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Old 10th June 2017, 08:53 AM   #1
Paul2
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Fossil breaks the nested hierarchy?

I'm talking with an Intelligent Design advocate who linked me to an article claiming that the nested hierarchy (morphological, I guess) has fatal problems in it -- for instance, the "flat face" of Sahelanthropus tchadensis and Diania, an early arthropod or ancestor thereof.

I can imagine several responses, I wonder which apply:

1. A few organisms that don't fit into the hierarchy doesn't cause the entire edifice to crumble. But wouldn't it merely take one or a few outliers to falsify the nested hierarchy as a predictive model in evolution? Or not?

2. These organisms don't cause a problem for the hierarchy because their place in the hierarchy is still being debated.

3. These organisms fit into the nested hierarchy without any problems.

Comments?
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Old 10th June 2017, 09:05 AM   #2
Red Baron Farms
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Originally Posted by Paul2 View Post
I'm talking with an Intelligent Design advocate who linked me to an article claiming that the nested hierarchy (morphological, I guess) has fatal problems in it -- for instance, the "flat face" of Sahelanthropus tchadensis and Diania, an early arthropod or ancestor thereof.

I can imagine several responses, I wonder which apply:

1. A few organisms that don't fit into the hierarchy doesn't cause the entire edifice to crumble. But wouldn't it merely take one or a few outliers to falsify the nested hierarchy as a predictive model in evolution? Or not?

2. These organisms don't cause a problem for the hierarchy because their place in the hierarchy is still being debated.

3. These organisms fit into the nested hierarchy without any problems.

Comments?
I pick #3
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Old 10th June 2017, 09:29 AM   #3
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I don't see much to dispute in the article, except the conclusion.
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Old 11th June 2017, 03:54 AM   #4
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Originally Posted by Red Baron Farms View Post
I pick #3
And #2 as well.
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Old 11th June 2017, 05:31 AM   #5
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This is all rather like saying the poor performance of 2-3 stocks negates the entire stock exchange concept. And keep in mind that "hierarchy" is a human abstraction derived from observation, not any sort of binding requirement laid down "from above" as it were.
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Old 11th June 2017, 05:52 AM   #6
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Originally Posted by Peregrinus View Post
This is all rather like saying the poor performance of 2-3 stocks negates the entire stock exchange concept. And keep in mind that "hierarchy" is a human abstraction derived from observation, not any sort of binding requirement laid down "from above" as it were.
Not really. Every species descends from some other. If some species doesn't fit within the nested hierarchy then there is a real problem.

Of course that doesn't have to be true of morphology, it has to be true of descent. Generally we can use morphology to give us clues about descent, but it's not always clear or easy, which is why I suggested that reasons #2 and #3 in the OP are valid.
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Old 11th June 2017, 06:00 PM   #7
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#2. The full scope of human evolution is not a completed study. One of my professors who was teaching a class in a huge hall (the size of an old style movie threatre) walked over to one of the vast walls and put a dot on it with a pencil. He said the wall space around was the number of the ancestors of humans and the dot was the amount of material we had recovered....
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Old 12th June 2017, 07:21 AM   #8
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My take:

There are a couple things to take issue with here. The first is the claim that “Together, these authorities make a crucial point: cladistics and other phylogenetics methods do not demonstrate common ancestry; they assume it.”

The reason why we use science is that it makes useful predictions. These predictions server as tests for the original theory. The fact that we can use phylogenetic methods to explain the history of life is exactly why we use them. There is no contradiction here.

The more specific issue of Sahelanthropus tchadensis having a “flat face”. Its face is currently understood by only a single distorted skull but it isn’t considered to have a face anything like our own. Even if it did this is a trait that may have evolved many times for many different reasons, not necessarily one that evolved in Sahelanthropus and remained with hominids ever after.

To the larger point Sahelanthropus fits rather easily into a phylogenetic model. If there were an organism that clearly cannot be fit into these models, then it would present a now challenge (and fantastic new opportunity!) for science but this isn’t it.
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Old 12th June 2017, 08:15 AM   #9
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Two comments here:

(1) The article seems to be presenting convergent evolution as a guilty secret or a flimsy fudge. Rationally, though, why should convergent evolution be viewed with such suspicion? All it claims, really, is that similar environmental pressures result in similar traits, hardly an earth-shattering suggestion.

(2) If there are fossils that don't fit neatly into a well-defined pattern of classifications, does this actually support intelligent design? I would say it's far closer to what would be expected from random variations in a population subject to varying pressures of natural selection, which through its fundamentally uncontrolled nature would be expected from time to time to throw up some rather unexpected results. If, on the other hand, everything fitted perfectly into a simple structure, that might point to intelligent design.

