In most mammals if there is an urge, it is to mate. Humans can completely separate the two: mating without reproduction, reproducing without mating (in vitro, surrogates, etc.).

True, but I would argue that is immaterial (there are discussions about what the evolutionary advantages of human sexual behaviours are, especially when compared to our nearest cousins, Chimps and Bonobos).

Originally Posted by Bill Thompson 75

Originally Posted by jimbob

An analogy might be useful:

I am an engineer, and evolutionary algorithms are becoming more mainstream in my field. In this case you describe an initial design in parameters (genes) and then copy the design but make (pseudorandom) changes to the parameters. You then test how the implementations of the design performs against some criteria and then select the best to "breed" from.

Good analogy.
Variation:

Originally Posted by jimbob

You copy these best designs and make some further random alterations to the "genes" and repeat this process several hundred times.

The alteration to the design is the variation, true.

Quote:

Selection:

Originally Posted by jimbob

The variation is in the "design" (analogue of the gene) the selection occurs in the testing of the implementation of the design (analogue of the organism).

What do you do with the "selected" designs? If you just say "I have selected this" then nothing really happens, especially in the first generation.

You take the selected designs then copy them with further (pesudo)random alterations to their design. These are then tested, and the process repeats.

At the end, you "select" a design, which you might then copy as a production design.

[Dancing David]

Originally Posted by Bill Thompson 75

Goals may be nutrition, environment, concealment, etc. which are sought by nearly all life forms from the microscopic to the largest.

Hi, it was a small quibble, evolution is blind, the benefits to reproduction are unknown to the organism, evolution is blind, so that is all I meant in response to

Quote:

http://forums.randi.org/showpost.php...postcount=2623
known chemical reactions --> known chemical reactions producing electricity --> known primitive growth-oriented processes --> known evolutionary processes --> 500 million years --> known advanced goal-oriented processes --> humankind

Which one of these commonly accepted scientific concepts do you disagree with?

So I was just pointing out that evolution through reproductive success is blind to "advanced goal-oriented processes". I was not agreeing with Radrook.

ETA: I just got back from vacation, sorry I missed this.

[Dancing David]

Originally Posted by Bill Thompson 75

For most life forms survival goals are much more immediate than reproduction.
Mating is a goal and parenting is an instinct.
Reproduction is an evolutionary developed process that is protected by achieving the goals of survival.

Yes and no, which is why organisms can detroy themselves and their environment as long as they reproduce, evolution only cares about reproduction.
So cholera can kill its host as long as it reproduces.

[Dancing David]

Originally Posted by Bill Thompson 75

Evolution is the variation of traits and the selection of those traits by survival of the individual (and throw in some random genetic drift). Reproduction does not cause the first and only indirectly helps with the second.

Sorry Bill, in the ToE all that matters is reproduction , many examples exist that show that. Honeybees have non-reproductive members, because there is the one that reproduces.

Many critters breed and then die, many other critters don't care about survival of the individual at all, only that they reproduce, that is why for hundreds of thousands of some insects only a few will reproduce, for reptiles and amphibians, and a few out of hundreds. same for all organisms, it is not the survival of the individual that leads speciation but reproduction.

Why else would ebola kill its host? (becuase like cholera the mechanism that spreads the reproductive units is what kills the host.)

[Bill Thompson 75]

QUOTE=jimbob;6080374]No - individuals don't evolve. Their DNA, might change due to mutagenic agents, but evolution acts on populations over generations.[/quote]

I should have made that more clear but that was your statement that you were contradicting.

Originally Posted by jimbob

Reproduction is implicit in the process of natural selection. Indeed, I have stated elsewhere that imperfect self-replication is necessary and sufficient for evolution. The imperfections in copying provide the variation, and the attempted self-replication provides the selection, failure to replicate is an evolutionary dead end.

Nearly every member of nearly every species can reproduce. Evolution generates improvements by the elimination of the "reproductions" that do not survive.

The selection process is the key to determining which variations survive to contribute to the evolutionary process.

Reproduction is necessary to the continuation of a species. It contributes nothing more to evolution than what it already contributes to continuation.

Variation and selection are necessary to the evolution of a species beyond its mere unchanging continuation.

A species can continue through reproduction but it cannot evolve without variation and selection.

[Bill Thompson 75]

Originally Posted by Dancing David

...in the ToE all that matters is reproduction...

...it is not the survival of the individual that leads speciation but reproduction.

Reproduction is necessary to the continuation of a species. It contributes nothing more to evolution than what it already contributes to continuation.

A species can continue through reproduction but it cannot evolve without variation and selection.

