by Keith Morrison
©2009 Keith Morrison
A century and a half ago, a book was published that changed everything.
Written by the son of a wealthy doctor and financier, coincidentally born 200 years ago in February, 1809, this book was the culmination of 23 years of thinking and study, the follow-up to the original five year mission to explore strange new places and to seek out new life. The author was 22 years old when he started out on that voyage; over the next 27 years, he eventually realized and understood, however imperfectly and limited by the existing knowledge of his day, one of the basic principles of life. It would take the experiments of an Austrian monk named Gregor Mendel to help explain the why, and a century later James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins would be the ones to reveal the structure of the how, but two sentences from that book were some of the most important things ever written in any language:
As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.
The book was, of course, On the Origin of Species by Means of Natural Selection, or The Preservation of Favoured Races in the Struggle for Life by Charles Robert Darwin.
Darwins genius was in seeing the obvious and stating it. To be fair to his peers, the germ of the idea had previously been expressed by others as far back as Aristotle; Origin of Species itself was printed as a result of Alfred Russel Wallace publishing a paper that discussed the concept of natural selection, with Darwin writing his book to establish his precedence in the idea. But while other people may have toyed with conjectures about the transformation of life, Darwin was the first guy to put all the pieces together and build an airtight case for how it actually worked. Did a pretty damned good job of it, too: Unlike the later work of Einstein, or that of earlier scientific giants like Newton, you didnt need to know the esoterica of mathematics or some other theory required to understand his theoryyou only needed the ability to see and a modicum of common sense. And really, theres nothing complicated at all, or even very arguable, about natural selection. And we can look around and, despite the adamant denials of some, we can see it happening. Natural selection, or to be more general, the Theory of Evolution through natural selection, is the very heart of modern biology. Without it, nothing in biology makes much sense; with it, everything does.
(At this point, I am required by the rules on discussing this topic to point out that the mere fact of its being named the Theory of Evolution does not mean its hypothetical, any more than the so-called Theory of Gravity means the idea that things fall down is up for debate; evolution, like gravity, is an observable fact. Like the Theory of Gravity, the Theory of Evolution is the explanation for the how.)
Anyway, Darwins theory made a real mess of some long-cherished notions about how spiffy human beings are. Some people didnt like that changeand still dontwhich is why, of all scientific theories, evolutions position in the public consciousness is uniquely, and groundlessly, precarious. Deny that E=MC2, and people will look at you oddly; claim that Atomic Theory is out to lunch, theyll consider you a crank; deny gravity exists, theyll call you a nutjob. But if you deny that evolution is real? You, too, can be on the (generally Republican, these days) Presidential/Vice-Presidential ticket; have your own highly lucrative Sunday morning TV industry; or get invited to air your views on news programs with talking heads who listen and nod gravely as you spout off the most insane bullshit.
Darwin didnt know everything, of course; it took the Modern Synthesis in the early 20th Century to get a truer understanding of evolution and how it worked, and even now there are some controversies. Goulds and Eldredges theory of Punctuated Equilibrium, the importance of group selection versus individual selection, even basic questions such as whether or not humans are still evolving. Evolutionary biologists dont know everything, and new surprises which challenge the details of the theory are not only expected, they are eagerly anticipated. As someone once said, some of a scientists favorite words are Huh thats weird.
In light of the aforementioned anniversary, I thought Id recap some of the little bits about evolution that writers in this genre tend to how to put this gently make a complete and utter wreck of. I did this once before, a few years back, so feel free to skip the refresher.
First off, there is no fixed endpointno march ever-upward to some species destined to rule the universeno plan. Evolution simply doesnt care whats going to happen next year, let alone a million years from now. And thats why the machine that force-evolves someone into the next stage of humanity or whatever (a staple of comics and bad science fiction) is a crock. Sure, if youre talking about an environment with a particular set of environmental conditions, you might be able to predict what humans in that environment could evolve towards but such a prediction is only good for humans who are in that particular environment. And even then, randomness can toss you a curve ball.
Take, for example, my eyes: Theyre blue. If aliens came to Earth 15,000 years ago and predicted what Future Human (i.e., us) would look like, Im pretty confident my eye-color would not be one of the features included in said aliens prediction. Fifteen thousand years ago, no Homo sapiens had blue eyes; we know this because of recent research indicating that blue eyes are the result of a one-time chance mutation around 10,000 years ago, which (for whatever reason) quickly spread among part of the human population. It might have had some kind of adaptive value in the European ice agehuskies and other northern dogs are noted for bright blue eyesor it might simply have been because other humans thought they were hot and sexy. Whatever the reason, that one-off event is not something that could have been predicted.
Another example from my mutant genome: I can drink milk as an adult. The mutations that allow for that are more widespread (and different: the European one is different from the Central Asian one), but such a mutation only provides survival value if you are a herder of a certain mammals. And theres not much evidence that the humans of 15,000 years ago were herders.
The bottom line is, theres no way someone taking some of my ancestors 15,000 years agowho, incidentally, are also your ancestorscould have sped up evolution and produced someone who looked like me, in at least two ways.
This is also, as I explained before, why that whole devolve and then re-evolve into an existing animal business is garbage. Suppose you go back to the youngest common ancestor of me and, say, a dog, a neat trick that could take you as far back as the Jurassic. Theres no way that small dinosaur snack could have been predicted to produce a dog or a human, or any of our assorted relatives.
More importantly, and also a result of evolution, devolving makes no sense because while you might end up something that resembles one of its ancestors, the series of changes that have taken place since then might very well mean there are significant differences between the modern devolved critter and its ancestral original model.
Example: Land animals, as everyone isor should beaware, evolved from fish. Some of those animals have returned to an aquatic lifestyle, and some look sort of like fish, but the differences are dramatic. For one thing, the reptiles (modern and prehistoric), mammals, and birds that live in the ocean dont have gills. Many dont move the same way as fish, either: Whales flex their bodies up and down instead of side to side, penguins and sea turtles and sea lions fly with their arms, plesiosaurs propel themselves with all four of their limbs, and so on and so forth. The modern animals have devolved, in a loose sense, but they dont look particularly like Tiktaalik. And thats only in gross physiology. Get into the inner workings and you get into a real bind, with biochemical pathways and processes having likely changed.
Theres no excuse for a writer who touches on evolution to get the basics wrong. There are enough books that have been written for the general audience to be able to get it right.
This is the stuff were made of, the place we came from, and whats brought us the world we live in. It is the story of life in all its glory and drama and beauty.