In that respect, it's a fairly well masked example of the pseudoscientific fallacy that everything that appears to conflict with the conventional theoretical framework must therefore support the presenter's preferred fiction. It's a form of the non sequitur that appears to have the structure:

P1: If statement A is true, then statement B is true.
P2: Statement A is not true (or, in the weakest form, statement A is sometimes disputed).
C: Therefore, statement C is true.

Does anyone know of a name for that specific fallacy? If not, I may have to invent one.

Dave
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Old 12th June 2017, 08:50 AM   #10
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Originally Posted by Dave Rogers View Post
Two comments here:

(1) The article seems to be presenting convergent evolution as a guilty secret or a flimsy fudge. Rationally, though, why should convergent evolution be viewed with such suspicion? All it claims, really, is that similar environmental pressures result in similar traits, hardly an earth-shattering suggestion.

(2) If there are fossils that don't fit neatly into a well-defined pattern of classifications, does this actually support intelligent design? I would say it's far closer to what would be expected from random variations in a population subject to varying pressures of natural selection, which through its fundamentally uncontrolled nature would be expected from time to time to throw up some rather unexpected results. If, on the other hand, everything fitted perfectly into a simple structure, that might point to intelligent design.

In that respect, it's a fairly well masked example of the pseudoscientific fallacy that everything that appears to conflict with the conventional theoretical framework must therefore support the presenter's preferred fiction. It's a form of the non sequitur that appears to have the structure:

P1: If statement A is true, then statement B is true.
P2: Statement A is not true (or, in the weakest form, statement A is sometimes disputed).
C: Therefore, statement C is true.

Does anyone know of a name for that specific fallacy? If not, I may have to invent one.

Dave
Non sequitur
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Old 12th June 2017, 09:01 AM   #11
Dave Rogers
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Originally Posted by Hevneren View Post
Non sequitur
Well, yes, all formal logical fallacies are. But there's a taxonomy of subsets of the set of non sequiturs, and this seems to be a frequently occurring variant.

Dave
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Tony Szamboti: That is right
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Old 12th June 2017, 09:33 AM   #12
Red Baron Farms
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Originally Posted by Dave Rogers View Post
Two comments here:

(1) The article seems to be presenting convergent evolution as a guilty secret or a flimsy fudge. Rationally, though, why should convergent evolution be viewed with such suspicion? All it claims, really, is that similar environmental pressures result in similar traits, hardly an earth-shattering suggestion.

(2) If there are fossils that don't fit neatly into a well-defined pattern of classifications, does this actually support intelligent design? I would say it's far closer to what would be expected from random variations in a population subject to varying pressures of natural selection, which through its fundamentally uncontrolled nature would be expected from time to time to throw up some rather unexpected results. If, on the other hand, everything fitted perfectly into a simple structure, that might point to intelligent design.

In that respect, it's a fairly well masked example of the pseudoscientific fallacy that everything that appears to conflict with the conventional theoretical framework must therefore support the presenter's preferred fiction. It's a form of the non sequitur that appears to have the structure:

P1: If statement A is true, then statement B is true.
P2: Statement A is not true (or, in the weakest form, statement A is sometimes disputed).
C: Therefore, statement C is true.

Does anyone know of a name for that specific fallacy? If not, I may have to invent one.

Dave
Affirmative conclusion from a negative premise (illicit negative)
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Old 12th June 2017, 09:38 AM   #13
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Originally Posted by Dave Rogers View Post
Two comments here:

(2) If there are fossils that don't fit neatly into a well-defined pattern of classifications, does this actually support intelligent design? I would say it's far closer to what would be expected from random variations in a population subject to varying pressures of natural selection, which through its fundamentally uncontrolled nature would be expected from time to time to throw up some rather unexpected results. If, on the other hand, everything fitted perfectly into a simple structure, that might point to intelligent design.
Not quite, in my opinion (but I'm not an expert). What I've read of the nested hierarchy is that it is predicted by a historical, genealogical process, whereas intelligent design is not restricted to designing by modifying last year's model, so that organisms that don't fall into the nested hierarchy (a crocoduck, for instance), would be predictive of intelligent design. The nested hierarchy needs to be consistent (=perfect or nearly so) so that we don't see crocoducks.

