Morphologically intermediate species

Lee A. Spencer, Ph.D. (spencerl@swau.edu)
Tue, 25 Feb 1997 09:39:06 -0600

It has been interesting to read the debate about archaeopteryx. However,
archae is not a bird with reptile teeth. It is really a reptile with
feathers. Of the characters usually assigned to birds that archae shares,
only two are uniquely avian: feathers and an opposable hallux (and maybe not
feathers). The furcula has been found in dinosaurs (Bryant and Russell,
1993, Jour. Vert. Paleo. 13(2):171-184). It has many more characters that
are found only in reptiles (see Archaeopteryx FAQ, Talk.Origins.Archive).
The reptile/mammal series is even more interesting.

The existance of morphological intermediates by itself does not prove or
disprove any specific cosmology because one can always propose hypotheses
for the existence of these rare cases. They do not prove evolution because
the necessary steps from one form to another are still missing; archae is
only one of many steps that would be necessary to evolve from a reptile to a
bird. The missing steps are explained away by the ad hoc statement of
incompleteness of the fossil record. Similarly, creationists can also
explain away the problem by the ad hoc statement that God originally created
a more complete scale of nature, most species of which are now extinct.
Either of these ad hoc statements have equal probability of being true until
tested. What creationists cannot do, however, is argue that morphological
intermediates do not exist. Creationists need to spend less efffort
attacking evolution and more time devising testable hypotheses consistent
with their cosmology, and then changing their hypotheses to remove those
aspects that have been falsified.
Lee A. Spencer, Ph.D.
Vertebrate Paleontologist
Southwestern Adventist University
Keene, Tx 76059