Evolution is a Basic Principle

Evolution is a Basic Principle

Creationists generally talk of the “theory of evolution”. Many who disagree with creationism reply that evolution is no such thing, but a fact. Thereby they fall into the same dogmatism as certain of their opponents, and become subject to the same refutation. After all, what is a fact? Nobody alive has ever met an Australopithecus or watched prokaryotic cells develop in the pre-Cambrian seas. It is a rather feeble retort that nobody has met Adam and Eve either, or watched the world coming into being by fiat.

In the last analysis, those of us who accept the idea of evolution do so because it is an inference, based on many different accumulated observations, which enables us to account for those data, fit them into a scheme that makes sense. The creationist can quite legitimately reply that this is what his beliefs do for him.

However, at this point in the history of science, it is a mistake to agree that evolution is a mere “theory”. That concedes more to the creationist than he deserves.

What is a theory, anyway? To answer that question, we must take a look at the scientific method itself.

Now, a number of distinguished scientists have denied that there is any such thing, and I rather agree with them. That, though, would take us too fat afield now. Let us just glance at the traditional paradigm, oversimplified though it is, the purpose will only be to make clear what we mean by certain words.

In this paradigm, scientists begin by making observations of nature, as exact as possible. Then somebody formulates a scheme which summarizes those observations, preferably in mathematical terms. That is because mathematics is the language par excellence of precision. Somebody else takes such a description and tries to explain it by a hypothesis. That is, this person proposes the existence of a mechanism or a relationship which would logically produce the observations themselves. A good hypothesis also yields predictions; it tells us what further observations we should try to make. If we make them, and the results fit the scheme well enough, then in due course the hypothesis gains the status of a theory. That is, we accept it as depicting, more or less correctly, some aspect of reality.

Evolution is no longer a mere theory. Illustration by Elena.

Later discoveries may prove irreconcilable with the theory. In that case, we have to discard it – or, at least, drastically modify it – and look for another.

The standard example comes from planetary astronomy. For untold millenia, observers had been gathering data about the motions of the heavenly bodies across the sky. This effort culminated, for the time being, in the magnificent work of Tycho Brahe in the 16th century. Meanwhile, of course, there had been many attempts to account for the data. The idea that everything revolves around Earth grew increasingly unlikely as information accumulated; the picture had to be made too complicated, with epicycles. As early as the 13th century, Alfonso X, king of Leon and Castile, remarked that if he had been present at the Creation, he could have given the Creator some good advice.

Eventually Nicholas Copernicus offered a much more satisfactory description, in which the sun was at the center. Galileo Galilei and others refined this system and added to it. Finally Johannes Kepler put it into elegant mathematical form, in his three laws of planetary motion.

Isaac Newton then accounted for those laws by his hypothesis of universal gravitation (even though he himself denied making hypothesis) together with his own three laws of the motion of all bodies, not just planets. Soon observation confirmed this so well that it became a basic theory in physics. By means of it, later generations discovered new planets and explained the behavior of distant stars.

There remained a few loose ends, such as a slow change in the orbit of Mercury. Early in the 20th century, Albert Einstein proposed a whole new theory, general relativity, which included Newtonian mechanics as a special case, and which accounted for those anomalous phenomena.

Thus far the usual description of science in action. As said, it is much oversimplified, and in many instances is scarcely true at all. Still, if nothing else, it does help us give clear meaning to our words.

The important point here, though, is that even taken as face value it is incomplete. It omits a further stage of thought which is of primary importance.

Before going on to that, let us very sketchily review the history of the evolutionary concept. That way we can compare it to the development of astronomy. If nothing else, we will be reminding ourselves that the idea of evolution was not invented by a few subversives in the 19th century, but has a long and honorable pas of its own.

By 1800 the concept was already in the air. There had been some speculation along those lines as far back as Classical times, if not before. During the Renaissance and after, men gradually realized that they were coming upon the petrified bones of beasts which no longer existed. Early in the 19th century, the great French naturalist Georges Cuvier advanced the hypothesis that more than one creation had occurred in the past: that life had appeared several times, to be wiped out by worldwide catastrophes, and that the account in the Bible refers only to the latest of these eras. Regardless of this deferral to religion, Cuvier was considered blasphemous by many. Once some of his students decided to throw a healthy scare into him. One of them costumed himself like the traditional Satan, entered the professor's home at night, woke him, and roared, “ I am the Devil, and for your impiety I have come to eat you!” Cuvier looked him up and down and replied scornfully, :Hmf! Horns and hoofs. You can't. You're graminivorous.”

His catastrophism was denied by a contemporary compatriot, Jean Baptiste Lamarck. A war here at age sixteen, Lamarck later boldly maintained that living species, had developed from less specialized ancestors. However, he thought that the causes lay in environment and the actions of individual organisms. This was so unconvincing that few accepted it until the 20th century, when for a time a version of it became official dogma in the Soviet Union.

(By Poul Anderson).

Evolution has become just such a basic principle. It is as much a fundamental of the universe, as we conceive the universe to be, as are the laws of thermodynamics or relativity. There is no scientific argument against it, only antiscientific one. Illustration by Elena.