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More offspring? So what?


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From time to time we see assertions that mutations and 'natural selection' result in some lifeforms having more offspring than others. And they just stop right there, like that means something.

 

I think several questions remain to be answered, but I suppose I should give some examples first.

 

http://evolution.berkeley.edu/evosite/evo101/IIIE2Fitness.shtml

These strategies do, however, increase fitness because they help the parents get more of their offspring into the next generation.

 

http://en.wikipedia.org/wiki/User:Silence/Introduction_to_evolution

Evolution occurs in two different ways. The first way is random — when a population's traits change by chance. The second way is called selection. Selection happens when a trait helps an organism to have more offspring, such as by keeping the organism from dying early. This helpful trait will tend to become more common in the population, because organisms with the trait produce more offspring — who may inherit the same trait.

 

http://www.pbs.org/wgbh/evolution/library/faq/cat01.html

In the process of natural selection, individuals in a population who are well-adapted to a particular set of environmental conditions have an advantage over those who are not so well adapted. The advantage comes in the form of survival and reproductive success. For example, those individuals who are better able to find and use a food resource will, on average, live longer and produce more offspring than those who are less successful at finding food. Inherited traits that increase individuals' fitness are then passed to their offspring, thus giving the offspring the same advantages.

 

Darwin didn't think it sufficient to "produce more offspring". In his chapter on "Struggle for Existence" (Link) he says

"Struggle for Existence" (Link)

The only difference between organisms which annually produce eggs or seeds by the thousand, and those which produce extremely few, is, that the slow breeders would require a few more years to people, under favourable conditions, a whole district, let it be ever so large.

 

He proceeds to discuss the various checks to population then in the next chapter we find

To sum up, as far as the extreme intricacy of the subject permits, the circumstances favourable and unfavourable for the production of new species through natural selection. I conclude that for terrestrial productions a large continental area, which has undergone many oscillations of level, will have been the most favourable for the production of many new forms of life, fitted to endure for a long time and to spread widely. While the area existed as a continent the inhabitants will have been numerous in individuals and kinds, and will have been subjected to severe competition. When converted by subsidence into large separate islands there will still have existed many individuals of the same species on each island: intercrossing on the confines of the range of each new species will have been checked: after physical changes of any kind immigration will have been prevented, so that new places in the polity of each island will have had to be filled up by the modification of the old inhabitants; and time will have been allowed for the varieties in each to become well modified and perfected. When, by renewed elevation, the islands were reconverted into a continental area, there will again have been very severe competition; the most favoured or improved varieties will have been enabled to spread; there will have been much extinction of the less improved forms, and the relative proportional numbers of the various inhabitants of the reunited continent will again have been changed; and again there will have been a fair field for natural selection to improve still further the inhabitants, and thus to produce new species.

This almost sounds like a prediction. Notice the emphasis on competition (death of the unfit).

 

He goes on to say

EXTINCTION CAUSED BY NATURAL SELECTION.

 

This subject will be more fully discussed in our chapter on Geology; but it must here be alluded to from being intimately connected with natural selection. Natural selection acts solely through the preservation of variations in some way advantageous, which consequently endure. Owing to the high geometrical rate of increase of all organic beings, each area is already fully stocked with inhabitants, and it follows from this, that as the favoured forms increase in number, so, generally, will the less favoured decrease and become rare. Rarity, as geology tells us, is the precursor to extinction. We can see that any form which is represented by few individuals will run a good chance of utter extinction, during great fluctuations in the nature or the seasons, or from a temporary increase in the number of its enemies. But we may go further than this; for as new forms are produced, unless we admit that specific forms can go on indefinitely increasing in number, many old forms must become extinct. That the number of specific forms has not indefinitely increased, geology plainly tells us; and we shall presently attempt to show why it is that the number of species throughout the world has not become immeasurably great.

