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Date Posted: 12:04:25 09/04/13 Wed
Author: Lawrence Barnes
A Revolution In Genetics And Evolutionary Theory Is Under Way
Few people who believe in the concept of the evolution of species according to Darwinian principles realize just how irrational the idea is. Nevertheless, they dismiss creationist and intelligent design rebuttals as ignorant, faith-based efforts to oppose human progress. That amounts to making a double error: first, Darwin was wrong, and second, people who have the wrong reasons for believing Darwin goofed are not atavistic obstructionists -- they are just convinced that they are right, which means their rationale is certainly no worse than that of Darwinians (whom they accuse of being faith-based).
From the first, the fuss over Darwin has been a series of battles in the culture wars that began early in the nineteenth century. The arguments surrounding the very idea of evolution have continued partly because science has never been able to convince everybody that its contentions are credible. After all, demonstrating evolution in experiments is difficult, and when it is possible, it is vulnerable to the criticism that what applies to genetic variations in fruit flies may not apply to humans. The documented emergence of a totally distinct new species, and full accounting for the causes of that phenomenon, remains elusive.
Now a huge change is taking place, for science is discovering that both sides in the evolution battle are wrong. The emergence of a new understanding of genetics bids to correct the nonsense in Darwin's facile speculations, provide new evidence that evolution exists and, for the first time, show that the concept itself actually makes sense.
According to standard Darwinian theory, a mutation begins evolution. This change in the genetic material may be caused by a variety of factors, including radiation; more causes will probably be discovered. It is agreed that all mutations are random, and that the great majority of them are deleterious. The individual with the new DNA may, however, have an advantage over his relatives and neighbors, and if so, natural selection works to benefit his offspring. He produces more babies than everyone else, and his children are better equipped to survive. Differential reproduction is, therefore, the mechanism by which a beneficial mutation spreads. The gene pool is altered, changes in the genetic endowment of the population continue, and eventually, quantitative distinctions impose qualitative ones. The advantaged members of the population can no longer breed with the disadvantaged ones, and a new species has emerged.
If you are unconvinced by Darwin's fantasy, you are at the threshold of truth. The problems with his oversimplification of reality are many, but these stand out:
Mutations typically do more harm than good because most of them are, it is agreed, negative. Therefore only a very few beneficial mutations will exist at any time, and because those are randomly generated, one can reasonably say that in a tribe of, say, five hundred individuals, it would be statistically nearly impossible for two individuals to have the same beneficial mutation.
Therefore one can very seldom posit more than a single individual who is better-adapted, even in a relatively large population. Will he survive? Given what is known about infant mortality rates, it is reasonable to say his chances of survival probably exceed fifty percent; that's not good. Now suppose this individual does in fact thrive, and does produce more offspring than anyone else in the tribe. So...what?
So not much. The chance that very many of the genetically advanced individual's offspring will carry the beneficial mutation could be less than fifty percent (remember, he will be breeding with females who do not have his favorable mutation). So in a population of one hundred, you might now have five people who are genetically better off than everybody else.
How likely is it that these folks are going to be so spectacularly successful, so stunningly sexy, that they will literally reform and reconstruct the gene pool of even this small tribe? This question calls for a statement of the probabilities, and that challenge should daunt even the most resolute Darwinian.
How to think about this? Perhaps Johann S. Bach can help. His musical talent was at least partly, and more likely largely, genetic. It ran in his family. Now suppose for a wild moment that people in Bach's day were so impressed with music that they clamored to have children by or out of his descendants. Does any Darwinian honestly believe that would have somehow enhanced the musical gifts of humanity? Of course not. Bach's genes were diluted as soon as they splashed into the pool. Even if he had had a hundred offspring, and if they had each produced a hundred offspring, the effect on music would have been less than trivial. With each generation, the Bach musical genius was attenuated.
One individual can't make enough difference to account for evolution. Only by escaping into fanciful overgeneralizations can Darwinians suggest otherwise.