[Dancing David]

Originally Posted by Bill Thompson 75

Nearly every member of nearly every species can reproduce. Evolution generates improvements by the elimination of the "reproductions" that do not survive.

Not so, the vast majority of variation is neutral, some benefit reproduction, some detriment it.

[Dancing David]

Originally Posted by Bill Thompson 75

Reproduction is necessary to the continuation of a species. It contributes nothing more to evolution than what it already contributes to continuation.

A species can continue through reproduction but it cannot evolve without variation and selection.

Quite so, I was stressing that evolution is more about the reproductive success rather than 'survival'.

[jimbob]

As Dancing David has said, the statement that 'Nearly every member of nearly every species can reproduce.' is simplistic.

If you consider population's importance by total biomass, then hive insects are huge. Only the queen (and drones) could reproduce.

A simple Malthusian treatment can show that the vast majority of individual organisms will fail to reproduce. The population will grow until it is limited by resources (including food, mates and space), predation (which could include disease), or (in humans) birth control.

Quote:

The selection process is the key to determining which variations survive to contribute to the evolutionary process.

Reproduction is necessary to the continuation of a species. It contributes nothing more to evolution than what it already contributes to continuation.

But what form does this selection take?

The "template" is in the form of DNA. Only the DNA that is within living organisms is "in play".

If this DNA is within an organism that has no chance of reproducing, then it is "out of play".

Lonesome George, is still alive, and could have another century or so of life, but he isn't breeding, so his genes are in an evolutionary dead end. In the unlikely event that he breeds, then he will have "passed the selection test".

Quote:

Variation and selection are necessary to the evolution of a species beyond its mere unchanging continuation.

A species can continue through reproduction but it cannot evolve without variation and selection.

This is back to front (see the link about Lonesome George above).

The subspecies of "Pinta Island Tortoise (Geochelone nigra abingdoni)" is currently surviving without reproduction. But it can't evolve without reproduction.

And how does the variation get introduced?

By reproduction.

In some organisms, some of the variation can come from mixing genetic material from two parents. In all organisms, there is variation due to replication errors in copying DNA*

What evolves over time is the information that is passed from generation to generation.



There is a reason why papers about evolution or evolutionary algorithms talk about "[evolutionary] generations" - it is because the selection manifests itself by selecting the information that is copied into the next generation.

Sticking to asexual organisms for simplicity:

These should all be clones of their mother, grandmother, great grandmother, and so on, for lots of generations. This isn't the case because there are mistakes in the DNA copying process (mutations). This is where the variation is introduced.

The DNA that is in the living organisms is that which is "in play". How is this passed to the next generation, with some variation? By reproduction.






*Some viruses mutate very quickly because their genetic material is carried by RNA, and despite the fact that they aren't technically alive, they do imperfectly self-replicate and do definitely evolve (rapidly).

[Bill Thompson 75]

Originally Posted by jimbob

As Dancing David has said, the statement that 'Nearly every member of nearly every species can reproduce.' is simplistic.

If you consider population's importance by total biomass, then hive insects are huge. Only the queen (and drones) could reproduce.

A simple Malthusian treatment can show that the vast majority of individual organisms will fail to reproduce. The population will grow until it is limited by resources (including food, mates and space), predation (which could include disease), or (in humans) birth control.

It looks like you found some of the exceptions I accounted for and hoped we could ignore as irrelevant.

Originally Posted by jimbob

But what form does this selection take?

The "template" is in the form of DNA. Only the DNA that is within living organisms is "in play".

If this DNA is within an organism that has no chance of reproducing, then it is "out of play".

Lonesome George, is still alive, and could have another century or so of life, but he isn't breeding, so his genes are in an evolutionary dead end. In the unlikely event that he breeds, then he will have "passed the selection test".

It seems quite irrelevant.
We already know that selection is important.

Originally Posted by Bill Thompson 75

Variation and selection are necessary to the evolution of a species beyond its mere unchanging continuation.

A species can continue through reproduction but it cannot evolve without variation and selection.

Originally Posted by jimbob

This is back to front (see the link about Lonesome George above).

Which of those two statements do you view as inaccurate?
Do you claim that variation and selection are not necessary to evolution?

Originally Posted by jimbob

The subspecies of "Pinta Island Tortoise (Geochelone nigra abingdoni)" is currently surviving without reproduction. But it can't evolve without reproduction.

You seem to be saying that reproduction is necessary to evolution. Well, if anyone disagreed with this it would be relevant.

Originally Posted by jimbob

And how does the variation get introduced?
By reproduction.

This is false. See my comment following.

