Darwin Turns 200

Darwin’s “Origin of Species” marks the origin of modern science.

Charles Darwin didn’t free the slaves or stop the South from seceding, and for obvious reasons, modern presidents do not compare themselves to him the way they do with Abraham Lincoln. But during his life, he established himself as one of the most important and best scientists of all history. His theory of evolution was not only revolutionary, but also turned out to be pretty much correct – a rare feat that rightfully puts him in the company of scientists like Einstein and Newton. Oddly enough, one of Darwin’s earliest influences wasn’t some frothing atheist, but rather the British theologian William Paley. Paley is famous for the so-called “watchmaker argument,” an argument for God’s existence which was irrefutable until Darwin came along; if you find a watch lying around, you conclude that there was a watchmaker who placed it there, since watches are complex and do not form by random chance. Likewise, nature is complex; organisms are complex and they occupy specific roles in complicated ecosystems, so there was a designer ordaining these things. Darwin noticed that nature didn’t reflect this idea. Organisms aren’t placed neatly into their environments. They squabble and fight, killing each other and driving each other into starvation. In short, they compete, and the ones that are better able to compete survive and reproduce. Just as a breeder selects which of his animals will reproduce according to his own exacting standards, nature unconsciously selects organisms which meet the demands of their environment. This process, appropriately termed “natural selection,” is anything but random chance. “Chance or design?” is a false dichotomy; natural selection is a third option. Darwin’s idea was just plain better than the creationist ideas of his time. Assimilating data from comparative morphology, ecology, the fossil record and geology, he proposed that all organisms are related in a great “tree of life” and that natural selection is one of the mechanisms that accounts for the process of evolution. Over the past 150 years, just about every observation in biology has confirmed this idea. And lest anyone doubt the usefulness of Darwin’s theory, quite a bit of modern science depends on it. We all know that pathogens mutate and this year’s vaccine or antibiotic may be useless next year due to natural selection. But one unsung triumph of evolution is in the testing of drugs on model organisms. To estimate their effects on human subjects, biologists and doctors test chemicals or protocols in rats, flies or other animals. Evolutionary assumptions always underlie such tests. If evolution is not true, then there is no good reason to think that, say, a rat and a human will have similar biochemistry – so a drug’s success in a rat shouldn’t be a good indicator of success in a human. After all, a creator could have put these animals together independently, mixing and matching whatever parts, genes, and proteins he wanted. Evolution is much more constrained in its design process. Evolution is even used by engineers and computer scientists to find solutions to difficult problems, such as the design of circuits. In fact, natural selection can even be used to design watches – just search YouTube for “proof evolution is a blind watchmaker.” Like real evolution, so-called “genetic algorithms” seldom yield perfect solutions, but they are often better than human-designed solutions. Biology, without Darwin, might best be described as a “stamp collection” or an assortment of essentially unrelated facts. Developmental biology, ecology, genetics, molecular biology and taxonomy might well be separate, isolated disciplines were it not for the presence of a theory which unites and accounts for them. Darwin’s “On the Origin of Species” was basically the origin of modern biology. But this shouldn’t be taken to mean that Darwin was never wrong. He predicted that many fossils would be found which would change the gap-filled fossil record into a continuum documenting every kind of complex organism that has lived on Earth. “Transitional” fossils such as Archaeopteryx, a feathered, bird-like reptile, have been found, but the fossil record remains somewhat splotchy. He believed, like French naturalist Jean-Baptiste Lamarck, that organisms passed on traits acquired during their lifetimes to their offspring; today, we know that organisms pass on traits through a molecule called DNA, which operates in a simpler manner. He was, like Lincoln, a racist – although, like Lincoln, he was very progressive for the standards of his time and, like Lincoln, his work laid further foundations for ideas concerning the equality of all mankind. He knew less about genetics, molecular biology, embryology and biochemistry than many modern high school students do. But even as biology has developed, it hasn’t produced a single observation that contradicts the essential tenets of Darwin’s theory. Not one. Evolution itself, like any good theory, has evolved, but it is the only explanation for the diversity of life on earth that makes predictions (intelligent design does not) which are correct (creationist predictions are not). Indeed, as a result of Darwin’s work, the phrase “evolutionary biology” is somewhat redundant. All biology is now “evolutionary” in some way. And all biologists owe Darwin a 200-year debt, not only for the example he set as a scientist but for the stunning insights he had into the way life works. Happy birthday, Charlie! This column, accessed via UWire, was originally published in the University of Arizona Daily Wildcat. Please send comments to [email protected]