Today I am going to talk about how we know that evolution is true. Is that challenging? Reportedly one Victorian aristocrat remarked, “Let us hope that what Mr. Darwin says is not true; but, if it is true, let us hope that it will not become generally known." Can we and will we be better people by ignoring our true roots? I argue no. We should celebrate our true humanity. Natural selection answers two ancient crucial questions “Who are we?” and “Where did we come from?” Evolution can be a powerful source of non-mythical myth, and literal metaphor. It’s our story, and knowing it may be critical to our ultimate growth.
As much as we can know anything, we know evolution is true! There is considerable evidence for evolution that comes from many fields of study. Modern evolutionary theory is not all knowing, complete, or perfect, and it contains controversies. However no alternatives to the modern evolutionary synthesis are supported by any credible evidence. Alternatives typically do not offer evidence to support their world view, only assertions combined with criticism of evolution.
Creationists have said they can’t see how anything as complex as an eye could evolve. It’s been explained and scientists have documented across many organisms a host of intermediate stages in eye development, from light sensitive spots on flatworms to the amazingly sensitive eyes of hawks. Our eyes reveal a distinct marker of our evolutionary history. The wiring for the eye passes right through the visual field. That’s something no semi-competent designer would ever do. But evolution moves by small change, and doesn’t look ahead, so it often results in sub-optimal design. Our evolutionary history has left us a blind spot that our brain software usually hides from us. Squid on the other hand have an eye with a much better design. We are able to predict that any mammal, lizard, frog, or other vertebrate that we will ever discover will have an eye with the subpar design and that any unknown member of the squid family will have the better squid type design. Find one exception and the whole understanding of evolution is called into question. Creationism and intelligent design don’t offer such predictions. Certainly a Creator could have shown man’s prominence by making him the only vertebrate with a well designed eye. Eye’s tell us a lot, but it’s not just eyes, its bones, nerves, muscles, DNA sequences, body segmentation, proteins, organs and more. If you know an animal’s ancestral lineage then you can predict all sorts of characteristics you will and will not find. The discovery of new or existing species playing outside the established rules would start a domino effect toppling our basic understandings.
So evolutionary theory does more than provide explanations. We’re wired to make up and accept explanations. There’s nothing special just because an explanation resonates within us. What’s impressive is making predictions of what can and can not happen while offering new insights that can prove to be significant in the future. The evolutionary synthesis does that. Creationism and Intelligent design fail those tests.
In a field with so much evidence and so much support, it’s not surprising that opponents can find things to pick at in order to rally their supporters and sow confusion along the sidelines. Scientists and others have repeatedly addressed all significant objections to the theory of evolution. But opponents repeat, recycle and retool a multitude of old claims that seem somehow to challenge evolution. They are often presented shotgun style with the “questioner” moving on to the next question without listening to any replies along the way. They contain a litany of dubious to false premises such as, No missing links have been found, rocks can’t think, there’s not enough fossils, there’s too many fossils, random change can’t introduce new information, some things are irreducibly complex, radioactive decay has problems, Darwin was a racist, no one’s seen a dog give birth to a cat, evolution is only a theory, tornados can’t assemble jumbo jets out of junkyard parts, random mutations can’t provide new information, and behold the banana it’s just too perfect.
If you take creationists at face value, not only do you have to abandon biology, but also what we know about archaeology, linguistics, anthropology, astronomy, geology, physics, ancient history and chemistry just for starters. The pseudo- controversies and ill informed questions promulgated by creationism and intelligent design do not belong in our public schools. They do not advance knowledge, understanding, or critical thinking. They probably don’t do much to advance religion either.
Some who challenge evolution are seemingly more reasonable But arguments that evolution can’t produce love, laughter, art, or all the wonderful feelings and emotions humans are capable of experiencing are very similar to arguments that evolution can’t produce an eye or a banana. The limitations are not in evolutionary theory, but rather in the knowledge, creativity, and imagination of the critics. Invoking the supernatural to bolster explanations, leeches amazement out of our remarkable story. When evolution is seen as “touched” by the divine it robs evolution of its most profound implications that relate us directly to all other life on this planet.
Mixing theology (even liberal theology) with evolution is a bad idea. It’s a mix as grating to some as Lawrence Welk versions of Rock Classics. Advocates might say, “Well we’ve used your tune and most of the lyrics.” “Well yes, that’s true but in the process you ripped out the heart and soul of what made it special.”
I mentioned the predictive power of evolutionary theory. I’d love to share more but her are a couple examples: Combining the theory of evolution and plate tectonics it was predicted that marsupial fossils would be found in Antarctica before they were. Neil Shubin recently predicted that the ancestor between fish and amphibians would be found in 375 million year old rocks in arctic Canada. There he discovered tiktalic, a close relative of our ancient ancestors. When it was discovered that humans had one less chromosome than our ape relatives, this unexpected finding led to some predictions. Chromosomes look somewhat like bar codes of differing lengths and patterns. As chromosomes change very slowly, it was predicted that 22 of our chromosomes would line up with those of our nearest relatives and that the one remaining chromosome of ours would look a lot like a fusion of the two remaining ape chromosomes. That is exactly what played out and the astonishing evidence is only a Google away.
Jerry Coyne, in his Book “Why
Evolution is True” observes that,
In 1922 President Woodrow Wilson was asked about the theory of evolution. He responded, "of course, like every other man of intelligence and education, I do believe in organic evolution. It surprises me that at this late date such questions should still be raised.” Since then the evidence supporting evolution has increased exponentially and yet….
If you’ve found things I’ve said to be surprising today, I encourage you to begin exploring. We’re living in the 21st century and we have the privilege to know what our forbears could not. Evolution is your story. Welcome the truth of who we are and where we came from.
Reverend _____ will raise some questions and throw out some challenges. By all means, question evolution but please do so in the spirit of inquiry. Don’t be closed minded like the creationists and use questions as a shield, a barrier, or a mantra to keep the door shut on this most wonderful idea. A dialogue will serve us all well.
In closing let me observe: Nature gives us proclivities for kindness, empathy, love, and trust. Certainly it provides us with inclinations towards selfishness and dark emotions as well. It makes sense to think that we can best control and shape our emotions and proclivities the more completely and directly we understand them. That’s not to say we won’t make missteps or misapply knowledge. But if it is our intention to become kinder and more compassionate people, we will be more successful the more truth we know of ourselves and the roots of our behavior. Thank you Charles Darwin for enabling us to shine a light on those roots.