Originally Posted by jimbob

In some organisms, some of the variation can come from mixing genetic material from two parents. In all organisms, there is variation due to replication errors in copying DNA*

What evolves over time is the information that is passed from generation to generation.

Variation comes from two sources: the recombination of genes from parents and mutations. Reproduction does not cause, initiate, or introduce either of these. Both variations occur in the genes whether or not an offspring is produced. Reproduction passes genes on whether there is variation or not.

Originally Posted by jimbob

There is a reason why papers about evolution or evolutionary algorithms talk about "[evolutionary] generations" - it is because the selection manifests itself by selecting the information that is copied into the next generation.

Sticking to asexual organisms for simplicity:

These should all be clones of their mother, grandmother, great grandmother, and so on, for lots of generations. This isn't the case because there are mistakes in the DNA copying process (mutations). This is where the variation is introduced.

The DNA that is in the living organisms is that which is "in play". How is this passed to the next generation, with some variation? By reproduction.

If you limited your evolutionary studies to reproduction how far do think you would get as a scientific evolutionist?

In evolution, reproduction is the vehicle but variation and selection are the drivers.

[jimbob]

Quote:

It looks like you found some of the exceptions I accounted for and hoped we could ignore as irrelevant.

How are insects irrelevant?

In biomass, termites alone tend to out-mass vertebrates within their territories.

There are more species of ants alone (about 8000) than there are mammals (about 5,500)



Barring mutagenic effects, the vast majority of genetic variation occurs during DNA replication, because it is an inherently error-prone process.

If the DNA doesn't get passed on it is in an evolutionary dead end.

I don't understand what you are proposing natural selection is, if it isn't reproduction.


Would you say that Lonseome George has been "selected"?

[Bill Thompson 75]

Originally Posted by jimbob

How are insects irrelevant?

In biomass, termites alone tend to out-mass vertebrates within their territories.

There are more species of ants alone (about 8000) than there are mammals (about 5,500)

The debate is about the importance of different features of evolution and you presented insects as a species that has features that do not advance the debate.

Originally Posted by jimbob

Barring mutagenic effects, the vast majority of genetic variation occurs during DNA replication, because it is an inherently error-prone process.

If the DNA doesn't get passed on it is in an evolutionary dead end.

I don't understand what you are proposing natural selection is, if it isn't reproduction.

Natural selection is the process for differentiating which individuals will survive healthily and long enough to engage in reproduction and which will not.

Originally Posted by jimbob

Would you say that Lonseome George has been "selected"?

Not yet.

[Dancing David]

Again billthompson75, survival is not as crucial as reproduction, a half assed organism that reproduces quickly will tend to dominate a well made one that reproduces more slowly.

You are right survival to reproduction does matter, yet reproducing matters most.

There is no 'advancement' between species, ants and other social insects are very highly evolved, as are viruses and bacteria, there is no hierarchy in progress.


Again survival of one in ten thousand~one hundred thousand insects does not matter as much as the rate at which they reproduce.

[Bill Thompson 75]

Originally Posted by Dancing David

Again billthompson75, survival is not as crucial as reproduction, a half assed organism that reproduces quickly will tend to dominate a well made one that reproduces more slowly.

You are right survival to reproduction does matter, yet reproducing matters most.

There is no 'advancement' between species, ants and other social insects are very highly evolved, as are viruses and bacteria, there is no hierarchy in progress.


Again survival of one in ten thousand~one hundred thousand insects does not matter as much as the rate at which they reproduce.

And now the topic has become survivability.

[Dancing David]

That really depends again, if only one in a hundred thousand survive and that is enough to keep the species going, well in that case reproduction matters more.

Not a very strong argument, on my part. And I can also argue that in most species, the most members do not successfully reproduce. It only takes a few that are survivng to reproduce to perpetuate the species.

[Bill Thompson 75]

Originally Posted by Dancing David

That really depends again, if only one in a hundred thousand survive and that is enough to keep the species going, well in that case reproduction matters more.

Not a very strong argument, on my part. And I can also argue that in most species, the most members do not successfully reproduce. It only takes a few that are survivng to reproduce to perpetuate the species.

You're talking about continuation, not evolution.

[X]

Evolution:
Descent with modification.


Descent. Not survival.
It's the offspring which contain the next generation of genetic changes.
Always.

No offspring -> No changes -> No evolution.

Random variation in genetic material is unavoidable.

The only thing that can be controlled is reproduction.

Does a variation help a population of the species reproduce more successfully than their rivals? It will be selected for.

Survival only matters insofar as surviving long enough to reproduce and ensure the offspring have their chance.

