Let's get something straight: despite what you may be hearing from Kansas, evolution is a fact, not a theory.
Gravity is a fact. If gravity
wasn't a fact, we'd know about it pretty damn quick - people, cars, patio furniture and so on detaching themselves from the ground and floating up into space would be a bit of a giveaway, I think. But there are several
theories of gravity. Theories don't dispute the facts - a theory is an idea about the underlying causes that explains the facts. In this case, one theory is that all the atoms that make up matter emit particles called Gravitons that carry the gravitational force. The more matter, the more particles, and therefore more gravity. The Earth contains so much matter, six thousand million million tonnes of it, that the gravity it generates is pretty strong.
The graviton theory is just one of several theories about what makes gravity work. At most one theory can be the right one but they're all
good theories - that is, they explain the facts and we can design experiments to test theories against observations. If an experiment shows a result that is not what the theory predicts, then that theory is wrong. We may need to make modifications to the theory, or discard it altogether in favour of another theory. What's important, in scientific terms, is that any good theory is
falsifiable - that is, that it's possible to design an experiment that could prove the theory wrong.
Now this is important: while it's easy to break a theory by performing an experiment that proves it wrong, it is
not usually possible to prove that any theory is correct. When an experiment shows the result that the theory would predict, that result supports the theory but does not prove it. In fact, the result of the experiment may be as predicted by several competing and incompatible theories (including theories that haven't been thought up yet); in that case the result of the experiment supports all those theories but doesn't prove any of them correct.
For the everyday we don't need to know exactly how something works to be able to make use of it. We know enough about gravity to be able to weigh things and predict the motion of comets and asteroids, for example, even though we don't know for sure which of the available theories is closest to the truth. We don't fully understand quantum physics but we know that it's real and we know enough about it to be able to create television and computers and lasers. We don't fully understand light but we know it's real (or you wouldn't be reading this) and we know enough about how it interacts with matter so that we can make solar cells and telescopes.
Evolution is real; we see it all the time. It happens slowly, so that we don't usually notice it, but over decades and centuries it becomes more and more apparent. The usual example that schoolkids are given (at least, this is one that my biology teacher taught many many many years ago) is a species of moth found in northern England. At the beginning of the eighteenth century most of these moths were light grey, a natural camouflage that made them difficult to see against the light-coloured bark of the trees they landed on. In the middle of the century the Industrial Revolution came to town and with it, the soot of ten thousand coal-burning factories covered the bark of the trees of the region. By the end of the century the moths were predominantly dark, so that moths were still camouflaged against the soot-blackened bark of the trees. The species had evolved - adapted to the changing conditions of its environment. That's just one simple example but there are countless others.
Evolution is a fact, as undeniable as light and gravitation and the quantum.
There have been a number of theories to explain how evolution works but by far the most successful is the one that began with the ideas of Charles Darwin - the theory commonly called
Natural Selection, or Survival of the Fittest.
I'm not going into detail about it here because that's not the point. I will say, though, that I
thought I understood the theory but I didn't really, as well as I should have. The whole thing became far more clear - and elegant, and beautiful - after reading Richard Dawkins' book
The Blind Watchmaker, which I can't recommend highly enough. If you haven't read this book, you should.
Natural Selection may be "just a theory" but it's a damn good one; it explains the existence and diversity of life on this planet better than any other theory currently available. It's testable and falsifiable, and over three hundred years of challenges and tests have not shown it to be wrong. Other theories, such as Lamarckism, were proved wrong a long time ago.
Now we have something else. It's called Creationism and basically it says that the Biblical account of the creation of life is literally the one and only true explanation. In an attempt to make it scientifically acceptable creationism has... well,
evolved, into "Scientific Creationism" and more recently "Intelligent Design", or "ID". Its proponents are trying to convince school boards and others that it is as scientific a theory as Natural Selection, but it isn't; ID is
not a scientific theory. The very nature of ID is such that there is no experiment that can be devised that would prove it wrong; in essence,
everything becomes evidence that supports ID.
For example, ID proposes that the Earth was created by an intelligent power (read, "God") about six thousand years ago. When presented with fossils and carbon-dated samples that can be proved older than that, a truly scientific theory would crumble, but not ID; to get around this minor wrinkle, ID'ers say that the intelligent power deliberately faked the old rocks and fossils to test faith. Why an intelligent power would deliberately set juvenile traps like this is not explained, but the point is that it doesn't matter what evidence is presented, ID always has some way to "explain" the inconvenient facts.
Having failed in the past to persuade the school boards that ID is a valid scientific theory, its proponents have resorted to dirty tricks such as getting their supporters voted onto those same school boards so that they can rewrite the rules. Now, in Kansas, they're trying to not only rewrite the rules but change the very definition of
what science is so that they can have their ideas taught to children as if they were as valid and scientific as Natural Selection. The children, who don't have the skills to tell truth from junk, will end up believing the ID doctrine and most of them will carry those beliefs through to adulthood.
In an scientifically advanced country this is a scandal. The problem is that, as scientifically advanced as this country is, individual citizens have for the most part not been educated in science well enough to tell the difference between real science and pseudoscientific claptrap. As a result, the legislators and parents (and in many cases the teachers, sadly) are just not able to tell the ID crowd where to shove their doctrine.
The ID'ers have a right to their beliefs. What they do
not have a right to is to demand that those beliefs are taught as scientific fact in science classes. These teachings should be kept in religious classes, where they belong.
Labels: Politics, Rants, Science
