A previous post raised the issue of pre-adaptation in evolution. The idea remains controversial, but if it is true, it could point to a design or plan built into the DNA of all living things from the outset. In his book The Science of God, Gerald L. Schroeder makes a case for pre-adaptation, which I've excerpted below.
Schroeder is an interesting figure - a trained scientist who tries to reconcile modern scientific data with the Bible. Since I view the Bible as a compendium of myth, legend, poetry, fiction, and a dash of history, I'm not particularly sympathetic to this project. I don't much care if the Bible can be made to seem scientifically prescient, any more than I care about seeing the Epic of Gilgamesh reinterpreted as a forecast of quantum mechanics. Nevertheless, I find Schroeder's books fascinating because he thinks outside the box of materialism and explores concepts like an information-based cosmos (see his book The Hidden Face of God).
In this excerpt, Schroeder considers the implications of the Cambrian Explosion - the sudden worldwide emergence of advanced life forms from very primitive antecedents circa 530 million years ago. How, he asks, did simple protozoans and sponge-like creatures become complex, articulated, lobster-like trilobites virtually overnight?
Over three billion years spanned the gap between the immediate appearance of one-celled life on the just-cooled Earth, 3.8 billion years ago, and the explosion of multicellular life 530 million years ago. Perhaps during those eons, random mutations in the one-celled antecedents of all modern life stored genetic material containing latent (neutral) information potentially useful for the impending explosion of animal complexity. This would then be available for expression suddenly and simultaneously at the inception of multicellular life. Species of modern algae and protozoans have the space in their DNA for this neutral information. Each of their cells contains as much as one hundred times more DNA than a cell of any mammal, including humans. Since micro-fossils of primordial algae and protozoans have shape and size similar to modern specimens, it may be inferred that their genetic library was equally large.
We know that the genetic material of many plants and animals contains blocks of latent information able to be immediately expressed by changes in the environment or by single mutations. Chickens are known to grow hair, not feathers. Horses are born with multiple digits. Human babies unfortunately at times emerge from the womb with their "gill slits" still open. Both mammals and birds produce gill arches during embryo development, but then both mammals and birds, according to the fossil record, share a common origin as primitive fish. Marsh plants when submerged in water develop a leaf structure different from that of the same plant grown on dry land, even when cloned and therefore genetically identical.
According to the "latent library" theory, all this information is quietly present in the genome, waiting for the cue to be expressed. When the marine lizard ichythosaurus appears suddenly in the fossil record with an outer shape essentially that of a fish, or a land mammal becomes fish-like in shape as the arise for the whale, we may be witnessing a stored shift of preexisting genes from latent to active states. Fossils of what appear to be ancient primitive whales having small vestigial hind legs have been found in India and Pakistan. If the fossil record is correct, the phylum Chordata, of which both lizard and mammal are members, has at its base primitive fish. Some fish-like genes are certainly held in the genomes of modern land-based chordates, hence the occasional gill slits of human babies and the gill arches and yolk sacs of mammal embryos. Reorganization and expression of stored genes could account for a rapid "evolution" of the fish-like characteristics of these species....
The obvious questions with regard to algal and protozoan genome size are: why does an algal cell or an amoeba retain so much genetic capacity? And why, within this huge genetic library space, would a primordial protozoan have stored information related, for example, to jointed limbs or vertebrae? There would be no immediate benefit to the amoeba and so no genetic reason for them to maintain this neutral information in their DNA. If it were not neutral, then its expression was clearly not in the forms as expressed in the Cambrian animals.
The concept of a latent library posits a mechanism very different from the classical theory of evolution wherein random mutations provide changes in morphology. Nonetheless, primordial preprogramming of life's developments is exemplified in the morphogenesis of the eye. A gene group, Pax-6, is a key regulator in the development of eyes in all vertebrates. Its analog (a very similar gene) has been found to control development of the visual systems of mollusks, insects, flatworms, and nemerteans (ribbon worms). These represent five of the six phyla that have visual systems. (The sixth phyla with vision has not yet been studied.) The molecular similarity among these analogs is nothing less than astounding. The paired domain of the gene contains 130 amino acids. The match of these amino acids between insects and humans is 94 percent! Between zebra fish and human the match is 97 percent.
Could five genetically separate phyla have evolved these similar genes individually by chance?... The likelihood that random mutations would produce the same combination five times is 10 [to the power of 170] raised to the fifth power.
There is no way this same gene could have evolved independently in each of the five phyla -- it must have been present in a common ancestor. The gene that controls the development of eyes was programmed into life at at a level below the Cambrian. That level is either the amorphous sponge-like Ediacarans or one-celled protozoa. But neither has eyes.
[pp. 90-92, The Science of God, Gerald L. Schroeder]
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