After that, it is in the offspring's hands (metaphorically speaking) to reproduce.

[Bill Thompson 75]

Originally Posted by X

Evolution:
Descent with modification.

Descent. Not survival.
It's the offspring which contain the next generation of genetic changes.
Always.

No offspring -> No changes -> No evolution.

Random variation in genetic material is unavoidable.

The only thing that can be controlled is reproduction.

Since, historically, evolution has not been controlled your statement clearly shows that reproduction is not the key factor in evolution.

Originally Posted by X

Does a variation help a population of the species reproduce more successfully than their rivals? It will be selected for.

You finally identified evolution: variation and selection.

Originally Posted by X

Survival only matters insofar as surviving long enough to reproduce and ensure the offspring have their chance.

This will not result in evolution.

Originally Posted by X

After that, it is in the offspring's hands (metaphorically speaking) to reproduce.

[jimbob]

Bill,

I'll go for the classic example:

How did the peacock tail evolve? It is actually an handicap and reduces the "survivability" of the peacock.

The reason is that that, due to sexual selection^WP - those peacocks with the most impressive tails tend to be more successful in mating with the peahens.

There are many social animals where the top animals have better reproductive success, many ruminants fall into this category, where a single stag will have a territory containing access to several females, and will fight other males for access to these females.

Avoiding fights would be a way of surviving longer, but a gene that increases this fight avoidance (say by reducing testosterone-linked aggression) would die out in these animals as the prospective father wouldn't get any mates. He would be likely to live longer, but "fruitlessly".

The common side blotched lizard mating strategy is very interesting in this case.

Quote:

Biologist Barry Sinervo from the University of California, Santa Cruz has discovered a rock-paper-scissors evolutionary strategy in the mating behaviour of the side-blotched lizard species Uta stansburiana. Males have either orange, blue or yellow throats and each type follows a fixed, heritable mating strategy:[1]

Orange-throated males are strongest and do not form strong pair bonds; instead, they fight blue-throated males for their females. Yellow-throated males, however, manage to snatch females away from them for mating.
Blue-throated males are middle-sized and form strong pair bonds. While they are outcompeted by orange-throated males, they can defend against yellow-throated ones.

Yellow-throated males are smallest, and their coloration mimics females. Under this disguise, they can approach orange-throated males (though not the stronger-bonding, blue-throated specimens) and mate while the orange-throats are engaged in fights.

This can be summarized as "orange beats blue, blue beats yellow, and yellow beats orange", which is similar to the rules of rock-paper-scissors.

The proportion of each male type in a population is similar in the long run, but fluctuates widely in the short term. For periods of 4–5 years, one strategy predominates, after which it declines in frequency as the strategy that manages to exploit its weakness increases. This corresponds to the stable pattern of the game in the replicator dynamics where the dynamical system follows closed orbits around the mixed strategy Nash equilibrium[citation needed] (Sinervo & Lively, 1996; Sinervo, 2001; Alonzo & Sinervo, 2001; Sinervo & Clobert, 2003; Sinervo & Zamudio, 2001).

A key insight of the Modern evolutionary synthesis^WP, is that it doesn't matter what happens to the organism, but whether the genes propagate.

These propagate by reproduction

[Bill Thompson 75]

Originally Posted by jimbob

Bill,

I'll go for the classic example:

How did the peacock tail evolve? It is actually an handicap and reduces the "survivability" of the peacock.

The reason is that that, due to sexual selection^WP - those peacocks with the most impressive tails tend to be more successful in mating with the peahens.

There are many social animals where the top animals have better reproductive success, many ruminants fall into this category, where a single stag will have a territory containing access to several females, and will fight other males for access to these females.

Avoiding fights would be a way of surviving longer, but a gene that increases this fight avoidance (say by reducing testosterone-linked aggression) would die out in these animals as the prospective father wouldn't get any mates. He would be likely to live longer, but "fruitlessly".

The common side blotched lizard mating strategy is very interesting in this case.


A key insight of the Modern evolutionary synthesis^WP, is that it doesn't matter what happens to the organism, but whether the genes propagate.

These propagate by reproduction

You presented some interesting exceptions.

You noted that propagation does not mean evolution.

And from your cited reference we have

"Natural selection is by far the main mechanism of change"

which has always been my main point.

Thank you

[jimbob]

Originally Posted by Bill Thompson 75

You presented some interesting exceptions.

You noted that propagation does not mean evolution.

And from your cited reference we have

"Natural selection is by far the main mechanism of change"

which has always been my main point.

Thank you

And how is this selection manifset?

