How Evolution Really Works

And why it matters that we actually understand it

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Image credit: Sciencing

There’s a lot of confusion about evolution, especially in the USA. Hardly anyone understands how evolution works and this leads to a lot of misconceptions, many of which are harmful in our everyday lives.

Too often in the USA, evolution is presented as “just a theory” as if the word theory meant “someone’s idea, an assertion, nothing of substance.”

In reality a theory is a coherent logical construct that serves to explain one or more observed phenomenon.

Einstein’s General Theory of Relativity wasn’t just an idea he had in the bathtub one morning; it was a coherent mathematical construct that showed how gravity works and it made several novel predictions about phenomena that could be tested. When these phenomena were tested, beginning with Eddington’s 1919 proof that massive objects really do “bend” spacetime, Einstein’s theory was shown to be indeed a very good description of how gravity works. It has since been confirmed thousands of times in dozens of different ways. GPS navigation systems, for example, depend on its mathematics in order to work properly.

So a theory isn’t simply someone’s bathtub idea, a personal assertion. It’s an intellectual framework that explains why some phenomenon or set of phenomena behave as we observe them to do.

When US schools pretend that evolution is “just a theory,” the intent is to portray it as something that can’t be proven and therefore something that can be safely ignored, especially when the preferred alternative is an infantile narrative drawn from the primitive tribal myths of a group of goat-herders who lived more than 3,000 years ago and whose ignorance was nearly absolute with regard to nearly everything.

Evolution is a fact. That’s why the antibiotics of the 1950s don’t work anymore: massive over-prescription by naïve physicians and failure to complete the full course of treatment by patients led very quickly to the evolution of bacteria that are immune to the early antibiotics. That same evolution is occurring still, which is why we have so-called “superbugs” that are untreatable by any antibiotic in the pharmacological arsenal.

Researchers routinely use drosophila melanogaster to explore evolutionary mechanisms, as these little creatures can produce a new generation every three weeks and thus evolve quickly enough for a five-year research project to show significant evolutionary effects.

In short, we can see evolution happening right now in many different ways.

Unfortunately, even among people who are intelligent enough to realize that evolution is an excellent descriptor of things we can observe every day, it’s still too often misrepresented. The classic misrepresentation is the notion of “survival of the fittest.”

When Darwin used the word fit, he did so in the context of his time. For Darwin, as for other Victorians, the word meant “suitable for purpose.” It’s latter-day meaning of “strong” was barely known in Victorian times. It would have been better for posterity if Darwin had used a phrase like “survival of the best adapted” but how could he have known that such a simple and obvious word as fit would change its meaning significantly in a future he would not live to see? Who of us can predict how today’s everyday words will change over the next hundred years?

Evolution is most certainly not about “only the strong survive.” Evolution is not a trashy Hollywood movie about lone cowboys living a macho pseudo-independent existence on the prairie. Evolution is about whatever serves to increase an organism’s chances of survival and propagation. And because there is a wide range of ecosystems and a wide range of potentially adaptive strategies, we see a wide range of phenotypes and behaviors.

The only rule evolution knows is “what works, works.”

Evolution has no purpose in mind. It’s not teleological. Evolution is the accretion of random mutations over time, a tiny percentage of which will be helpful and therefore possibly conserved while the neutral and deleterious mutations will tend not to persist. There’s no sense of moving forward to higher and higher creatures with humankind at the pinnacle. It’s all about adapting to the environment on a moment-by-moment basis.

The narrative of “only the strong survive” leads people into intellectual mistakes such as believing that human society is all about ruthless competition; the winners get rich while the losers get screwed. Although this is true in the USA, it’s not a consequence of evolution but rather a consequence of a system of governance whereby the rich purchase political favors at the expense of ordinary people. This isn’t evolution: it’s corruption pure and simple.

Equally, many on the left imagine that evolution and capitalism and “the patriarchy” are all interconnected in some unexplained manner, so it’s essential to denigrate evolution because they don’t like the US version of pretend-capitalism. But that’s like saying we should ignore gravity because we don’t like being fat.

