What is the Theory of Evolution?
Photo by Miriam Miles on Unsplash
The Darwin Story
In 1831, the English ship HMS Beagle set out to survey the coast of Patagonia and the Tierra Del Fuego off the top of South America, before circumnavigating the world. On board was a 22-year-old naturalist named Charles Darwin, and he was in for an adventure. During the five years it took to sail around the world, Darwin spent a year and a half aboard the ship. The rest of the time, he was off exploring and learning about the flora, fauna, and geology of South America. He collected huge fossils of extinct animals. He fought in battles, survived earthquakes, climbed mountains, and pretty much had a manly expedition.
Over the course of the trip, Darwin wrote a 770-page journal and collected 5,436 specimens of bones, skins, and carcasses, which surely produced a lovely odor on the Beagle. On the way back to England, they stopped at the Galapagos Islands, where Darwin observed iguanas, tortoises, and finches.
Darwin returned to England and became a respected geologist. While studying his journals and collections of fossils and specimens, he came to the conclusion that all creatures must have descended from a common ancestor, and are all connected in a great branching tree of life. This contradicted the accepted theory of the day, which said that all life was created at once and that animals do not change or adapt over time.
After reading Thomas Malthus' writings about the struggle between people for limited resources, Darwin applied the principle of competition to the natural world, theorizing that creatures which are better adapted have greater access to the resources of the environment. He called this idea "natural selection." He didn't publish his controversial theory right away. Darwin married, moved to the country, and became something of a recluse (a very wealthy recluse; he was a landlord of large estates and invested in railroads).
Over the years, England mellowed toward new ideas, and Darwin began to feel more comfortable about publishing his theory of evolution. He began work on his book The Origin of Species by Means of Natural Selection (a catchy title). In June of 1858, Darwin received a letter from Alfred Russel Wallace, letting him know that Wallace was about to publish his own theory of evolution. They agreed to go public together, and they both had papers read at the Linnean Society on July 1, 1858.
On the Origin of Species was published in November 1859, but since Darwin was often too ill to speak in public (and he hated debates), his friend Thomas Henry Huxley was the public face of the theory, speaking all over England and writing about evolution. The theory ignited a debate about humanity's place in the creation that continues to this day. Darwin, after years of ill health, died of a heart attack on April 19, 1882 and was buried at Westminster Abbey, even though he was an agnostic (this info is from Encyclopedia Britannica).
Darwin and the Monkey Men
“We thus learn that man is descended from a hairy, tailed quadruped, probably arboreal in its habits, and an inhabitant of the Old World.”
Charles Darwin (The Descent of Man, 1871)
The theory of evolution that made Darwin famous was a radical departure from the most common origins theory of his day. That theory said that God created the Earth and everything on it, pretty much in their complete and current form, as described in the first three chapters of Genesis, perhaps within the past several thousand years. Instead, the theory of evolution claimed that the Earth is millions of years old (at least), and that all the species in the world likely evolved from one ancestor, a one-celled creature that somehow appeared in the primordial soup of the ancient Earth.
The process of natural selection is based on a couple of ideas: the first, as mentioned above, is that of competition. There is only so much of each resource (food, space, mates, etc.) in a given environment, so all living things constantly compete for their share of the stuff they need. The second idea is that of variation. At the time Darwin's ideas were going public, Friar Gregor Mendel was demonstrating that creatures' genes help determine their features, and often their behaviors. In each generation, the combinations of these genes vary slightly (because of parental contributions and random mutations), producing slightly different bodies and activities.
Though Darwin didn’t know about genes, he combined the ideas of competition and variation to come up with the "survival of the fittest," the theory that in each generation, more of those best suited for survival live long enough to pass on their traits to the next generation. This process doesn't happen all at once; it typically takes many generations for the more fit to out-produce the less fit. But, if the Earth is millions of years old, there would be enough time for the incredible variety of species that we observe today to develop from one. Natural selection is the process of the advantaged creatures surviving to reproduce.
The theory of natural selection explains why finches that Darwin observed on the Galapagos Islands developed different beaks to fill different niches in the environment of each island. Since the competition for resources favors the resourceful, evolution should result in a high degree of specialization, and that is just what we see in the animal and plant kingdoms. Consider the anteater's long, sticky tongue or the Venus fly trap's animal-like reflexes. Creatures like these fill very specific roles in their environments, and that has enabled them to thrive.
Another part of the theory of evolution is sexual selection. This is the idea that some animals develop features solely for the purpose of attracting and impressing mates, like the antlers of moose, the manes of lions, or the six-pack abs of humans. This kind of evolution can result in drastic extremes, such as the peacock's tail. There is an evolutionary advantage to being a successful sexual partner, or at least an attractive mate.
