What does Homology show proof of , Evolutionary Naturalism or an Intelligent Designer?

Homology involves the theory that macroevolutionary relationships can be proven by the similarity in the anatomy and physiology of different animals. Since Darwin, homology has been cited in textbooks as a major proof for evolution. But a review of the literature on homology indicates that the theory does not provide evidence for evolutionary naturalism. Furthermore, increased knowledge about the genetic and molecular basis of life has revealed many major exceptions and contradictions to the theory which, as a result, have largely negated homology as a proof of evolution.

Evolutionary Naturalism

Evolutionists claimed that extensive comparisons of skeletons, muscles, nerves, body organs, cell ultrastructure and biochemistry of different animal kinds have confirmed that a great deal of similarity exists in both their structure and function. By arranging or classifying large sets of anatomical structures according to the similarity of selected traits, evolutionary naturalists have attempted to demonstrate evidence for a long, gradual line of progressive animal changes terminating in the highest organism yet, humans. Evolutionists then argue that these comparisons prove the concept that all life evolved from a hypothetical ‘common ancestor’ protocell that they believe lived about 3.5 billion years ago.

‘If you look at a 1953 Corvette and compare it to the latest model, only the most general resemblances are evident, but if you compare a 1953 and a 1954 Corvette, side by side, then a 1954 and a 1955 model, and so on, the descent with modification is overwhelmingly obvious. This is what paleontologists do with fossils, and the evidence is so solid and comprehensive that it cannot be denied by reasonable people.’

Homology is not merely a minor proof of evolution, but instead has been widely cited by evolutionists as one of the most compelling lines of evidence for their theory. Darwin concluded that homology was critically important evidence for common descent:

‘According to Darwin’ theory of common descent, the structures that we call homologies represent characteristics inherited with some modification from a corresponding feature in a common ancestor. Darwin devoted an entire book, The Descent of Man and Selection in Relation to Sex, largely to the idea that humans share common descent with apes and other animals … . Darwin built his case mostly on anatomical comparisons revealing homology between humans and apes. To Darwin, the close resemblances between apes and humans could be explained only by common descent.’

Darwin reasoned that the members of the same class of animals resemble each other in the general plan of their design and, in his words, this resemblance is critical because of the fact that ‘the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the tortoise and the wing of the bat’ are all ‘constructed on the same pattern’ and ‘include similar bones in the same relative positions’ is specifically what the theory of common descent would expect. The argument from homology has been used in high school and college biology textbooks for generations. A survey by the author of 45 widely used recent college textbooks and 28 high school texts revealed that all of those that discussed evolution (except one) employed homology as a major proof for Darwinism. Most discussions were brief and almost identical in content and thrust. The following example was typical:

‘The seven bones in the human neck correspond with the same seven, much larger, neckbones in the giraffe: they are homologues. The number of cervical vertebrae is a trait shared by creatures descended from a common ancestor. Related species share corresponding structures, though they may be modified in various ways.’

These fundamental resemblances, or homologies, as they are technically called, call for some explanation, and the only natural explanation that has ever been proposed is evolution.’ ‘Why is it that bats and whales have so much in common anatomically with mice and men? Why do virtually all vertebrate forelimbs have the same basic "pentadactyl" (five fingered) design?

However, homology does not prove evolution, in the sense that nobody has actually witnessed the gradual changes in the millions of consecutive generations which led from a common ancestor to a bird on the one hand and to man on the other. But, only homology strongly suggests evolution.

Origin of the Homology theory

The concept of homology originally meant only that a set of structures was fundamentally similar. It was first elaborated in 1843 by one of Darwin’ most informed critics, Sir Richard Owen. Before Darwin, homology observations were explained by a concept called ideal archetypes, meaning the Creator used the superior design prototype throughout His Creation. A branch of this worldview now is called INTELLIGENT DESIGN THEORY.

It was not until after Darwin that homology implied common ancestry. After Darwin’ ideas spread, the structural similarity in many animals that had been obvious to anatomists for generations was reinterpreted as evidence for common descent.

Evaluation of Homology as evidence

That some similarity exists when certain aspects of life forms are compared is obvious.

The simplest and most obvious explanation for the fact that morphological similarities between bones, sensory organs, lungs, or gills exist among most higher animals is that the requirements of life are similar for similar living things, and some designs are preferred in constructing animals because these designs are superior to competing designs.

All automobile, bicycle and pushcart tyres are round because this design is superior for the function of most tyres. A tyre homology does not prove common descent, but common design by engineers throughout history because of the superiority of the round structure for rolling. Likewise, most vertebrate kidneys are similar structurally because they have a similar physiological role in the body and consequently must be similar in both structure and function.

Homology also does not prove that a set of animals is related by descent because both similarities and differences exist for any two animal types, and traits often are chosen by evolutionists only because they seem to provide evidence that two animals are related. The only criterion that was used by Darwinists to select examples of homology was: ‘Does the example support what is assumed to be an evolutionary relationship?’ Other examples are ignored or explained away. This fact is so well recognized, and so many examples exist that contradict the explanation of common descent.

EVIDENCES :

A.) Homology and Anatomy
B.) Vestigial Organs and Homology 
C.) Embryology and Homology
D.) BioChemical Homology
E.) Genetics and Homology


Conclusion

As scientists learn more about anatomy, physiology and especially genetics, the concept of homology increasingly came under attack. One problem however, was that examples which seemed to fit evolutionary assumptions were often cited, while the many examples that do not fit were ignored. And, in time, more and more examples were discovered that had to be ignored. Eventually, as one observer noted, homology led Darwinists to assemble very select examples that seemed to prove ancestor-descendant relationships that often were quite convincing. In addition, as Milton has observed,

The recent information explosion in embryology, microbiology, genetics and especially molecular biology has revealed in minute detail how plants and animals are constructed at the molecular level. If the Darwinian interpretation of homology were correct, then we would expect that the same homologies found at the macroscopic level also exist at the microscopic, biochemical and genetic levels. What researchers in each of these fields often find, has greatly undermined the homology concept. So many exceptions now exist that molecular biologist Michael Denton concluded that the homology theory should be rejected. His main argument is that genetic research has not shown that homologous structures are produced by homologous genes and follow homologous patterns of embryological development. Instead, genetics has found that homologous structures are ‘often specified by non-homologous genetic systems’ and furthermore, the homology ‘can seldom be extended back into embryology’.

Why do most scientists accept macroevolution theory?

A major reason is that it is now the accepted world view of scientists—an idea to which they are exposed from the earliest days of training, and by which they are surrounded daily. Most scientists are influenced by social pressure, and many believers fear recriminations from their fellow scientists if they do not conform to what currently is viewed as correct. To prove their orthodoxy, many scientists have become unscientific. Belief in evolutionism requires a credulity induced partly by pressure to conform to a world of science that is saturated with naturalism.

What do YOU think? Are you for Evolutionary Naturalism or Intelligent Designer ? . . .