Page 142 - The Transitional Form Dilemma

THE TRANSITIONAL-FORM DILEMMA

The Coelacanth
The Coelacanth
Belonging to the class Osteichthyes, this is a large species of fish
some 150 centimeters (59 inches) long and covered in thick scale resem-
bling armor plating. Its first fossil remains are found in strata from the
Devonian Period, 408 to 360 million years old. Until 1938, many evolu-
tionist ichthyologists assumed that this creature had walked along the
sea bed, using its two pairs of giant fins, and that it represented a transi-
tional form between sea and land animals. To support these claims, evo-
lutionists pointed to the bony structures in the fins of the coelacanth
fossils in their possession.
A development in that year, however, totally undermined these
claims. A living coelacanth was caught in the sea of Madagascar!
Moreover, studies on this species, thought to have disappeared at least
70 million years ago, showed that it had undergone no changes at all for
400 million years.
In its April 2003 issue, Focus magazine described the astonishment
this caused:
Even the discovery of a living dinosaur would have been less surprising.
Because fossils show that the coelacanth existed 150-200 million years before
the appearance of the dinosaurs. The creature put forward by many scientists
as the ancestor of land-dwelling vertebrates, believed to have disappeared at
least 70 million years ago, had been found 110
Subsequent years saw the capture of another 200 or so living coela-
canths (Latimera chalumnae). It was realized that these fish, which had re-
mained completely unaltered, lived at depths of 150 to 600 meters (.093
to .372 of a mile) and possessed a perfect body design. In 1987, Professor
Hans Fricke of the Max Planck Institute descended in the mini-sub Geo
to a depth of 200 meters (.124 of a mile) near the Comoro islands to the
east of Africa and observed these fish in their natural environment. He
saw that their bony fins had no function equivalent to the extensions in
tetrapods (four-legged land animals) that allow them to walk on land.

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