T_aquaticus
(The Friendly Neighborhood Atheist)
201
That’s false. Always has been.
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group.[1] This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors.[2]
That has always been false. No theory is proven, including the theory of evolution. The whole point of the fossil record is to test the predictions made by the theory of evolution, specifically which features should and should not be found together in the same species.
We have DNA that comes directly from shared ancestry.
Now here’s the thing. What you appear to be claiming is that Tiktaalik was not the first creature to have this sort of fin structure, Instead it had inherited it from an earlier ancestor who, by coincidence had a different line of creatures that became the land creatures. In the mean time Tiktaalik found the structure advantageous in its own right. Of course you do not have this earlier ancestor but Tiktaalik proves the earlier ancestor must have existed. But you can’t show that Tiktaalik did inherit the feature, only that it had it. for all you know Tiktaalik was the first in its line to evolve that structure (but that would be helpful to you). So all it really shows is that some fish have similar bone structure to load bearing ones. All the rest is supposition, exposition and flannel.
Richard - if you’re going to ignore the person who has the capability and takes the time to give you the clearest answers, then it is pointless for you to continue here. If you can’t take the heat, then you should leave the kitchen. I can help with that if needed.
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T_aquaticus
(The Friendly Neighborhood Atheist)
204
Nope, Tiktaalik’s ancestors found the features advantageous and passed it on to Tiktaalik. Those same ancestors also passed the advantageous features to the species in the direct line leading to modern tetrapods.
What we do know is that the theory of evolution predicted we would find fossils with a mixture of features from lobe finned fish and tetrapods, and that’s exactly what we found.
You are forgetting that those exact features were predicted by the theory of evolution.
Oh, so now ignoring someone who asks stupid questions and I get into trouble answering is a crime!. What is the point of having a mechanism if I get penalised for using it! I was even told to put him on ignore once! It seems I can’t win.
As it happened I took a peak at his last response to me and it did not give any “answers” only questions that I have already covered.. So I was right. Sorry and all that.
The only way out of this dilemma is to look at Ring Species…. where the 2 ends of a population range are not sexually compatible (or less so) than any 2 adjacent population sub-groups. But we only have a few of them. The rest is of the fossil record is DEDUCTIVE.
But I thought you wrote that you weren’t going to assume a miracle unless there was evidence of it.
In this case, you are ASSUMING De Novo creation of the legged fish’s ancestors.
You really should stop saying you believe in Evolution at all.
That’s a pity, because it means you won’t see Darwin’s explanation.
But here’s Wikipedia:
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors.
I never mentioned miracles. Nor have I claimed any spectacular Godly intervention. All I am showing is that the evidence does not promise what is concluded.
Please distinguish between a destructive crit and an alternative suggestion. I have offered no such suggestion or assertion.
Does a food critic have to supply the solution to the criticism? They do not even have to be cooks!
Richard
T_aquaticus
(The Friendly Neighborhood Atheist)
209
Ahlberg and Clack have a great article in Nature that exemplifies how the transitional nature of fossils is defined by their morphology, not on an insistence on the fossil being in the direct ancestral lineage.
The concept of ‘missing links’ has a powerful grasp on the imagination: the rare transitional fossils that apparently capture the origins of major groups of organisms are uniquely evocative. But the concept has become freighted with unfounded notions of evolutionary ‘progress’ and with a mistaken emphasis on the single intermediate fossil as the key to understanding evolutionary transitions. Much of the importance of transitional fossils actually lies in how they resemble and differ from their nearest neighbours in the phylogenetic tree, and in the picture of change that emerges from this pattern.
My colleague Jenny Clack at Cambridge University and others have uncovered amphibians from rocks in Greenland that are about 365 million years old. WIth their necks, their ears, and their four legs, they do not look like fish. But in rocks that are about 385 million years old, we find whole fish that look like, well, fish. They have fins, conical heads, and scales; and they have no necks. Given this, it is probably no great surprise that we should focus on rocks about 375 million years old to find evidence of the transition between fish and land-living animals.
Neil Shubin, 2008. Your Inner Fish. Pantheon Books, New York, 0375424472. P. 10.
The focus has always been on the combination of features in a given fossil and how they were predicted by the theory of evolution in both morphology and in time.
Also:
As to the actual rarity of fossils illustrating evolutionary transitions, Explore Evolution makes additional errors. First, fossils in general are rare, relative to the actual diversity of life which once existed. The chances of a given species fossilizing are slight. Thus, the fossils referred to as transitional are not necessarily the direct ancestors of modern taxa, but may represent failed branches off of the stem which led to modern forms. Depending where they branched off, they possess some, but not all, of the traits we associate with modern groups, which provides evidence of the form the transition took, even if we lack fossils of the directly ancestral species.
