Saturday, November 19, 2016

Misconceptions that non-creationists have about evolution

Creationists have all kinds of misconceptions (and distortions, and straw-men, and even outright lies) about the theory of evolution. But this post is not about them. It's about common misconceptions that non-creationists, even those who fully accept the theory, often have about evolution.

The "evolutionary ladder"

This is a very old myth about biology that goes back hundreds of years, well before Darwin. In fact, Darwin's books about evolution argued against this (instead proposing an evolutionary tree, where all species are on an equal level at the ends of the branches.)

The idea is that there are rather discrete "steps" to evolution, and different species are at different levels on this "evolutionary ladder". At the top are, of course, humans. Below them are apes and monkeys, and so on and so forth, neatly classified in terms of complexity and evolutionary progress.

This leads to the thought of "taking the next step" in evolution. We are at a given level in the ladder, and when we "evolve enough" we'll transfer to the next step above it.

While sometimes the expression "the next step in evolution" is used more figuratively, way too often it's used too literally, as if there indeed were discrete steps or jumps that can be distinctly measured or described. That's just not how evolution works in reality. It's a very gradual and much fuzzier process.

The "direction" of evolution

Even more prevalent is the notion that evolution has a direction. Everything is evolving towards being more complex, more "evolved", better in every way. Oftentimes this misconception goes so far as people thinking that given enough time, we'll evolve into energy beings or something. Underlying this thinking is the idea that evolution has a goal and a direction.

That's not how evolution works at all. Evolution has no direction, no goal. It's a completely mindless natural process that just happens due to physical interactions between entities and their components in the physical world. It has no intent, no purpose, no goals, no direction. It just happens. It's like a river that changes shape over time due to erosion and natural phenomena: It has no goal or intent in mind; it just happens due to how the physical elements interact with each other.

Evolution is just the variation that happens from one generation to the next (which is why it's often described as "descent with variation"). Some of those changes may help the species survive better than other changes. The part of the population that has lesser chances of survival due to a particular change may die off more easily, and thus the changes that increase the chances of survival get naturally selected into the species (and natural selection is, once again, just a mindless natural process that simply happens; it's essentially emergent behavior.)

Sometimes the changes may be considered (by a very subjective measure) to have made the species "more complex" or "better", but that's not necessarily always the case. Sometimes a change that makes the species "less complex", simpler, might help it survive a particular environment they find themselves in. Maybe they lose something they had, or something becomes more "primitive", and it just happens in that particular environment to help them survive better. (That's why some species have eg. lost limbs over long periods of time, for instance.)

Descent with modification, with natural selection, simply makes a species adapt to its changing environment. No intent, purpose or goal; it just happens due to blind physical interactions. If a sizeable group of that species moves to another location, or the environment changes for other reasons, it often causes for a different set of changes to be naturally selected (because the part of the species that happens to get such changes has a better survival rate, the rest dying off, essentially becoming "extinct" over a long period of time within the species itself.) If the species does not adapt, eg. because those necessary changes just don't happen, then it may die off completely (which happens quite a lot).

This is closely related to the next point:


This is the notion (especially loved by Hollywood) that a species, or even an individual, can "de-evolve" into a more primitive form, into a past ancestral form.

This is nonsense. There is no "de-evolution". There is only evolution. Evolution is that: Just change in a species over time. It doesn't matter what kind of change, or what "direction" that change may take the species (as there is no "direction" to evolution).

As noted earlier, sometimes the changes might make the species resemble a distant ancestor species. It may even be that some genes that had been deactivated some time along the line become once again activated, and thus something that was changed in the past becomes "unchanged". But this is not "de-evolution"; just evolution. Genes combine, they change, sometimes they mutate, it's all just change.

A closely related concept is that genes somehow have a "memory" of what they were in the past, and this can cause the species (or even an individual) to be able to revert to a previous form. Again, mostly nonsense. If something has changed, it retains no "memory" of anything.