 

We have seen that the species which are most numerous in individuals have the best chance of producing favourable variations within any given period. We have evidence of this, in the facts stated in the second chapter, showing that it is the common and diffused or dominant species which offer the greatest number of recorded varieties. Hence, rare species will be less quickly modified or improved within any given period; they will consequently be beaten in the race for life by the modified and improved descendants of the commoner species.

 

>From these several considerations I think it inevitably follows, that as new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct. The forms which stand in closest competition with those undergoing modification and improvement, will naturally suffer most. And we have seen in the chapter on the Struggle for Existence that it is the most closely-allied forms,--varieties of the same species, and species of the same genus or related genera,--which, from having nearly the same structure, constitution and habits, generally come into the severest competition with each other. Consequently, each new variety or species, during the progress of its formation, will generally press hardest on its nearest kindred, and tend to exterminate them. We see the same process of extermination among our domesticated productions, through the selection of improved forms by man. Many curious instances could be given showing how quickly new breeds of cattle, sheep and other animals, and varieties of flowers, take the place of older and inferior kinds. In Yorkshire, it is historically known that the ancient black cattle were displaced by the long-horns, and that these "were swept away by the short-horns" (I quote the words of an agricultural writer) "as if by some murderous pestilence."

Which sounds like there's an advantage to be had in numbers. But he knew nothing of genetics, which render this reasoning hollow.

 

Say A has more offspring than B. Let time pass. Before too long, the offspring of A mate with the offspring of B. The generations that follow are the offspring of both A and B. The dichotomy has vanished. Now that I think of it; you really don't need to know a lot about genetics to figure this out. Oh well...

 

Whether it be double-talk, or he simply couldn't remember what he just said, later in the same chapter he says

But during the process of modification, represented in the diagram, another of our principles, namely that of extinction, will have played an important part. As in each fully stocked country natural selection necessarily acts by the selected form having some advantage in the struggle for life over other forms, there will be a constant tendency in the improved descendants of any one species to supplant and exterminate in each stage of descent their predecessors and their original progenitor. For it should be remembered that the competition will generally be most severe between those forms which are most nearly related to each other in habits, constitution and structure. Hence all the intermediate forms between the earlier and later states, that is between the less and more improved states of a the same species, as well as the original parent-species itself, will generally tend to become extinct. So it probably will be with many whole collateral lines of descent, which will be conquered by later and improved lines. If, however, the modified offspring of a species get into some distinct country, or become quickly adapted to some quite new station, in which offspring and progenitor do not come into competition, both may continue to exist.

Now here we see that extermination of one's inferior kinsmen is what Darwin's evolution is all about. Having more offspring won't do. This is more clear when one accounts for genetics, and the spread of mutation; but on other occasions Darwin did stress the importance of eliminating the "less fit". 'Selection' is just an euphemism for death, after all. I think this post is getting long enough.

 

My first question seems to me to stand right out, but I want to be clear:

What difference does it really make if A has more offspring than B? This is just shortsightedness in action. Unless B's offspring are quickly selected, it will only be a few generations until A's offspring are B's offspring.

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From time to time we see assertions that mutations and 'natural selection' result in some lifeforms having more offspring than others. And they just stop right there, like that means something.

That's because - despite the current culture - the sort of people talking about such things with any semblance of confidence are used to having an educated audience. They'll eventually learn and continue the paragraph.

 

Darwin didn't have an understanding of genetics, no. But more importantly he didn't have an understanding of the numerics of evolutionary ecology, or of game theory, or of complex population dynamics and the equilibrium models.

 

The evolutionary sciences have moved on considerably since the Beagle so don't put too much stock in Darwin's musings. Pivotal breakthrough yes, comprehensive description no.

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Here's the short answer. Your challenge is all based on a strawman. It's not about number of offspring alone. It's about the various approaches which lead to the successful passage of genes to future generations. Sometimes organisms will be successful with few offspring, and other times organisms will be successful only with many offspring. It truly is that simple.

