Does Common Descent Follow Logically From Darwin's Four Postulates?

Eugene Shubert

Valued Senior Member
As described by Scott Freeman and Jon C. Herron (2004), Evolutionary Analysis 4th Edition, Darwin's theory rests on four postulates:
The postulates, which apply to populations of organisms, are as follows:
  1. Individuals within populations are variable.
  2. The variations among individuals are, at least in part, passed from parents to offspring.
  3. In every generation, some individuals are more successful at surviving and reproducing than others.
  4. The survival and reproduction of individuals are not random; instead they are tied to the variation among individuals. The individuals with the most favorable variations, those who are better at surviving and reproducing, are naturally selected.
If these four postulates are true, then the composition of the population changes from one generation to the next. The logic is clear: If there are differences among the individuals in a population that can be passed on to offspring, and if there is differential success among those individuals in surviving and/or reproducing, then some traits will be passed on more frequently than others. As a result, the characteristics of the population will change slightly with each succeeding generation. This is Darwinian evolution: gradual change in populations over time. (Freeman and Herron (2004) Evolutionary Analysis pp. 72-73).
Does common descent follow logically from Darwin's four postulates or is common descent a logically independent fifth postulate?
 
As described by Scott Freeman and Jon C. Herron (2004), Evolutionary Analysis 4th Edition, Darwin's theory rests on four postulates:

Does common descent follow logically from Darwin's four postulates or is common descent a logically independent fifth postulate?
I don't think common descent does logically follow from these alone, no. One could envisage a world in which several strands of life arose in parallel, and then evolution could have operated on each strand independently. Perhaps in fact it did arise several times, independently. I don't think we know one way or the other.

However, evolutionary biology is natural science, not an exercise in mathematics or logic. Consequently, as in all science, the theory rests on observation, combined with reasoning, rather than on logical deductions from postulates alone.

The evidence suggests that the life we see now and which is shown in fossils seems to have arisen from one source, due to such observational evidence as the kinships between fossils, common biochemistry, DNA relationships between organisms, and so on, all of which broadly corroborate one another. In this way the various phylogenetic trees have been prepared, subject though they are to constant re-evaluation and refinement in the light of new evidence. Certain details are however beyond serious dispute, though, e.g. that mankind is descended from - and is a member of - the family of apes.

......But you know all this Eugene, of course. So now that I have replied, we confidently await some ridiculous rhetorical argument in favour of creationism :rolleyes:. I suppose for you it makes a break from feuding with various 7th Day Adventist churches in Texas, or whatever. I merely reply so that any other readers don't get the idea that this forum accepts creationist nonsense without challenge.
 
Does common descent follow logically from Darwin's four postulates or is common descent a logically independent fifth postulate?
Common descent is compatible with Darwin's four postulates. That does not mean that multiple abiogenesis events would NOT be compatible, though - Darwin's theories work for life no matter how it comes about.
 
I don't think common descent does logically follow from these alone, no.
You have answered correctly. Furthermore, since Darwin’s four postulates are thought to represent a scientific theory, then adjoining Darwin’s four postulates to the negation of the common descent postulate also constitutes a scientific theory.
One could envisage a world in which several strands of life arose in parallel, and then evolution could have operated on each strand independently.
For those who understand quantum physics, it’s also possible to imagine the fantastically improbable, virtually instantaneous quantum creation of many varieties of life all sharing a similar design structure.
However, evolutionary biology is natural science, not an exercise in mathematics or logic. Consequently, as in all science, the theory rests on observation, combined with reasoning, rather than on logical deductions from postulates alone.
I’d like to read about the foundational observations and unquestionable reasoning. Is it producible, well-documented evidence? And what is producible evidence? Is it a really good-sounding just-so story that is easily repeated and believed or something so persuasive and so clear that it makes the mightiest religionists squirm, furious or flustered? Where, for example, as a defense of popular claims, is the observation, combined with reasoning, that demonstrates that you have an ancestor whose descendants eventually evolved into plain, ordinary bananas?
 
