Bronze-level articleTransitional fossil

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A transitional fossil is a fossil of an organism that has traits from multiple evolutionary stages. Proponents of creationism claim that "evolutionists have had over 140 years to find a transitional fossil and nothing approaching a conclusive transitional form has ever been found", despite the discovery of Archaeopteryx (a transitional form between maniraptoran dinosaurs and basal (primitive) birds, and among the best examples of evolution) only two years after Darwin published The Origin of Species. Creationists say that we never saw evolution happen, but transitional fossils are the next best thing.


[edit] Examples of transitional fossils

Since then, many other transitional forms, such as Ambulocetus and Pakicetus[1][2] (land mammals to marine cetaceans), and Tiktaalik[3] and Acanthostega[4] (fish to tetrapods) have been found.

The National Academy of Sciences has commented on the abundance of transitional forms: "So many intermediate forms have been discovered between fish and amphibians, between amphibians and reptiles, between reptiles and mammals, and along the primate lines of descent that it often is difficult to identify categorically when the transition occurs from one to another particular species."[5]

[edit] Creationist denial

What was that about half a wing not being useful?

Finding transitional forms never impresses creationists. If a transitional form B, between known species A and C is found, they demand "transitional forms" between A & B and B & C, a demand that is essentially unfulfillable at the individual level, such as at a parent-child case where no "transitional form" occurs. Apparently, the only thing that would satisfy them is a complete set of generation-by-generation fossils of every life-form in a direct line of descent from the first bacteria to Charles Darwin's grand-father[6] However, due to the rarity of the fossilisation process, this is unlikely to occur, although new finds are being made which add to the information provided by the fossil record.

[edit] See also

[edit] External links

There is an overview of many of these at

For the truth on transitional forms, see wikipedia

[edit] Footnotes

  1. Fossil Evidence for the Origin of Aquatic Locomotion in Archaeocete Whales, in Science 14 January 1994
  2. Ambulocetus as a Fossil Transitional, Lenny Flank, 1995
  3. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan, in Nature 6 April 2006.
  4. Acanthostega: TOL
  6. Erasmus Darwin. Only the rockingest 18th century doctor evar!

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