We are saying that it is manifest by reproduction.

What are you saying.


Where did I note note that propagation doesn't mean evolution?

I stated that propagation of genes is how evolution is driven. This is what constitutes natural selection. Survival of any organism is only important in as much as it facilitates the survival of a gene.

In that natural selection is not evolution, just a vital component, I would agree that reproduction is not evolution.

Now the genes in a hypothetical immortal organism might be surviving, but if it is also sterile, there will be no more change, so there will be no more evolution of that organism's genes.

Looking at how animals age, in the context of the survival of the genes, it is counter productive for an animal to evolve a life span that is far greater than what a lucky one might live in the wild before dying. A mouse that could live to 80 if in captivity would have no selective advantage in the wild over a normal mouse that might live for 2-years in captivity, but would usually be eaten within three months. Indeed, as there will have to be metabolic effort involved in repairing the body, it would probably be at a slight selective disadvantage. Especially if it matured slightly later.

There is a lot of discussion about why humans are one of the few species where the females experience a menopause. The answer *has* to be that infertile grandmothers managed to have more grandchildren that survived compared to fertile grandmothers, where their babies would be competing with their daughters*' babies, and probably that the later-born babies tended not to survive anyway.

Having an additional child that dies young is no good for survival of one's genes. Having an additional grandchild that survives to reproduce obviously is good from this point of view. Even better would be to have an additional child that survives to breed as opposed to grandchild, as offspring share 50% of a parent's genes, whilst grandchildren only share 25% (unless the parents are cousins).


*I am talking about daughters because maternal grandmothers can be certain that their grandchildren are actually theirs. This raises another set of interesting questions that can again be answered with the approach of gene propagation.

[X]

Originally Posted by Bill Thompson 75

You finally identified evolution: variation and selection.

How does "variation" enter the equation?

(hint: it begins with "R")

What does it mean to say "selection"?

(hint: successful R_________)

@ Jimbob (and indeed, I had something similar written before trying simplicity):
To paraphrase Richard Dawkins, it is all about the Selfish Gene




Edit: Why isn't this in the Science forum?

[jimbob]

Another example:

The bonobo is the only large primate where infanticide (by males) has never been observed.

There is a perfectly simple explanation for this, and why male infanticide often does make evolutionary sense.

A newly dominant male lion will kill lion cubs. This doesn't improve the survival prospects of the male lion, in fact there must be a finite risk associated with this course of action.

However the lioness will be nurturing cubs which are not the newly dominant lion's. If her cubs die and she stops suckling, then she will become fertile again, so the newly dominant lion that practices infanticide will have more offspring.

Similarly with chimpanzees and gorillas. Why not bonobos?

These are very promiscuous animals, the females will mate with all the males (and have frequent recreational or bonding sex) with each other, as will the males. The only sexual activity that hasn't been observed is Mother-Son, which again makes sense from an evolutionary perspective, as that is about the only relationship with a guaranteed high level of inbreeding and a chance of conception.

Because of the sexual activity, any bonobo male who kills any infants is likely to be killing his own offspring.

These observations would make no sense if "survival of the organism" was the driving factor in evolution, but make perfect sense in the context of gene survival, which requires reproduction.

[Bill Thompson 75]

Originally Posted by jimbob

And how is this selection manifset?
We are saying that it is manifest by reproduction.
What are you saying.

Same thing, reproduction is necessary for selection, regardless of variation.

Originally Posted by jimbob

Where did I note note that propagation doesn't mean evolution?

You said "it doesn't matter what happens to the organism, but whether the genes propagate" without any reference to variation.

Originally Posted by jimbob

I stated that propagation of genes is how evolution is driven.

Your reference clearly said otherwise.

Originally Posted by jimbob

This is what constitutes natural selection. Survival of any organism is only important in as much as it facilitates the survival of a gene.

This is continuation, not evolution.

[Bill Thompson 75]

Originally Posted by X

How does "variation" enter the equation?

(hint: it begins with "R")

What does it mean to say "selection"?

(hint: successful R_________)

How can you distinguish between continuation and evolution without variation and selection?

(hint: you can't)

Originally Posted by X

Edit: Why isn't this in the Science forum?

No clue.

[X]

Do me a favour:

Define continuation and evolution.

I have a feeling I'm defining one of them differently than you...

[Bill Thompson 75]

Originally Posted by X

Do me a favour:

Define continuation and evolution.

I have a feeling I'm defining one of them differently than you...

I use continuation for successive generations without necessarily any factors of variation or selection involved.

I use evolution for successive generations with the factors of variation and selection involved.