The Controversy
Darwin's ideas were met with some skepticism and much outright hostility. Many who believed in the Bible as the perfect Word of God saw the theory of evolution as a blasphemous contradiction to its truth. And even those who didn't were disturbed by the possibility that humans are nothing more than especially successful apes. It felt to some like trivializing the human experience to think that our actions, thoughts, and emotions are nothing more than survival mechanisms. And the blind process of evolution made all of life appear to be a purposeless accident. We live to pass on our genes to the next generation; but why should we care about future generations - people we'll never meet and who cannot improve our lives in any way? Many saw Darwin's ideas as dangerous, and many do today.
Evolution seemed to some like an effort to write God out of the pages of history and replace Him with a soulless process, rendering life essentially meaningless. Today, a large percentage of Americans reject the theory of evolution. For example, Australian Ken Ham is a popular Christian speaker and founder of the organization Answers in Genesis, which built the Creation Museum and Ark Encounter, museums in Kentucky that promote the beliefs that Earth is only a few thousand years old, the theory of evolution is a lie, and dinosaurs roamed the Earth in human times.
Christians like Ken Ham take the Bible seriously and honestly care about reconciling the strange paradox of the human creature: we are so similar to the animals in our bodies, and yet so different in our intellect, emotions, creativity, and culture. The theory of evolution brought the similarities to the forefront, and there has been a strong reaction among Christians to emphasize the differences.
The theory of evolution also elicited a strong negative reaction from Christians simply because it elicited a strong positive reaction from Atheists.
"Although Atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled Atheist."
Richard Dawkins, The Blind Watchmaker (1986)
Atheists use natural selection to explain why creation doesn’t need God. They say that since cold reasonless processes can account for the diversity of living things, life is not a miracle but an accident.
It’s hard to imagine what it must have been like for an Atheist in the days before Darwin; to declare that God does not exist, but to have no other viable explanation for life or story of creation. Because Atheists latched onto the theory of evolution so enthusiastically, many Christians of the day assumed it to be the antithesis of their faith and rejected it without even considering the evidence and implications. This reaction is understandable; they felt that their core beliefs were under attack.
There were others, though, such as Asa Gray, the American botanist, evangelical Christian, and friend of Darwin, who didn’t see the theory as a threat to his faith – at least as long as evolution was seen as a limited explanation for certain biological questions, and not as a total theory of purpose and meaning. And in general, Catholics were less skeptical of the theory than Protestants.
Proliferation in Science and Culture
Despite the controversy, the theory of evolution and its implications have proliferated in the sciences and the culture at large. It began, of course, with general biology. But now there are other evolutionary sciences, which seek to understand humanity through the lens of adaptation and survival. It’s clear that, whatever else humans are, were are very good at adapting and surviving; there are now over seven billion of us, and we're living in and exploring every corner of our planet and even off of it (as in, outer space).
The majority of scientists are convinced that the theory of evolution is correct, because it does a good job of accounting for many phenomena, such as the great diversity and similarity of life; the fossil record; genetic diversity within each species; the niche method of survival that results in very specialized animals; and vestigial organs, like the useless legs of some lizards, the tiny wings of kiwis, or the brains of politicians.
Ken Ham and others have made the case that the theory of evolution has serious gaps, due especially to missing fossil links between very different species that appear to be genetically related. Others, like Intelligent Design proponent Stephen C. Meyer, aruge that the theory of evolution can’t explain events like the Cambrian Explosion, a huge proliferation of new species that happened 530 million years ago for reasons not yet understood. And of course, scientists have yet to explain how life came to exist in the first place, so they don't know why natural selection has any material on which to work.
Evolution has worked its way into other disciplines as well. An ugly example is Eugenics, a movement that was popular in the days before World War II. Proponents said that humans are not letting natural selection take its course and are instead helping the weak to survive and reproduce (the handicapped, "inferior" races, the poor, etc.), so we are “weakening” our own species. They said humans need to perform unnatural selection by removing these people from the gene pool, often by forced sterilization. After the Nazis latched onto these ideas and did their best to put them into practice, eugenics (thankfully) fell out of favor.
We've also seen evolutionary ideas seep into economics, with emphasis on competition in the free market that weeds out weaker businesses.
The latest frontier is evolutionary psychology, which seeks to understand every human thought, behavior, and emotion in light of how it might have helped our ancestors survive. While most people find it depressing to think of things like love, art, faith, culture, and friendship simply as adaptations that enabled humans out-compete the Neanderthals, these psychologists often seem to derive pleasure from trying to deflate others' beliefs and values. (On the other hand, one could argue that evolutionary psychology itself is simply an adaptation to survive in the crowded environment of academics and compete for limited resources such as funding and tenure.)
Summary
The theory of evolution has become the dominant theory for understanding biological science.When Charles Darwin first popularized it, he was met with controversy, but the fact that the theory explains many phenomena under one umbrella has enabled it to persist.And yet, outside of the scientific world (and to a small degree, within the scientific community), the theory of evolution is still controversial, and many Christians see it as a denial of mankind's special place in creation and a contradiction of the Word of God.