Clearly, the best way to get a tribe to evolve is to plant beneficial genes in most of the population, and get everybody busy breeding.
What Darwin proposed, though, was the triumph of a single instance of a single genetic advance over all the vagaries of life. If that favored individual carrying the Next Step in Human Evolution happened to be hit by lightning or poleaxed by a jealous husband, how long would it be before another Next Step came along -- by sheer chance? The answer produces an astronomically large number.
Yet what the fossil record tells scientists, and what they learn from observing what is sometimes called microevolution in the wild, is that evolutionary movement toward better and better adaptation can and often does proceed at a rather regular pace. There are exceptions, and some populations do evolve faster than others because of their organization of sub-groups and the degree of interbreeding and inbreeding, but overall, it seems that the emergence of adaptive characters is a powerful, steady and relentless process. The bones demonstrate that evolution is a fact, and the studies of DNA and the anatomical features of living apes are unequivocal: humans are descended from non-human hominids.
If the current understanding of mutations, natural selection and differential reproduction is wrong, then how can we explain the obvious?
The inheritance of acquired characters is an attempt to correct the understanding of the mechanism of evolution. To put it crudely, you have longhorn cattle, and the horns are a problem for you, so you cut them off, and when mama Bos has baby Bos, the little one is born with no horns. The baby inherited the character (no horns) its ma and pa had acquired. You may recall that this simple-minded twaddle was called Lamarckian genetics and later Lysenkoism. If you are interested, look it up, because there is no point in wasting words on it here; it's rubbish.
Or is it?
Well, an attempt to explain the stunning series of grotesquely improbable events behind speciation can get you into serious trouble. Nevertheless, one of the greatest scientists of the twentieth century, a man you never heard of (unless you read this newsletter), Ludwig von Bertalanffy, speculated that perhaps there is a teleological element involved in evolutionary biology. He believed there is a directionality to evolutionary events, and that means ends -- goals -- are involved.
He was ignored.
At about the same time, another genius of the age, Arthur Koestler, wrote a little book titled The Case of the Midwife Toad. He was laughed at, partly because he was a brilliant novelist and writer of perhaps the most significant political book of his time, Darkness at Noon, and so could have nothing to say on biology and genetics.
Late in their lives, Koestler and von Bertalanffy met and conspired, but the time was not right and their personalities were too fully developed to allow fruitful collaboration. Future historians of science should make note of the event, however. It will prove to have been a dead though predictive branch on a very vigorous tree.
Darwin, Lamarck, Lysenko, von Bertalanffy and Koestler all had one advantage and one failing: they were free to speculate, and they had no solid experimental basis on which to stand. If something is true, it should be demonstrable. That is what science should require of any hypothesis. If Newton's laws are true, they will allow prediction of the movement of bodies in space and time.
As rational and direct as this principle sounds, it is often violated.
Consider, for example, string theory and superstring theory. Neither has any basis whatsoever in empiricism. Both are pure mathematics, and arbitrary at that. Now note Koestler's book on the midwife toad: he documents the experiments conducted by a fellow named Paul Kammerer, who tried to show the inheritance of acquired characters. Kammerer died before he was able to come up with more than a shadowy indication that he was on the right track.
This mention of the past's dead ends leads to the present, and the news is stunning.
Its revolutionary and impressive nature comes from the fact that it is based not on plausible speculations, but on hard empirical evidence. Experiments confirm it. The challenge is not to find evidence for the guesswork, but to find explanations for the facts.
It's called epigenetics, and it states (too) simply that the stresses of the environment and the activities of the organism can and do modify genetic material such that the genotype inherited by the next generation produces a distinctly different and purpose-modified phenotype.
One way of putting it would be to say that if you decide that it is necessary for you to turn from a contemplative existence to a strenuous life of violent physical activity, your children will be somewhat better adapted to athletics. If they in turn are preoccupied with enhancing their endurance and strength, your grandchildren will be better suited to such pursuits than you are.