 

As a general rule, however, those with more offspring have a higher probability of propagating their genes into the future. The measure of success you cite is merely about "genetic representation" in the future. If organisms can successfully achieve a higher incidence of genetic representation by having fewer offspring, then that is what will generally be selected for. There is no "one right way."

 

There's really no need for claims of double talk and charges of hollow reasoning. You're just arguing a strawman like all of the worthless pile of shit creationist trolls which have come before you.

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I would second your response, iNow, but then I think I would be accused of somehow knowing the topic of this thread in advance, and collaborating with you and toasty on how to mock it...

What the hell, I'll do it anyways.

 

Read iNow's and Sayanora's post, CTD. They answer you definitively.

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That's because - despite the current culture - the sort of people talking about such things with any semblance of confidence are used to having an educated audience. They'll eventually learn and continue the paragraph.

 

Darwin didn't have an understanding of genetics, no. But more importantly he didn't have an understanding of the numerics of evolutionary ecology, or of game theory, or of complex population dynamics and the equilibrium models.

 

The evolutionary sciences have moved on considerably since the Beagle so don't put too much stock in Darwin's musings. Pivotal breakthrough yes, comprehensive description no.

Fear not - I never put much stock in Darwin's musings.

 

Perhaps one of the "educated" types you spoke about will be able to explain the significance to both of us.

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Here's the short answer. Your challenge is all based on a strawman.
If all you can do is spout false accusations, I may be soon research a bit and see if there's an ignore function available here.

 

It's not about number of offspring alone.
So any author who just ends his saga with "...and they have more offspring" is doing a disservice.

 

It's about the various approaches which lead to the successful passage of genes to future generations. Sometimes organisms will be successful with few offspring, and other times organisms will be successful only with many offspring. It truly is that simple.
And just for kicks, what is the noun to which your pronoun 'it' has been referring? 'It' is not my question; 'it' is not an answer to my question.

 

As a general rule, however, those with more offspring have a higher probability of propagating their genes into the future.
Higher than whom? And howso? Assertions are a dime a dozen (actually cheaper than that locally).

 

The measure of success you cite is merely about "genetic representation" in the future. If organisms can successfully achieve a higher incidence of genetic representation by having fewer offspring, then that is what will generally be selected for. There is no "one right way."

 

There's really no need for claims of double talk and charges of hollow reasoning. You're just arguing a strawman like all of the worthless pile of shit creationist trolls which have come before you.

What a surprise: yet another unsupportable assertion contrary to universal observation.


Merged post follows:

Consecutive posts merged

Just a quick salute to those who take the time to even read my post before slinging mud.

 

SaaaaaaLUTE !

 

P.S.

This is funnier even than I expected.

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My first question seems to me to stand right out, but I want to be clear:

What difference does it really make if A has more offspring than B? This is just shortsightedness in action. Unless B's offspring are quickly selected, it will only be a few generations until A's offspring are B's offspring.

 

Yes, and perhaps eventually every living member of the species will be descended from both A and B. That's certainly possible. But you're stuck on a dichotomy of descended/not descended, when it's really about a mixture of traits in different proportions. That future population will be substantially more A than B, even though both are direct ancestors for everyone, especially if A's offpsring tend to have more offpsring than B's as a result of the traits A and B passed on. And the mixing (and subsequent mutations) let the individual traits dominate, rather than just proportions of A's and B's genomes.

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I just liked it because it reminded me of your avatar. :) Also, I reported the troll when he first arrived. No offense, but y'all could have acted a bit more swiftly and this wouldn't have been an issue.

 

All the same, I take your point about just ignoring him.

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Higher than whom?

 

Contemporary members of its species, that don't possess the same genes.

 

And howso?

 

By having those subsequent generations in turn using those passed on traits to improve their chances of having more successful offspring, and so on. Traits that help chances are passed on more often, and so propagate. Traits that hurt chances are passed on less often, and so are minimized. Is that clear enough?

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