Let's use an analogy using words (which is quite a popular analogy with these subjects). Assume I have the word "CAR". Now we make a random change to it and it becomes "CAT". Does this new word somehow "remember" that it was "CAR" in the past? No. If another random change is done to it, and it just happens to be the right kind of change, it might actually become once again "CAR". But that was just random chance, not because it somehow "remembered" that it was like that in the past.

(Caveat: Genetics is a hugely complex subject, and I'm a complete layman, so I may well be talking out of my ass here. As said, the subject may be made more complicated by the fact that sometimes genes can "turn off", while still being inherited to the next generations, and then perhaps "turned on" again by another random change. In this case the genes kind of "remember" their past because that particular one was never changed, just "turned off". In Hollywood science, however, the notion seems to be more esoteric than this.)

Individuals evolving

This is another favorite of Hollywood, but the fact is that individuals do not evolve! If you understand the theory of evolution at all, you would understand why.

The theory of evolution is a model that describes how a group of living beings (consisting of numerous individuals) that forms a species changes over time, from generation to generation, and how and why some of those changes remain while others disappear. These changes apply pretty much to the entire species (a certain small change may happen to a newborn individual, but over the next generations, if it's a successful change, it will "spread" to the entire species, as all the descendants of this individual pair with other individuals in the species, producing offspring that inherit that particular change.)

Individuals are different from their parents, and this is part of evolution (a very minuscule part, but still part of it). Individuals do not "evolve" during their lifetimes. They especially never experience radical changes like in some Hollywood movies; that's just a physical impossibility. Also, you can't make an individual "evolve", not even in theory, not be any conceivable means, because that's just not how evolution works.

The "intent" of evolution

Sometimes you see misinformed people talk about how this or that was never "intended" by evolution (or nature, or whatever), or that evolution (nature, whatever) "intended" us to do this or that. As a concrete example, I once had a discussion with a person online who thought that evolution never "intended" us to eat meat.

This is absolute nonsense. As mentioned several times, evolution is just a mindless natural process that happens automatically due to the physical interaction between elements and forces. It just happens. It has no mind, goal or intent. Evolution doesn't "intend" us to do or not do anything. It has no purpose, meaning, intent or goal. Saying otherwise is exactly as silly as saying that gravity "intends" us to do something, or electricity, or volcanoes, or the rain. They are just natural phenomena that simply happen; they have no intent, purpose or goal behind them. You wouldn't go around saying "gravity never intended us to fly in airplanes"; that would be just silly. Then why would you go around saying "evolution never intended us to do this"? It's exactly as silly.

It's impossible to "against" nature, or evolution. In this sense there is no such a thing as something "unnatural". Everything is natural, because it happens in the existing universe. Likewise the notion of doing something according to nature or evolution is likewise nonsensical.

Of course some people (including creationists) could interpret that as everything being "permissible". No. That's not what it means at all. We, as a social species, survive when we work together and protect each other. We don't survive if we start harming each other. Harming each other would be simply stupid. (Unfortunately too many people do it anyway. Fortunately we have formed deterrents to avoid it becoming too common.)

Survival of the fittest

This is a notion shared by many creationists, but it is also a notion sometimes believed by non-creationists, sometimes by deranged (or just misinformed) individuals. And it's the notion that the expression "survival of the fittest" means the same as "survival of the strongest", which in turn means that the weakest members of the species should be disposed of.

"Fitness" in this expression is not talking about strength per se. It's talking about being adapted for survival in a particular environment.

With many species, especially social species, including humans, taking care of the weakest members of society is actually what has helped us thrive and survive as a species. Our "fitness" as a species is that we survive and thrive as a large group that takes care of its members. We are not physically very strong compared to other animals (especially predators), but we have something that most of them lack: Intelligence and skill. We are a highly social species that can organize, live in a "hive" of sorts, and have strength in numbers and in organization, with different individuals having different roles.

The misaimed notion that some deranged individuals have that evolution means that the strongest should live and the weakest die, would actually be detrimental for the survival of the human species. It's not how we survived and became so successful.

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