The implications are sweeping and of tremendous importance to population genetics. They explain how it could be that an entire population -- a tribe, say -- would become, in no more than one hundred years, better hunters or healthier people. Effort and partial success are rewarded by genetic changes that favor adaptation precisely if and when it is needed.
Not all mutations are random. Some are created in response to need, effort, environment, behavior and perhaps -- this is getting spooky -- even mindsets. Culture, man's extrasomatic means of adaptation, can drive his somatic adaptation.
Note that the old puzzle of why some populations seem to settle in, and, having found their environmental niche, stop evolving has just been solved.
It is probable that some will reject epigenetics, mocking it as "new Lysenkoism." Its greatest opponents will be creationists and advocates of intelligent design, who will see at once that it is now evolution, not Darwinism, that is the enemy. That's a correct perception, for thanks to epigenetics, evolution now provides a more rational and therefore more credible account of human origins. Darwin has long been the albatross around the neck of evolutionary theory. Correcting him empirically is immensely significant.
It appears (though this could be an ignorant view) that opposition to epigenetics has yet to emerge in the scientific community. The new data are being published in peer-reviewed journals and the hypotheses are being accepted as worthy of consideration. Epigenetics concepts and findings are joining the mainstream. Of course that may be a hasty judgment, but so far, so good, as Savannah Hensley would say.
A revolution this profound and consequential in genetics and biology is almost unprecedented. Whether epigenetics belongs in the same category as Mendelian genetics (and its partner, the work of Thomas Hunt Morgan), the germ theory of medicine, the invention of the microscope or the discovery of antibiotics is impossible to say, but because it has seismic consequences for anthropology and even philosophy, it has to be considered monumental. Seldom has one concept been so instrumental in explaining so much. Like Newton's laws and Maxwell's equations, this is big -- bigger, possibly, than Einstein's two theories, both of which have provoked disputes over their resulting paradoxes and problems (such as "dark" matter and energy, mentioned in a recent issue of TLB). If epigenetics turns out to be as important as this newsletter believes it will, this generation is witnessing a quiet change in the way all life-forms are to be understood. It does not get more exciting than that!
If you are interested in epigenetics, there are many places on the internet to investigate; do a Google search and proceed.
Puzzled by the reference to Savannah Hensley? See this web page. Savannah is this newsletter's favorite celebrity.
The expected creationist/intelligent design response to epigenetics will be, of course, that adaptive processes neither explain nor produce speciation. Better and better adapted life-forms do not have to change to some new creature that cannot breed with most of its neighbors. Though only a partial truth, that is a credible debating point, so the battle will go on. The death knell of creationism has yet to sound, and this newsletter believes that even if it did, many would say the bell had been hit by a meteorite. When God tells you What Happened, you can't doubt, and research is not just unnecessary, but pointless.
Until very recently, it was thought that the Neanderthaler were a distinct species, which by textbook definition means they were roughly as genetically different from modern man as a horse is from a donkey. Now that is known to be false, for there is conclusive proof that Neanderthaler contributed to the genetic makeup of modern Europeans. That raises the question of who found whom sexy....
Perhaps the biggest relatively new puzzle for evolutionary biology is the little fellow found in Indonesia, homo floresiensis. He is extremely hard to explain, as some of his traits seem to suggest australopithicine origins that are too direct, too recent and too bizarre for his location. No, he's not pathological. We'll just have to wait to see what he was, but it could be that he, like the Neanderthaler, was fully human, and has been mis-named. It is simply not known how great the variability of the phenotype is, consonant with fecundity. Does the fact that your legs are more ape-like than human mean you can't reproduce with homo sapiens?
Related: what makes a species, and are all people the same species? The answers are slow to come and are hedged with all sorts of disclaimers and caveats. That's how the wise authorities respond, for they know that no one has tried to get an Eskimo and a Hottentot to produce children.
If Bach's musical genes interest you, do look for recordings of the works of P. D. Q. Bach. His amazing compositions are too little appreciated.
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