What Evolution Is Not
In Parts 1-4 (here, here, here, and here) I’ve summarized how science sees the world and does its business. Now I invite you to stand at the kitchen sink and look out the window with wonder. Let’s see what the world has to tell us. But first, before we do that, let me take a moment to outline a few things that evolution is not. The word is banged around so much in so many contexts that it can be hard to remember exactly what it is:
Descent with modifications brought about by natural selection resulting in a change in allele frequency in a population.
That’s it. It’s a mouthful, but don’t make it too difficult.
1. Evolution is not abiogenesis
Abiogenesis is the study of how life began from non-life. By definition, this isn’t a component of evolution which is properly the question of how life diversified. Life, of course, had to be functioning on earth in some manner for it to diversify. This is an admittedly difficult subject and a snag that you will be drawn into if you engage at all with creationists.
Creationist literature will chide the evolutionists for believing in ‘spontaneous generation,’ an idea finally put to bed by Pasteur. That they conflate abiogenesis with spontaneous generation is telling. Note that the ‘beginning of life’ was anything other than spontaneous. Molecular evolution has recently been snagged by some in the Intelligent Design creationist fold as a fine example of creation: surely it takes a mind to invent life from non-life. This might very well be true, and there is a branch of creationism that argues as such, called ‘theistic evolution.’ These folks believe that G got the evolutionary ball rolling, and then stepped back to let nature take its course. This describes most of the religious. Unfortunately, propositions about god cannot be shown with hold-in-your-hand evidence. It might be true and it might not be true: we have no way of knowing.
This is far and away the most mis-queued topic in evolution. Evolution explains the diversity of life, based on descent with modification and selection. It does not explain, nor seek to explain, the origin of life. Biologists don’t even have a standard definition of life. It’s a fascinating and difficult topic, and I’m frankly unsure that we will ever come to a hard consensus on it. Abiogenesis differs from evolution in that there is just so little evidence left behind. Forget fossil bones – how about looking for ‘fossil molecules’? But we have glimpses based on climatology and geology and chemistry from which we can make predictive models. Maybe these will sort out one day to paint a more clear picture for us?
When banged over the head by someone demanding that you prove how life started, there are a couple of things to consider. The first is to avoid what I call the ‘0-100 miles per hour’ question. You will invariably be asked how you can believe that a couple of unrelated molecules roiled in a pond until a man walked out. It’s silly and ignores a few billion years, but expect it. What we know is that it is possible that certain molecules could combine with others to transform in such a way as to have new reproductive and self-organizing properties. Once this domino-type chain begins, could it be possible to continue replication until organics appear? Evidence says yes.
Forget the question of how randomness drives this. There is little in nature that is entirely random. Everything in nature – including molecules – act according to the physical laws of their materials. They must or the universe falls apart. Molecules and proteins fold, attract, and repel according to natural law. There is nothing different about ancient or modern molecules. And when you are asked to explain what existed before the Big Bang – the question will be more of a demand – just be honest. Shrug your shoulders and say that you haven’t a clue. It puts you head and shoulders above anyone else who thinks they do.
2. Evolution is not a formula
Another misconception about evolution is that it is a simple formula and, like the quadratic equation, if any term is wrong then the whole thing fails. This is partly tied to a misunderstanding of what a theory is (see Part 2). Equating evolution to an equation sidesteps the definition that a theory is an overarching description of processes we see repeated in nature. This error rolls in like a flood when research shows that scientists have been wrong about something or if anything in biology needs tweaking. “See! Dawkins said this and now we know that he is wrong! So evolution can’t be true!” The real truth is that when research or observation shows that our predictions or hypotheses are wrong then we edge closer to a better description of nature. Knowing what a thing is not is just as important as knowing what a thing is.
Does this make evolution tautologous? No. No more than chemistry or quantum mechanics or acoustics is. Is evolution falsifiable? Yes. Fossils could be found out of place. Dating discoveries could upend our time-line of geology and biological development. Genetic relationships could show that we are wrong about the concept of species and relatedness. For now, though, all that we learn builds a better case for Darwin’s dictum of descent with modification and natural selection.
3. Evolution isn’t about individuals
You do not evolve. Populations evolve. Individuals evolve only in the way that Brad Pitt has evolved to be a better actor since Fight Club as if that’s possible. Individuals are selected for by their environment, and those who are most fit to reproduce create more offspring. With each generation, natural selection alters the genotype of the population.
So far, genetics doesn’t appear to change this model. Epigenetics is the term used for non-sexual genomic changes that begin from outside or external factors. So, while it appears that epi events participate in evolution, the genome isn’t changed in the offspring. The same complement of genes and epigenetic factors can be passed to offspring that may or may not exhibit the same characteristics of the parents. For now, the jury is out. Epigenetics is an exciting and profitable study, but the contribution to evolution is still not understood.
4. Evolution does not explain everything
Not every characteristic of every organism has a direct evolutionary correlation to reproductive fitness. Where to draw the line is one of the constantly moving questions in biology. Quora – that bastion of silliness – is full of questions similar to “How does a man’s nostril hair relate to evolution.” Yes. I’m making this question up, but barely.
Go here to read Stephen Jay Gould’s and Richard Lewontin’s famous paper The Spandrels of San Marcos that explores this question.
5. Evolution is not anti-religious
Science doesn’t care one whit about religion, but only about repeatable, measurable, predictable, and tangible evidence. Because religions tend to argue from outside the realm of the material world, the scientific method doesn’t usually apply to religious claims.
That being said, it will not go unnoticed by the most casual observer that there is a small, loud, and primarily American subset of thirteen people from a particular division of a specific religion that rejects evolution because it evidentially argues that human beings are not a special creation of recent origin but instead share a common lineage with all organisms spanning the last billion years of life on earth. Bully for them. Evolutionary theory requires no belief in anything other than the reality and repeatability of nature.
Neither will it go unnoticed by the most casual observer that there is a loud and mean-spirited cadre of working scientists who think all religion to be daft and untenable, Bully for them, too. They’re just as wrong as the religionist who argues for young-earth creationism. C’est la vie.
If you missed it above, see these four posts to catch up:
Be sure to sign up for posts notification. I’m working on a new book with the working title of A Field Guide To Evolution. Probably out in a year? It’s big.
Also, if you sign up, you get a newsletter and can put your name in the hat for occasional freebies…
Thanks so much for reading. Can you think of someone else who would enjoy the post? Please mail it to them or share with your favorite social media using one of the icons below. And won’t you follow me? You can do so in the sidebar. Thanks again! And feel free to comment!Thanks so much for reading. Won’t you submit your email address in the pop-up? Then you’ll know when I publish another post. Thanks again! And feel free to comment!