Right.
There are two disclaimers here that are important: One, I am heavily biased here. Two, it is very difficult to make a statement that holds true 100% of the time in the biological sciences. This second one is important, as it shows how amazing Darwin’s idea of descent with modification was- this is possibly the only thing in biology that is universally true.
This is basically a response to the idea, that I hear espoused a lot, and formalized in Idiocracy, that we are losing some kind of race by keeping “less fit” people alive.
I will agree that there IS some conflict between classical evolution and human society; but the thing here is that “classical” evolutionary theory is wrong.
Wrong may not be the word, the more correct definition is “outdated”
There is a movement (of which I am a part of) that is trying to get past the strict “gene-for” rhetoric that has dominated evolutionary thought since the modern synthesis. Most of us are adamant about the fact that genes are only one factor out of approximately three other important factors in determining “fitness”.
Before I get to that, one more aside. “Fitness” is an extremely misunderstood idea. Again, not to pick on the person who said this to me specifically…
The individuals with the genes that allow greater ability to propagate their genes (whether it’s through surviving, energy conversion, sexual attractiveness, etc etc) in modern human society do not pass on those genes to offspring in a meaningfully larger number than those who have weaker propagation genes.
Even without asking “citation” on this, it is very easy to dismantle this idea. IN short, if a gene has passed on to the next generation, its fitness is 100%. There is no such thing as a “weaker” or “better” gene if ultimately that gene has been successful at replicating into the next generation.
The extension of this erroneous idea is that we, as a society, keep “unfit” individuals alive, or at least help them reproduce in ways they wouldn’t be able to in some mystical time when we apparently didn’t do this. This is again a misunderstanding of evolutionary biology by the layman, and unfortunately it is a VERY dangerous misunderstanding. When this argument is made, there tends to be a dichotomy between “society” (or “technology”, or “culture” or something else. Insert what is appropriate) and “evolution”. That is, people argue that society is “fighting against” evolution in some way. This is sort of true, if we ignore a lot of other aspects of evolution, but it ultimately falls flat when you realize that evolutionary biology focuses not on individuals, but on populations. In that sense, and if we take our species as one “population” , we are STARTLINGLY fit, as a population. It is important to note here that I define population as “a group of organisms living together at the same time who exchange genetic information”. To say it another way, society (culture/technology/whatever) is focused on keeping the human population reproducing, and in that sense it is not fighting evolution at all. To tie this back into my initial point that there are people like myself who reject genetic reduction in biological evolution, consider the means through which society increases the level of fitness for the human species as a whole.
Most often, it is through non-genetic means, generally adaptations that increase fitness after the genes have done their thing and built an organism (and sometimes during this process!). This is a concept known as “phenotypic plasticity”, and my bias here is that this is my area of focus. This is the second of the three things I mentioned that were important to evolution. Right now we have “genes” and “phenotypic plasticity”. Most of you know what genes are, and here is a formal definition of phenotypic plasticity: The ability of an organism to alter its phenotype in response to its environment.
To fill out my three things, “luck” is my third thing, and it sort of affects everything (we all play RPGs, you should have seen that coming).
Think about this for a second. Almost every aspect of society falls into this definition. Medicine. Cars. War. Benevolence. All of these things are not directly coded for in our genes, yet all of them can increase (or decrease) our population’s fitness.
Now you might ask “But RZINZ, I know a bit about evolutionary biology, and doesn’t this sound like Lamarck’s inheritance of acquired traits?”
Good question! The answer is that phenotypic plasticity is heritable not through the changes effected by the environment, but rather the heritable bit is how responsive your overall genotype is to the environment. That is, over time, evolution by natural selection* will focus in on those who are most adept at responding to their environment. In a simpler example, consider a predator. Which predators, given equal genetic information, will be most successful? Those that through a combination of luck and ability to respond to the situations they are placed in, are able to survive and reproduce more often.
In our case, our society has been “selecting” for the ability to alter phenotype since before we invented agriculture (I would argue). This means that on the whole, we are selecting for people who can reproduce no matter their circumstance.
To sum up, fitness (and evolution by extension) is not just about what your genes say. It is also about being in the right place at the right time, as well as receiving the correct stimuli to display the most adaptive phenotype, and finally
Fitness does not mean “healthy”, “strong”, “smart”. It simply means “good at reproducing”.
To add something else, I would personally like to see us emphasizing “survival” in the idea that fitness is a measure of how good you are at surviving to reproduce.
As a final aside, it is also important to remember that “natural selection” is actually only one of many “forces” that act on evolution, and it is also important to keep the actual definition of evolution in mind. That is, evolution is simply “change in the gene frequency of a population over time”. Not increase, not decrease, not “change in best genes over time”, but simply “change in gene frequency”.
There, introduction to culture and evolution, by RZINZ.
