A piece at Evolution News and Views reminds us that for every question science answers it raises a dozen more. Just as we approach what we think will be a complete understanding of the genetic code inscribed in the DNA molecule it turns out that new layers of complexity and mystery come into view. James LeFanu writes of the totally unexpected puzzles researchers are confronting as they study biological inheritance. I've edited the following slightly to make it more clear:
The most obvious of those 'puzzling questions' ... is the 'gene number dilemma' epitomized by the most astonishing revelation of the Human Genome Project: that we have roughly the same number of genes, a modest 20,000, as the millimeter long worm, C.elegans [which] is fashioned from just 1,000 cells (compared to our 60 trillion) and has neither a circulatory system nor internal skeleton and a life expectancy of just two weeks. Every newly sequenced genome has added its own further twist to this surprising lack of any correspondence between gene numbers and organismic complexity. Flies and chickens have a third fewer genes than the diminutive C.elegans while, at the other extreme, plants such as rice and soya bean have twice as many.
The further yet more 'puzzling question' is the revelation of the interchangeability of the master or homeotic genes across diverse species. For example, the same gene that orchestrates the fly's distinctive compound eye does so for the very different mammalian camera-type eye. That interchangeability across species reaches its zenith with the finding that we share 99% of our genes with a mouse. How so trivial a genetic difference can generate such diversity of form defies all explanation, other than to suppose it must be 'something to do' with gene regulation, i.e. 'the turning on and off of genes at different times and places in the course of development.'
The implications are clear enough. Biologists could, in theory, sequence every living creature on the face of the planet, but this would only confirm that they all share the same core set of genes that account for the nuts and bolts of the proteins and enzymes of the cell of which all living things are made. But beyond that the really interesting question, the question of 'form' or what it is that so readily distinguishes the elephant from the octopus, fireflies from foxes, would remain as elusive as ever.
The genetic instructions must be there, of course, because otherwise the tens of millions of our fellow species would not replicate themselves with such fidelity from generation to generation. But we are compelled in the light of these extraordinary findings of the recent past [to conclude] that we have no conception of why we should become so different from a worm or fly.
In other words, neither the number of genes nor the specific structure of the genes seems to account for the differences between very different organisms. So what does?
[T]he myriad of random genetic mutations that would provide a basis for the transformation of one form of life into another are nowhere to be found. "We cannot see in this why we are so different from chimpanzees," observed Svante Paabo, Chairman of the Chimpanzee Genome Project, on its publication in 2005. "Part of the secret is hidden in there, but we don't understand it." Nothing has subsequently emerged to challenge that conclusion.
One gets the impression that despite the vast amount of knowledge we've accumulated since Watson and Crick first elucidated the structure of the DNA molecule some sixty years ago, we've barely broken the surface of what is there to be learned. The complexity and engineering of DNA replication and protein transcription is far greater than we imagined just a decade or so ago. Beneath the structure of the double helix itself is a congeries of regulatory systems, a series of software programs along with the necessary bio-mechanical hardware, that control a myriad of gene functions. These systems tell the gene when to turn on and off, the timing of which has profound consequences for what type of structure will result. They also cause a gene to program for one protein at one time and a different protein at another time. There are yet other systems which cause different genes to work in tandem, in certain situations, to produce a particular effect at a particular moment. Yet other systems patrol the double helix repairing breaks and other damage. It's all so complex that had a human being developed it we would think him to possess perhaps the most brilliant mind ever to appear on the planet.
Even so, our materialist friends insist, one should resist with all one's might the temptation to think that it's beyond the power of chance and physics to account for this breath-taking complexity and organization. We must have faith that such intricate, astonishing, and multi-layered precision could have evolved purely by accident given billions of years of time, just as given enough time Windows XP and the PCs to run it could have been produced by a random symbol generator along with the laws of chance and physics. It sounds hard to believe, the materialist acknowledges in his more reflective moments, in fact to the layman it sounds miraculous, but it just must have happened. Why? Because the alternative - that a mind was somehow involved - is just, well, too d�class�, too religious, to be seriously entertained by such sophisticated and intelligent people as ourselves.
RLC