You have answered correctly. Furthermore, since Darwin’s four postulates are thought to represent a scientific theory, then adjoining Darwin’s four postulates to the negation of the common descent postulate also constitutes a scientific theory.

For those who understand quantum physics, it’s also possible to imagine the fantastically improbable, virtually instantaneous quantum creation of many varieties of life all sharing a similar design structure.

I’d like to read about the foundational observations and unquestionable reasoning. Is it producible, well-documented evidence? And what is producible evidence? Is it a really good-sounding just-so story that is easily repeated and believed or something so persuasive and so clear that it makes the mightiest religionists squirm, furious or flustered? Where, for example, as a defense of popular claims, is the observation, combined with reasoning, that demonstrates that you have an ancestor whose descendants eventually evolved into plain, ordinary bananas?
No, Darwin's postulates do not constitute the theory, for the reasons I have explained.

And you are lying when you say you'd like to read about any of this. You could have read it years ago or on-line any time.

Anyway I am a "religionist", (though not a mighty one), and, like most of us "religionists", I have no problem whatsoever with evolution or any other theory of science. But I suppose if I were a 7th Day Adventist, or a member of another, equivalently bizarre, American protestant sect, then I might have trouble with it. Most of us, you see, do not pretend that the bible can be taken literally. Even Saint Augustine of Hippo* saw the problems with doing that in about 400 AD. It took the 7th Day Adventists, in the c.20th, to forget that common sense and usher in a new era of unparallelled idiocy in biblical misunderstanding.

Your problem is not science, which is something you have neither understanding of, nor interest in understanding. Your problem is your miserably impoverished interpretation of the Christian faith. So I don't propose to indulge you by arguing for things in science, the basis for which is understood by every schoolchild.

P.S. This Wikipaedia entry notwithstanding: https://en.wikipedia.org/wiki/Talk:Seventh-day_Adventist_Church/Graham_Maxwell , the only Maxwell I am interested in is James Clerk Maxwell. I don't suppose you have even heard of him.

* The patron saint of brewers, so he must have been a good chap and had his head screwed on.
 
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No, Darwin's postulates do not constitute the theory
I stand corrected. Darwin’s four postulates are thought to represent a scientific theory; consequently, adjoining Darwin’s four postulates to the negation of the common descent postulate should only be taken as representing a debatable scientific theory, unless you can prove by logical reasoning or otherwise demonstrate conclusively that you have an ancestor whose descendants eventually evolved into bananas.
Anyway I am a "religionist", … Your problem is your miserably impoverished interpretation of the Christian faith. So I don't propose to indulge you by arguing for things in science, the basis for which is understood by every schoolchild.
I believe that Seventh-day Millerites, circa 2017, have a very powerful understanding of the Christian faith. http://everythingimportant.org/God

Furthermore, I agree with your claim of being very religious. I also believe that you have lost this debate royally since (I think it’s clear) most sentient beings are honest enough to overwhelmingly agree that no schoolchild can present a compelling argument to prove that they have an ancestor whose descendants eventually evolved into bananas.
 
(I think it’s clear) most sentient beings are honest enough to overwhelmingly agree that no schoolchild can present a compelling argument to prove that they have an ancestor whose descendants eventually evolved into bananas.
Indisputably, if there was an easily understandable argument proving that human ancestor to yellow banana evolution occurred, it would be so laughable that it would be quoted by everyone. Where is it?
 
Furthermore, since Darwin’s four postulates are thought to represent a scientific theory, then adjoining Darwin’s four postulates to the negation of the common descent postulate also constitutes a scientific theory.
No, that doesn't follow.
Scientific theory requires agreement with physical evidence, a much more restrictive condition than mere logical consistency.
 
No, that doesn't follow.
Scientific theory requires agreement with physical evidence, a much more restrictive condition than mere logical consistency.
I corrected my poor wording in post #7.

I quote:

"Darwin’s four postulates are thought to represent a scientific theory; consequently, adjoining Darwin’s four postulates to the negation of the common descent postulate should only be taken as representing a debatable scientific theory, unless you can prove by logical reasoning or otherwise demonstrate conclusively that you have an ancestor whose descendants eventually evolved into bananas."
 