It's not so much a well-defined pattern of classification, but something that could not occur if the nested hierarchy reflects a historical, genealogical process.
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Old 14th June 2017, 07:37 AM   #14
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Originally Posted by Paul2 View Post
Not quite, in my opinion (but I'm not an expert). What I've read of the nested hierarchy is that it is predicted by a historical, genealogical process, whereas intelligent design is not restricted to designing by modifying last year's model, so that organisms that don't fall into the nested hierarchy (a crocoduck, for instance), would be predictive of intelligent design. The nested hierarchy needs to be consistent (=perfect or nearly so) so that we don't see crocoducks.
No, Intelligent Design has no predictions, so a crocoduck would not be evidence for ID. It would be evidence against evolution, of course.
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Old 14th June 2017, 08:46 AM   #15
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Originally Posted by Paul2 View Post
I'm talking with an Intelligent Design advocate who linked me to an article claiming that the nested hierarchy (morphological, I guess) has fatal problems in it -- for instance, the "flat face" of Sahelanthropus tchadensis and Diania, an early arthropod or ancestor thereof.

I can imagine several responses, I wonder which apply:

1. A few organisms that don't fit into the hierarchy doesn't cause the entire edifice to crumble. But wouldn't it merely take one or a few outliers to falsify the nested hierarchy as a predictive model in evolution? Or not?

2. These organisms don't cause a problem for the hierarchy because their place in the hierarchy is still being debated.

3. These organisms fit into the nested hierarchy without any problems.

Comments?
From the linked article:

"Does this sort of data absolutely refute universal common descent? Taken on a case-by-case basis, no of course not, and we’re not claiming it does."

The ID advocate is grossly overstating his case.

The fact that there are a few examples where the hierarchical relationships between a particular organism and its close relations is not easy to figure out does not in any way negate the principle of universal common decent. In determining relationships among extant species we are missing an enormous amount of information because all we have is the final product to examine, not the continuous line of descent. Indeed, there is probably a case to be made that the shorter the period of descent between two species, the less confusion there will be in assigning a relationship.
Regarding fossil species there is even more missing data because you are working with only fragmentary evidence of only the fossilizable parts of a given species (rarely soft parts, no behaviors, etc.). Indeed there is a famous example of confusion regarding even which parts belong to which species in a fossilized specimen.
Given these immense limitations it is remarkable how few difficulties there actually are.

The principle of universal common descent rests on a wide foundation of findings in disparate fields of geology, biology, embryology, paleontology, and molecular biology. These multiple independent lines of evidence all support one another and that is why science is so confident in the conclusion that all life has arisen from a single common ancestor.
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Old 14th June 2017, 07:12 PM   #16
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Originally Posted by Paul2 View Post
I'm talking with an Intelligent Design advocate who linked me to an article ...
The author is Casey Luskin who is currently a lawyer and previously a geologist, not a biologist. That article is the ID idiocy of throwing doubt on evolution = support for ID.
  • An implication of faking data by "evolutionary biologists attempt to force-fit organisms into the tree".
  • Borrowing a creationist lie of "The first and primary assumption of all evolutionary phylogenetic classification methodologies is that common ancestry is true."
    That phylogenetic trees exist is evidence for common ancestry. If there were no common ancestors than the trees could not be found !
  • Cherry picked quotes.
  • "Sahelanthropus tchadensis is widely touted as a human ancestor" is close to a lie because Sahelanthropus
    Quote:
    Sahelanthropus may represent a common ancestor of humans and chimpanzees, though no consensus has been reached yet by the scientific community.
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Old 15th June 2017, 01:20 PM   #17
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Thanks to all who replied, I think this gives me the info I need. Carry on if you wish, I'll still monitor activity in this thread and be active.
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Old 15th June 2017, 03:25 PM   #18
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Originally Posted by Roboramma View Post
Not really. Every species descends from some other. If some species doesn't fit within the nested hierarchy then there is a real problem.
How would an organism that is genetically both plant and animal fit within the nested hierarchy? There really are organisms that are literally mosiacs of distant branches of the evolutionary tree. None of the organisms mentioned in the evolutionnews article are, but here is one.

It does not pose much of a problem for evolutionary theory.
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Old 19th June 2017, 02:46 AM   #19
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Originally Posted by Earthborn View Post
How would an organism that is genetically both plant and animal fit within the nested hierarchy? There really are organisms that are literally mosiacs of distant branches of the evolutionary tree. None of the organisms mentioned in the evolutionnews article are, but here is one.

It does not pose much of a problem for evolutionary theory.
That's a good point, and very interesting. It's sort of the exception that proves the rule, however.
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