Some like to co-opt evolution to support whatever pet theories they have, which are invariably political. For decades the US right-wing has pretended evolution is all about dominance and exploitation as a way to indoctrinate people into believing that US exploitation is somehow the “natural” order of things. Meanwhile on the lefty-trendy side, others claim that “really” evolution is all about co-operation.

In reality, evolution is about whatever works for a particular circumstance. Evolution isn’t interested in puerile political nonsense.

With regards to cooperation the picture is very broad indeed. Some unicellular organisms show no cooperation at all while others, for example certain types of bacteria, form mats that help them thrive as a group. Moving to multicellular organisms we see once again that some are entirely individualistic (crocodiles, most species of spider, prey mantis, most large felines) while at the other end of the spectrum some are highly cooperative (ants, termites, bees, female lions in a pride, some species of primate).

For our own species homo sapiens we see a mix of cooperation and competition. As we have no significant physiological traits to aid our survival in the wild, we depend on being part of a group in order to thrive. For most of our evolutionary history the group was genetically related and so altruistic behaviors would benefit the gene pool even at the occasional cost of an individual member of the group. But as group members aren’t clones (as is the case with ants, termites, and bees) we see less cooperation within a primate group than within social insect groups.

We cooperate for mutual survival, and we compete within the group for access to resources and mating opportunities. Each individual is likely to pursue a slightly different strategy based on circumstances. It’s no good pursuing a “might makes right” approach if the individual is small and weak; likewise it’s no good pursuing a “let’s band together against Mary” strategy if the individual is unable for whatever reason to form strong social bonds. As individuals we gravitate toward what seems to work for us, and different things work for different folks.

Evolution therefore explains why in the real world we see a wide variety of human behaviors in a wide variety of circumstances. Evolution doesn’t “make” us behave in a single way and certainly doesn’t enforce anyone’s political preferences or presently fashionable beliefs. Evolution cannot be summoned to the bench to support either fascism or socialism, capitalism or command economy, so-called “male” traits or so-called “female” traits.

Evolution also does not support any form of the 18th century notion of “a great chain of being.” Humans are not at the apex of evolution, any more than are bacteria or the Nautilus. We are just another species showing a particular set of adaptations. Evolution didn’t “intend” for us to exist any more than we “intend” the Andromeda galaxy to exist.

This is why people who say they believe in some child’s idea of an invisible magical creature that made the universe and has planned every single detail, and also say they believe in evolution, don’t understand evolution in the slightest.

While religionists who proclaim their belief in “intelligent design” are very stupid indeed, the one thing they are correct about is that evolution and religionism are mutually antagonistic. You can believe in fairytales about gods and goblins or you can understand reality, but you can’t combine the two.

Evolution is not teleological and it is not simplistic.

When we stop trying to bend evolution to support whatever transiently fashionable beliefs we may hold, we can start to look at what evolutionary theory can tell us.

One of the things evolution can tell us about our own species is the simple fact that our brains are highly adapted to do as little thinking as possible. This is because during the vast majority of our evolutionary history thinking was often a significant liability. An active brain can consume 30% of the blood’s glucose, and that energy could be needed to power muscles to escape from a predator, forage for food, or build a shelter. So we’re evolved to accept assertion from authority figures rather than attempt to reason things out for ourselves.

We’re also evolved to be part of a group, and be suspicious of other groups.

It’s not difficult to see why a lot of people are so easily led by the nose by blustering demagogues who stir people up against foreigners, immigrants, people of different political or religious beliefs, etc. We’re basically hardwired to be dupes, easy marks for those who cynically exploit our mental biases. Until and unless we understand our habitual limitations we’re unlikely to look for ways to mitigate them.

Understanding evolution has profound implications, few of which we’re even beginning to grasp.

We can start by clearing our heads and trying to get a clear view of what evolution really is, and that in turn starts by understanding what evolution is not.

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