Gould: Evolution as Fact and Theory

Continuing the discussion from Eight ways evangelicals are driving Americans to atheism:

This is a great article to read in full.

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Apart from “geology” (which is different to “fossils”), everything else you listed there is biology. Do you understand that?

One of the classic quotables from the essay:

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You could have stopped right there, and probably should have.

Its infuriating for creationists to be told they got this wrong. We did not!
PE is a desperate attempt to rescue the fossil record from its absence of population changes as it should show if evolution was true.
These larger groups are too large. they don’t count.
Anyways its about no transitional forms between anything lower then “groups/whatever a group is”
That was why he thought he deserved to be seen as a accomplished evolutionist. A novel idea. PE.
In short the fossil record does not show Darwins endless stages in creatures evolving. but instead only shows after they evolved, but had become reproductively successful, and so the times of small populations evolving are not as likely to be caught by the fossil record.

Stephen Jay Gould:

Transitional forms are generally lacking at the species level, but they are abundant between larger groups.

The two clauses of this statement, if taken as true, contradict each other:

  1. All fossils belong to species (perhaps now extinct, but members of species when the fossils were living things).

  2. All larger groups of higher taxonomic rank – genera, families, orders, et cetera – are constituted of species.

  3. Therefore: if “transitional forms” exist between larger groups, they also exist between species, by necessity, and the first clause of Gould’s statement is false.

  4. OR: if Gould’s first clause is true, then “transitional forms” do not exist between larger groups either, and the second clause is false.

Logical thickets or messes such as this led the cladists to dump the entire concept of “transitional forms” in the late 1970s. Gould himself, of course, rejected cladistic methodology.

Not if you actually understand them. He refers, in the first clause, to transitions between direct ancestor-descendant species, which are not only very rare but practically impossible to know (that’s the cladistics bit). In the second clause he refers to species with transitional characters uniting higher taxa, which are common enough for many purposes.

Not true at all. Where did you get that idea? Transitional forms remain; they are just no longer interpreted as direct ancestors of groups. The reason: we can’t tell based on the fossil record whether a taxon is an ancestral species or a cousin of the ancestral species. Fortunately, cousins are enough to show the path of evolution. Gould’s rejection of cladistics has nothing to do with any of this.

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Deeper into the logical thicket, John.

Transitional forms remain; they are just no longer interpreted as direct ancestors of groups.

So the “transitional form” is a transition between…what? Please show me an example of ranks, higher than species, giving rise (i.e., providing direct ancestry) to other such groups. And what is a “transitional character,” in fossils, if not an intermediate morphology between two species which stand in a direct lineage with each other?

Elsewhere on this discussion site, you said that the term “corollary ancestor” (cousin) is nonsense, as an indicator of actual lineage or descent. Have you changed your mind?

Gould used to wear a t-shirt with the motto “I [heart symbol] paraphyly.” He liked paraphyly because it made ancestor-descendant claims easier to assert.

It isn’t a question of whether they existed. It is a question of the probability of finding their fossils.

You may need to flesh this out a bit and explain how cladistics has dumped the concept of transitional forms (I am guessing you are confusing ancestral forms and transitional forms). From what I have read, Gould doesn’t so much reject cladistics as much as pointing to its weaknesses, and the weaknesses of all other systems of classification.

http://courses.ischool.utexas.edu/Lease_Matt/2010/Fall/INF384C/readings/gould_zebra.pdf

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Fascinating that you, who have studied evolution so much, don’t know any of this. Transitional forms show transitional states and show what happened in the ancestral line, even though they are not themselves ancestors. Presumably you have seen cladograms. The ancestors are at the internal nodes, and the actual species are at terminal nodes. But we can infer the states at internal nodes based on those at terminal nodes.

I have said no such thing. I believe what you have there is a garbled reference to “collateral ancestor”. And yes, that term is nonsense, because they aren’t ancestors. But non-ancestors can still be transitional forms if they show a combination of primitive, derived, and/or intermediate states.

Yes, he was confused. But that doesn’t mean you have to be too.

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…and of recognizing them if we happen to find them.

I would also suggest that it’s impossible, using the fossil record, to tell if two fossils belong to the same species or to separate but closely related ones, or to distinguish speciation from anagenesis from range expansion. The biological species concept doesn’t work if extended over evolutionary time scales; reproductive isolation is not a preserved character.

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There are no identifiable species – actual biological ancestors – at internal nodes. Internal nodes are abstractions, based on the character distributions at the terminals. No abstraction was ever the ancestor to anything.

Using sister-group relationships solves the problem of having to show actual ancestry (something fossils can never do), at the cost of destroying entirely what we normally understand to be ancestor-descendant relationships.

Yes, I meant “collateral ancestor,” thank you for the correction.

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That’s what I said. But this is not a weakness of cladistics; it’s a strength, because it restricts our claims to what can actually be shown. Yes, we can’t identify ancestor-descendant relationships among species. And yet the cladograms show that such relationships do exist. Species are related by common descent, and that implies ancestors, even if we can’t point to them. That’s how science works, you know: by inference from data.

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Only on the assumption of common ancestry.

I would phrase it differently. We have no way of determining the ancestors or descendants of any fossil. If you dug up a human skeleton you wouldn’t be able to determine who its ancestors or descendants were by just its morphology. Does this mean the human specimen had no ancestors or descendants? Obviously not.

That’s why they are described as transitional fossils.

Or, as Darwin put it:

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Like all YECs you confuse assumptions with conclusions. Must we discuss the implications of nested hierarchy? Must we argue about whether that hierarchy actually exists?

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Nested hierarchies antedate Darwin and the theory of common descent by many decades. The workers who used them (e.g., Linneaus, Cuvier) did not infer, from the presence of a hierarchy, common ancestry.

You do, making assumptions about what an intelligent designer would be likely to do.

I take a nominalist view of nested hierarchies. They represent information retrieval systems. My nominalist interpretation is supported by many thousands of anomalous character distributions, typically dumped into a bin labelled “not phylogenetically informative.”

No more replies from me in this thread: Peaceful Science is a time-consuming habit I only indulge when I forget that I have a day job to do. :wink:

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Darwin did.

Can you name a single reason why an intelligent designer would be forced to use the same pattern of differences and similarities that evolution would produce? Moreover, humans regularly violate a nested hierarchy when we are designing organisms. I have done it myself.

Why would an information retrieval system need to be a nested hierarchy? This makes no sense.

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True. But so what? They had no explanation for nested hierarchy. (“God wanted it that way” is of course not an explanation for anything.)

Good for you. But that isn’t an explanation either. You seem, in your own vague way, to be denying that this nested hierarchy is a real phenomenon but merely a matter of convenience. The data show you are wrong.

Aaand I see you have flounced.

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I can! He would be forced to do this if he predetermined he would create everything by a process of common descent.

Why do this way? Well, why not? He had to do it somehow, and this is how he did it.

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