What can be more curious than that the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the porpoise, and the wing of the bat, should all be constructed on the same pattern, and should include similar bones, in the same relative positions?
Curious indeed. This example is today a staple in the apologetics literature. Look in any textbook or popular work demonstrating the fact of evolution, and you are likely to see a graphic showing various pentadactyl structures in the tetrapods. Here is how evolutionist Mark Ridley echoes Darwin’s original interpretation in his Evolution textbook:
Other similarities between species are less easily explained by functional needs. The pentadactyl (five-digit) limb of tetrapods is a classic example. … Tetrapods occupy a wide variety of environments, and use their limbs for many differing functions. There is no clear functional or environmental reason why all of them should need a five-digit, rather than a three- or seven- or 12-digit limb. And yet they all do. … The evolutionary explanation of the pentadactyl limb is simply that all the tetrapods have descended from a common ancestor that had a pentadactyl limb and, during evolution, it has turned out to be easier to evolve variations on the five-digit theme, than to recompose the limb structure. If species have descended from common ancestors, homologies make sense; but if all species originated separately, it is difficult to understand why they should share homologous similarities. Without evolution, there is nothing forcing the tetrapods all to have pentadactyl limbs.
Here is how the Public Broadcasting Service evolution site explains the evidence:
The limbs of tetrapods all have the same pattern of bones. Darwin was one of the first to comment that it seems unlikely that this single skeletal structure could be the best one possible for each of the activities it is required to perform in different animals. … If you want to see concrete evidence of evolution, look no further than your hand or your foot. Five fingers, five toes. There's nothing magical about the number, yet five digits at the end of their limbs is a motif that runs through all the animals with four limbs, called tetrapods. … Pentadactyly (having five digits) is, in fact, an accident of evolutionary history.
And here is how evolutionist Douglas Futuyma put it:
If God had equipped very different organisms for similar ways of life, there is no reason why He should not have provided them with identical structures, but in fact the similarities are always superficial.
But as usual, the evolutionary apologetics are less convincing than evolutionists believe. In this case there are four different problems with this evidence and the evolutionary arguments.
Four problems with the evidence
The first problem is that evolution has no scientific explanation for the origin of the pentadactyl structure. Amazingly, evolutionists cannot account for the evolution of the very structure they claim proves their theory.
The second problem is that evolutionists are having it both ways. When they find a biological pattern, such as the pentadactyl structure, they claim it is a sign of evolution’s contingencies. Evolution, they say, can only work with the limited raw materials and designs that are immediately available. It knows not where it goes, and so you have patterns that, while workable, are less than efficient.
But on the other hand, evolutionists also claim ownership of all of biology’s fantastic designs. In fact, evolutionists claim ownership of all of biology, period. That’s right, evolution is supposed to have created everything in the biological world. Walk through any life science library and in the stacks you will see a seemingly endless supply of archived journals covering the seemingly endless list of subjects that comprise the life sciences. All of this is little more than scratching the surface of the biological world. We have learned so much, and yet have so much more to learn.
And according to evolutionists, it all came from evolution. All the DNA, proteins and organelles. All the millions and millions of different species, including all their fantastic and unique designs. All of biology. Though evolutionists do not know how, they are certain these all were the creation of evolution.
Evolution, apparently, is an incredibly imaginative and powerful design and creation tool. It can do it all. And yet, when evolutionists find a pattern, this they say is due to how clumsy their process is. Evolutionists aren’t fooling anyone, they can weave a story for any occasion.
The third problem is that similarities such as the pentadactyl structure in fact do not fit the expected pattern of common descent. In spite of all the textbook propaganda, the empirical evidence is all over the map. There are all kinds of digit patterns, both extant and in the fossil record. As Stephen Jay Gould once admitted, “The conclusion seems inescapable, and an old ‘certainty’ must be starkly reversed.” And as one recent study concluded:
Our phylogenetic results support independent instances of complete limb loss as well as multiple instances of digit and external ear opening loss and re-acquisition. Even more striking, we find strong statistical support for the re-acquisition of a pentadactyl body form from a digit-reduced ancestor. … The results of our study join a nascent body of literature showing strong statistical support for character loss, followed by evolutionary re-acquisition of complex structures associated with a generalized pentadactyl body form.
In other words, morphological patterns in biology, including the pentadactyl structure, do not fit the common descent model. This has evolutionists doing mental gymnastics as limbs and other designs must come and go as needed to make sense of evolution. They are lost, then reevolved, then lost, then whatever. It is all just storytelling.
Finally, the fourth problem is that the argument for why the pentadactyl structure proves evolution is metaphysical. Darwin’s argument, and those before and since are all about evolutionists non scientific premises about how biology should work and be designed. Surely god would never use such a thing as the pentadactyl structure in so many different species.
This, of course, is nothing more than religious rationalism. This silliness opens science up to all manner of argument. Imagine if there were no patterns such as the pentadactyl structure. If the designs were all different and somehow optimized for their respective applications, then evolutionists would point to that as evidence of natural selection choosing the best design. If God created the species, they would argue, wouldn’t we see some pattern? Instead, all we see is adaptation. Why wouldn’t God leave some sign that they were created instead of making the species appear to have evolved by natural processes? Evolution must be true.
It is, in a word, junk science. Religion drives science, and it matters.