For those who understand quantum physics, it’s also possible to imagine the fantastically improbable, virtually instantaneous quantum creation of many varieties of life all sharing a similar design structure.
No. "Quantum creation" would have no bias towards any specific biological structure, since quantum mechanics is not biased towards specific biology.

You could, of course, claim that spontaneous random creation was happening all the time, and that just happens to create different kinds of life. However, if functional life could be spontaneously created by such a mechanism, we would see innumerable less-complex spontaneous creations all the time. We do not.

Where, for example, as a defense of popular claims, is the observation, combined with reasoning, that demonstrates that you have an ancestor whose descendants eventually evolved into plain, ordinary bananas?
The observation is that we share the same basic DNA structure and many of the same DNA sequences. Further observation of molecular clocks allow us to assign a rough time to the point at which our ancestors split into the Opisthokonta (later leading to man) and the Primoplantae (later leading to bananas) kingdoms. (Alternatively Plantae and Animalia; choose your favorite taxonomy.)

Further observations reveal a great many organisms that share characteristics of both kingdoms (like euglena, which exhibits both chorophyll-based food synthesis and self-propulsion via flagella.)
 
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No. "Quantum creation" would have no bias towards any specific biological structure, since quantum mechanics is not biased towards specific biology.

You could, of course, claim that spontaneous random creation was happening all the time, and that just happens to create different kinds of life. However, if functional life could be spontaneously created by such a mechanism, we would see innumerable less-complex spontaneous creations all the time. We do not.
I'm not claiming that the fantastically improbable would have a bias for the creation of life. And I obviously assert that a spontaneous random creation must be extraordinarily rare, given that the spontaneous creation of extraordinarily complex living structures must be fantastically improbable.
 
The observation is that we share the same basic DNA structure and many of the same DNA sequences.
That's not a respectable argument to prove you have an ancestor whose descendants eventually evolved into yellow bananas. Furthermore, fundamentalist creationists have no problem believing in a God that used a common design strategy for the creation of all the various forms of life on earth. And as a quantum creationist, I'm very happy to admit that the spontaneous creation of a vast array of extraordinarily complex living things having similar design structures is logically admissible, albeit fantastically improbable.
 
That's not a respectable argument to prove you have an ancestor whose descendants eventually evolved into yellow bananas
Yes, it is.

And besides, it's irrelevant - your claim that negating that fifth postulate produces a scientific theory needs physical evidence of its own, not complaints about other theories.
 
You still have to deal with the requirement that a scientific theory must agree with physical evidence.
All the physical evidence summarized in Darwin's four postulates haven't disappeared with the observation that there is no credible argument proving the human ancestor to yellow banana conjecture.
 
Your claim that negating that fifth postulate produces a scientific theory needs physical evidence of its own
In all fairness, if Darwin's four postulates adjoined with the unprovable common descent postulate represents a scientific theory, then Darwin's four postulates adjoined with the negation of the unprovable common descent postulate also represents a scientific theory.
 
All the physical evidence summarized in Darwin's four postulates haven't disappeared with the observation that there is no credible argument proving the human ancestor to yellow banana conjecture.
But there is plenty of evidence, very persuasive and uncontradicted mountains of it. And the argument is sound.
In all fairness, if Darwin's four postulates adjoined with the unprovable common descent postulate represents a scientific theory, then Darwin's four postulates adjoined with the negation of the unprovable common descent postulate also represents a scientific theory.
That is false. You would need to formulate the theory itself, in accordance with those "postulates"(dozens are possible, none currently exists afaik). Then you would need physical evidence supporting sound argument in agreement with it, as you have for the current Darwinian theory.
 
But there is plenty of evidence, very persuasive and uncontradicted mountains of it. And the argument is sound.
I'm still waiting for a link to the compelling schoolchild proof of the human ancestor to yellow banana conjecture but will enthusiastically accept your easily understandable middle or high school version of the argument.
 
Is there any person free in the general population who seriously believes yellow bananas have a human ancestor?

If you know of any such person please try to get them medical help

Act now before the slip any further to believing bees descended from whales

:)
 
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