Do transitional fossils prove evolution? Does those who believe in evolution commit the logical fallacy of...?

Question

Do transitional fossils prove evolution? Does those who believe in evolution commit the logical fallacy of affirming the consequent?

Here is a quote from an article that I found on the website of California Academy of Sciences by the title" "Fish Out Of Water" the article states that "the bones inside animal’s forward fins provide evidence of arms in the making" Read the full article here: http://www.calacademy.org/science_now/headline_science/fossil_fish.php

So the argument is this as I understand it:
If evolution is true than transitional fossils will be found
The tiktaalik is a transitional fossil since it has a bone inside of its forward fins which provide evidence of arms in making.
Therefore evolution is true

An example of the same fallace:
If it's raining then the streets are wet.
The streets are wet.
Therefore, it's raining.

In symbolic form it looks like this

If p then q.
q.
Therefore, p


to learn more about this fallacy go to http://www.fallacyfiles.org/afthecon.ht

Thanks for all the responses. So is evolution constructed based on inductive arguments that are judged by degree of probability?

Answer 1

injanier hit the answer squarely on the head. I can only reinforce it.

The problem is *starting* with the fallacy of saying that science claims that fossils "prove" evolution. Fossils are one piece of *evidence* for evolution. And evidence is *cumulative* ... nothing is ever "proved" (as it is in the mathematics of logic), but rather confidence in the truth of a statement *grows* as more evidence accumulates.

The very quote you gave uses the word "provides evidence" ... not "proves."

So the logic of science is more like:

If it's raining, then the streets will be wet.
The streets are wet.
Therefore we have *evidence* that it is raining.

... And if added to other evidence (the sound of raindrops, the feel of raindrops as we step outside, an overcast sky, the water in the gutters, sogginess of the back yard, the "90% chance of showers" weather report, etc.), our confidence in the statement "it is raining", starts to grow.

OR (better):

If the streets are dry, then it cannot be raining.
The streets are wet.
Therefore our theory that it is raining still stands (it has not been disproved).

So that article is exactly right. The structure of the tiktaalik fin is consistent with that of a transitional form between fins and feet. This is *evidence* that tiktaalik is a transitional form ... to be added to all the other evidence from other structures and other fossils. That does not "prove" evolution. But it certainly refutes the claim that "there are no transitional forms."

>"So is evolution constructed based on inductive arguments that are judged by degree of probability?"

... and parsimony.

Faced with a *set* of evidence (streets are wet, hear raindrops, feel them when stepping outside, gutters are flowing, back yard is soggy, sky is overcast, weather report says "90% chance of showers") ... we can come up with multiple theories:

A - It is raining.

B - Someone is playing an elaborate hoax ... soaking the streets and lawns with hoses, spigoting water into the gutters, spraying water on the house from silent helicopters to simulate the sound and feel of raindrops, shielding the sun with massive cloud-shaped balloons to make it "look" overcast, faking weather reports.

C - We are unknowingly living in a movie set, in which all of the above is just manufactured evidence (see the movie The Truman Show).

We have to go with A ... not for reasons of logic or probability, but simply for reasons of parsimony. That does not "prove" A ... theory B or C may possibly be true. But as scientists we must go with the theory that introduces the fewest assumptions.

Answer 2

Speaking as a scientist (My faith has never interfered with believing in Evolution--only my scientific inquiry has) These are not transitional fossils. A transitional fossil would be a creature that is developing something that wasn't there before. For example, a skeleton. You cannot have a species without a skeleton, and suddenly there's one with a complete and working skeleton. It's too complicated--there must be in between steps that show how something would go from a cartilage creature to a creature with some hardened, bone like parts, to developments of joints etc. If evolution comes from additional genetic material thru mutations, then not only should we see these partial not fully developed transitional states of complex structures in the fossil record, but we should also see them occurring today with the millions of species we know about, we should see some of them beginning, in the middle of or at the end of the change. What about humans? Well, the only additional genetic material being added that I know of (and I'm no expert) would be those with Down's syndrome (they have an extra gene) and those with the XXX and XYY sex genes. This could be an argument showing how evolution might take place.

Answer 3

Creationist MO:

1. Claim that transitional fossils are hugely important in the Evolution/Creationism debate.
2. Make up their own definition of what constitutes a transitional fossil so that the hundreds of examples "don't count."
3. Repeat loudly that this is a smoking gun: no transitionals = no evolution.

Then a beautiful example of a transitional fossil shows up. One that even a child can understand and interpret. So what do the creationists do?

They accuse scientists of basing the entire validity of the theory of evolution on the existence of these fossils. Which of course isn't logical.

