already examined homology's morphological claim-in other words
the invalidity of the evolutionist claim based on similarities
of form in living things-but it will be useful to examine
one well-known example of this subject a little more closely.
This is the "fore- and hindlimbs of quadrupeds," presented
as a clear proof of homology in almost all books on evolution.
Quadrupeds, i.e., land-living vertebrates, have
five digits on their fore- and hindlimbs. Although these may
not always look like fingers or toes, they are all counted
as "pentadactyl" (five-digit) due to their bone structure.
The hands and feet of a frog, a lizard, a squirrel, or a monkey
all have this same structure. Even the bone structures of
birds and bats conform to this basic design.
Evolutionists claim that all living things descended
from a common ancestor, and they have long cited pentadactyl
limb as evidence of this. But they know that this claim actually
possesses no scientific validity.
Even today, evolutionists
accept the feature of pentadactylism in living things among
which they have been able to establish no evolutionary link.
For example, in two separate scientific papers published in
1991 and 1996, evolutionary biologist M. Coates reveals that
pentadactylism emerged two separate times, each independently
of the other. According to Coates, the pentadactyl structure
emerged independently in anthracosaurs and amphibians.289
This discovery is a sign that pentadactylism
is no evidence for a "common ancestor."
Another matter which creates difficulties for
the evolutionist thesis in this respect is that these creatures
have five digits on both their fore- and hindlimbs. It is
not proposed in evolutionist literature that fore- and hindlimb
descended from a "common limb"; rather, it is assumed that
they developed separately. For this reason, it should be expected
that the structure of the fore- and hindlimbs should be different,
the result of different, chance mutations. Michael Denton
has this to say on the subject:
[T]he forelimbs of all
terrestrial vertebrates are constructed according to the
same pentadactyl design, and this is attributed by evolutionary
biologists as showing that all have been derived from a
common ancestral source. But the hindlimbs of all vertebrates
also conform to the pentadactyl pattern and are strikingly
similar to the forelimbs in bone structure and in their
detailed embryological development. Yet no evolutionist
claims that the hindlimb evolved from the forelimb, or that
hindlimbs and forelimbs evolved from a common source… Invariably,
as biological knowledge has grown, common genealogy as an
explanation for similarity has tended to grow ever more
tenuous… Like so much of the other circumstantial
"evidence" for evolution, that drawn from homology is not
convincing because it entails too many anomalies,
too many counter-instances, far too many phenomena which
simply do not fit easily into the orthodox picture.290
But the real blow dealt to the evolutionist claim
of the homology of pentadactylism came from molecular biology.
The assumption of "the homology of pentadactylism," which
was long maintained in evolutionist publications, was overturned
when it was realized that the limb structures were controlled
by totally different genes in different creatures possessing
this pentadactyl structure. Evolutionary biologist William
Fix describes the collapse of the evolutionist thesis regarding
pentadactylism in this way:
The older textbooks
on evolution make much of the idea of homology, pointing
out the obvious resemblances between the skeletons of the
limbs of different animals. Thus the `pentadactyl' [five
bone] limb pattern is found in the arm of a man, the wing
of a bird, and flipper of a whale, and this is held to indicate
their common origin. Now if these various structures
were transmitted by the same gene couples, varied from time
to time by mutations and acted upon by environmental selection,
the theory would make good sense. Unfortunately this is
not the case. Homologous organs are now known to
be produced by totally different gene complexes in the different
species. The concept of homology in terms of similar genes
handed on from a common ancestor has broken down.291
On closer examination, William Fix is saying
that evolutionist claims regarding "pentadactylism homology"
appeared in old textbooks, but that the claim was abandoned
after molecular evidence emerged. But, unfortunately, some
evolutionist sources still continue to put it forward as major
evidence for evolution.
M., "New paleontological contributions to limb ontogeny and
phylogeny," In: J. R. Hinchcliffe (ed.), Developmental
Patterning of the Vertebrate Limb, Plenum Press, New
York, 1991, 325-337; Coates M. I., The Devonian tetrapod
Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod
interrelationships and patterns of skeletal evolution,
transactions of the Royal Society of Edinburgh, 1996, vol.
87, pp. 363-421.
290 Michael Denton, Evolution: A Theory
in Crisis, Adler & Adler, Bethesda, MA, 1985, pp. 151,
154. (emphasis added)
291 William Fix, The Bone Peddlers:
Selling Evolution, Macmillan Publishing Co., New York,
1984, p. 189. (emphasis added)