According to Darwinian evolution, which is a unguided, unplanned process of random variation and natural selection. Evolution should not repeat itself, in other words you can’t replay the tape of life. Yet the observable evidence from nature contradicts this Darwinian thesis. Similar and unrelated forms are replete in nature. Is an “unguided, unplanned process of random variation and natural selection” a better explanation for this observation or is this the product of reuse by intelligent design?
Some Darwinians have tried to explain this common design as analogous forms in morphology; there are no real common design at the molecular level. In this essay are examples of molecular common design. For this post I would like to expound on one of the examples in the essay, “Convergent evolution in primates and an insectivore”. Before I begin let me include a couple of more related articles here and here.
The essay quotes from a study that shows the independent evolution (convergence) of the protein apolipoprotein(a). Apo(a) and apoB-100 are disulfide-linked forming the main constituents of lipoprotein(a) (lp(a)). This protein is only found in limited species of mammals, the primates and insectivore. [old world monkey (like the baboon), apes, humans and hedgehogs] Interestingly the hedgehog is considered to be our most distant mammalian relative. Our alleged ancestors have diverged about 90 mya.
The Darwinian explanation for the convergence of apo(a) is through the duplication of the homologous gene plasminogen, and then modified the duplicate allele to the same function as apo(a). In other words, the hedgehog at some point in its’ evolutionary past through, an unguided, unplanned process of random variation and natural selection, duplicated the same gene as the primates did at a different time in its’ past through, an unguided, unplanned process of random variation and natural selection. After the duplicated gene these respective species proceeded to modified this allele through, an unguided, unplanned process of random variation and natural selection, to perform the same function and to similar protein molecular sequences.
How much of a coincidence is this putative convergence? Apo(a) is a large protein almost 3kbp. A comparison between the hedgehog and human apo(a) shows approximately a 50% identity. A rough estimate of the probability of deriving the common sequence of 50% identity is 201434 = 4.75 X 101865. There are 20 different possible amino acids used in biological systems. For a protein to converge to an identity of 1434 amino acids similarities from a total of 2868 protein length is roughly 4 followed by 1,865 zeros. Is it reasonable to assume a Darwinian explanation or is it beyond credulity? ID is the only explanation that can overcome these probabilities. Common design is the only reasonable explanation for such molecular similarities.