The discovery
which really overthrew homology is that organs accepted as
"homologous" are almost all controlled by very different genetic
codes. As we know, the theory of evolution proposes that living
things developed through small, chance changes in their genes,
in other words, mutations. For this reason, the genetic structures
of living things which are seen as close evolutionary relatives
should resemble each other. And, in particular, similar organs
should be controlled by similar genetic structures. However,
in point of fact, genetic researchers have made discoveries
which conflict totally with this evolutionary thesis.
Similar organs are usually governed by very different
genetic (DNA) codes. Furthermore, similar genetic codes in
the DNA of different creatures are often associated with completely
different organs. The chapter titled "The Failure of Homology"
in Michael Denton's book, Evolution: A Theory in Crisis,
gives several examples of this, and sums the subject up in
this way:
Homologous structures
are often specified by non-homologous genetic systems and
the concept of homology can seldom be extended back into
embryology.285
This genetic question has also been raised by
the well-known evolutionary biologist Gavin de Beer. In his
book Homology: An Unsolved Problem, published in
1971, de Beer put forward a very wide-ranging analysis of
this subject. He sums up why homology is a problem for the
theory of evolution as follows:
What mechanism can it
be that results in the production of homologous organs,
the same 'patterns', in spite of their not being controlled
by the same genes? I asked this question in 1938, and it
has not been answered.286
Although some 30 years have passed since de Beer
wrote those words, they have still received no answer.
A third proof which undermines
the homology claim is the question of embryological development,
which we mentioned at the start. In order for the evolutionary
thesis regarding homology to be taken seriously, the periods
of similar structures' embryological development-in other
words, the stages of development in the egg or the mother's
womb-would need to be parallel, whereas, in reality, these
embryological periods for similar structures are quite different
from each other in every living creature. Pere Alberch, an
eminent developmental biologist, noted, it is "the rule rather
than the exception" that "homologous structures form from
distinctly dissimilar initial states."287
The emergence of similar structures
as the result of totally dissimilar processes is frequently
seen in the latter stages of the development phase. As we
know, many species of animal go through a stage known as "indirect
development" (in other words the larva stage), on their way
to adulthood. For instance, most frogs begin life as swimming
tadpoles and turn into four-legged animals at the last stage
of metamorphosis. But alongside this there are several species
of frog which skip the larva stage and develop directly. But
the adults of most of these species that develop directly
are practically indistinguishable from those species which
pass through the tadpole stage. The same phenomenon is to
be seen in water chestnuts and some other similar species.288
To conclude, we can say that genetic and embryological
research has proven that the concept of homology defined by
Darwin as "evidence of the evolution of living things from
a common ancestor" can by no means be regarded as any evidence
at all. The inconsistency of homology, which looks quite convincing
on the surface, is clearly revealed when examined more closely.

The fact that almost all land-dwelling vertebrates have
a five-toed or "pentadactyl" bone structure in their
hands and feet has for years been presented as "strong
evidence for Darwinism" in evolutionist publications.
However, recent research has revealed that these bone
structures are governed by quite different genes. For
this reason, the "homology of pentadactylism" assumption
has today collapsed. |
  
285 Michael
Denton, Evolution: A Theory in Crisis, Burnett Books,
London, 1985, p. 145.
286 Gavin De Beer, Homology: An Unsolved
Problem, Oxford University Press, London, 1971, p. 16.
287 Pere Alberch, "Problems with the Interpretation
of Developmental Sequences," Systematic Zoology,
1985, vol. 34 (1), pp. 46-58.
288 Raff, Rudolf A., The Shape of Life:
Genes, Development, and the Evolution of Animal Form,
The University of Chicago Press, Chicago, 1996. |