So, um, logically, the theory of evolution must be false?

Shame on you, Creationists, for even hinting that the scientific community is as stupid as the Creationist community.

Answer 4

First of all, everything is a transitional form. Even you. You're a transitional form between your parents and your children.

The second one you listed is indeed a fallacy - because the streets can be wet after it's done raining or for another reason. However, there is no other reason that has been proposed for why there are transitional fossils. So evolution is the best theory we have.

Answer 5

I think the operant logical fallacy here is the straw man fallacy. You are misrepresenting the evolutionary argument to try to discredit evolution.

No scientific theory, including evolution, is capable of absolute logical proof. So although you have constructed a genuine logical fallacy, you fail to connect it to anything actually said in support of evolution, because no scientist is going to claim that a single piece of evidence "proves" evolution. The evidence presented *supports* evolution.

If you would read the article you have cited, you would see that what is actually being claimed is that this fossil is yet one more piece of evidence that *disproves* the persistent creationist claims that there are no transitional fossils.

Answer 6

Neither transitional fossils nore any other fossils prove anything.. They are simply evidentiary facts that support the conclusion that Evolution is a valid explanation for the history and diversity of life on the Earth

Answer 7

Look about you now. Millions of animals die every year but few - none - are fossilised. The chances of finding any fossil from a time long gone by are minute let alone a series which show a transition.
RoyS

Answer 8

When Darwin put his evolutionary hypothesis forward he expected that countless transitional fossils would be found.
Evolution postulates that that such creatures existed and it is a big problem that they have not been found.

This is why Gould invented his 'punctuated equilibrium' theory - things changed so quickly that that they didn't leave any fossil evidence, and then stayed the same for ages.
But there is no evidence for this idea - it was invented to try and explain the evidence.

The fact of the matter is that there are just a handful of highly controversial 'transitional' fossils.

Injanier above is wrong to suggest that transitional fossils disprove creation. In fact the fossil record is a vindication of the creationist position. The fossils show stasis and extinction - exactly what one expects from the Biblical account of creation and the Flood.

Recall that the Coelacanth fish was paraded as a transitional fossil of an extinct fishy animal with legs - until someone discovered them alive and well - just a fish!

There are *no* transitional fossils that unambiguously link any major groups of animals. Just some just-so stories, which are philosophy but not science.

http://www.creationontheweb.com/content/view/3832/

Dr Eldredge [curator of invertebrate palaeontology at the American Museum] said that the categories of families and above could not be connected, while Dr Raup [curator of geology at the Field Museum of Natural History in Chicago] said that a dozen or so large groups could not be connected with each other. But Dr Patterson [a senior palaeontologist and editor of a prestigious journal at the British Museum of Natural History] spoke most freely about the absence of transitional forms.

Before interviewing Dr Patterson, the author read his book, Evolution, which he had written for the British Museum of Natural History. In it he had solicited comments from readers about the book’s contents. One reader wrote a letter to Dr Patterson asking why he did not put a single photograph of a transitional fossil in his book. On April 10, 1979, he replied to the author in a most candid letter as follows:

‘… I fully agree with your comments on the lack of direct illustration of evolutionary transitions in my book. If I knew of any, fossil or living, I would certainly have included them. You suggest that an artist should be used to visualise such transformations, but where would he get the information from? I could not, honestly, provide it, and if I were to leave it to artistic licence, would that not mislead the reader?
’I wrote the text of my book four years ago. If I were to write it now, I think the book would be rather different. Gradualism is a concept I believe in, not just because of Darwin’s authority, but because my understanding of genetics seems to demand it. Yet Gould and the American Museum people are hard to contradict when they say there are no transitional fossils. As a palaeontologist myself, I am much occupied with the philosophical problems of identifying ancestral forms in the fossil record. You say that I should at least “show a photo of the fossil from which each type of organism was derived.”? I will lay it on the line- there is not one such fossil for which one could make a watertight argument. The reason is that statements about ancestry and descent are not applicable in the fossil record. Is Archaeopteryx the ancestor of all birds? Perhaps yes, perhaps no there is no way of answering the question. It is easy enough to make up stories of how one form gave rise to another, and to find reasons why the stages should be favoured by natural selection. But such stories are not part of science, for there is no way of putting them to the test. ‘So, much as I should like to oblige you by jumping to the defence of gradualism, and fleshing out the transitions between the major types of animals and plants, I find myself a bit short of the intellectual justification necessary for the job …’

[Ref: Patterson, personal communication. Documented in Darwin’s Enigma, Luther Sunderland, Master Books, El Cajon, CA, 1988, pp. 88–90.]
http://www.creationontheweb.com/content/view/1918