Generalizing Natural Selection
(Note: What follows are my personal thoughts on Darwinism and its extensions. You may find more authoritative information on this subject by looking for materials related to Universal or Generalized Darwinism. Admittedly, I have not read too deeply into the subject.)
You are surely familiar with natural selection, the process by which organisms with different traits experience different rates of survival and reproduction, as a result of their respective traits. Originally proposed by Charles Darwin, it serves as a key mechanism for the process of evolution, which gave rise to the vast array of different organisms we see today.
My first exposure to the idea that natural selection is a specific realization of a more general principle, instead of an exclusively biological process, came from reading The Selfish Gene about 10 years ago. In the book, Dawkins coined the idea of memes, which, roughly, are gene-like units of human culture which, according to their specific properties, have differential rates of survival and reproduction. Memes (in their original sense, not in the sense they carry today, of Internet memes) are a powerful concept, so let’s delve into them a bit further.
Properties of Cultural Memes
A meme, as I interpret it, is just an individual unit of human culture. Memes can be concrete, like tunes, or abstract, like patriotism. Although memes often function as individual units, they can be composed of numerous constituent parts, just like genes; for example, the notes of a tune unite to become a distinct sequence with properties beyond the constituent notes, similar to the function of nucleotides in a gene. As with genes, memes are not always precisely defined; it can be a matter of definition whether a particular song is a meme, or instead a collection of tunes, themselves each memes, which are often linked together. We don’t need to be so precise here; the general properties of memes (or strongly associated groups of memes) matter much more.
Continuing the comparison with genes, memes can change; a gene’s “code” can change through the substitution, addition, or deletion of nucleotides, while a meme’s “code” can change through the alteration, addition, or deletion of its components. While memes are not replicated directly through the formation of biological offspring, memes are propagated throughout a population through communication, whether verbal or nonverbal. For example, a simple myth, which can be considered a meme, can be propagated through a community, or even a civilization, if it is communicated within the population enough.
There are many ideas and cultural phenomena we could consider to be memes; we already mentioned tunes and myths, but more general ideas, like the belief in a form of eternal punishment, can also be considered memes. Even Internet memes, the most common usage of the word meme these days, are memes, in the cultural sense. While harder to precisely define as with genes, we can think of memes as individual components of human culture.
Cultural Selection
With natural selection, genes which benefit the survival and reproduction of an organism will tend to become more prevalent in a population. This is not due to any form of intent on behalf of the gene, but is just a natural consequence of specific entities having an advantage over others.
Just like natural selection governs the process of biological evolution, cultural selection governs the process of human cultural evolution. Specific ideas, or memes, given that they have characteristics that are advantageous for surviving and propagating within a population, will tend to become more prevalent within a population over time. This can occur without any conscious effort on behalf of the people involved. Reproduction, in the cultural sense, is achieved through transmission; ideas which people want to spread naturally become more prevalent than those that don’t. Survival of a cultural meme entails some degree of durability, or even permanence. The more impactful or memorable an idea is, the longer it will survive within the mind of its holder – all the better if it is an idea which lends itself to widespread transmission.
Cultural memes, just like genes, can die out, through the cessation of the cycle of survival and reproduction. When an organism dies, the physical manifestation of its particular genes die out, although if the organism has reproduced, copies of its genes will live on in other organisms. The same applies to cultural memes; when a person carrying a meme dies, or when the meme dies (i.e. is forgotten) inside a person’s mind, the concrete manifestation of that meme, concerning that person, ceases to exist. Of course, if the person has transmitted that meme to others, then the meme will live on in their minds. Furthermore, as ideas are often transmitted imperfectly, the surviving (or “offspring”) memes will often have some variation, leading to a diversity in characteristics. Just as in natural selection, those variants which lend themselves the most to transmission and propagation can be expected to become the most prevalent in the population.
A song, for instance, can be “catchy”, an excellent trait to have for survival, in the sense of lasting longer in peoples’ minds. If people are embarrassed by the song, they will tend to hesitate to propagate it, and we should generally expect it to not propagate too far in the population. On the other hand, if it is a universal hit, we can expect it to reach a significant chunk of the population. In such a situation, the song will experience high rates of reproduction (through transmission) and survival (through catchiness), making it far more commonly encountered than songs lacking either of those traits.
I must stress that the similarities between genes and memes are not infinite. Genes, unlike memes, can last millions of years (well, in theory, I suppose memes could too.) Memes, unlike genes, can be rediscovered through written materials even after ceasing to exist within any human mind; a good example are old stories told in recently discovered historical artifacts. Genes are bound to rules of biology that memes are not; memes are bound to rules of human thought that genes are not. The reason why genes and memes share so many similarities is because they share fundamental properties with each other, and exist in specific environments that share other fundamental properties. Naturally, where these properties differ, genes and memes diverge in behavior and characteristics.
Generalized Selection
The theory of natural selection seeks to explain the origin of species. Over long periods of time, the species alive today came to be largely as a result of incremental adaptations suitable to the surrounding environments. Organisms with these adaptations gained advantages in surviving and reproducing, eventually making their genetic composition more and more prevalent among the relevant populations.
What’s important to note is that these adaptations are not necessarily planned, nor intentional. The process of natural selection unfolds in an almost mathematical way, where slight variations in genetic composition lead to different rates of survival and reproduction within a population. That alone, without any sort of conscious effort on behalf of the involved organisms (and genes), is enough to drive the process of evolution. The same is true of cultural selection, where, even without humans trying to spread cultural memes for the purpose of disseminating them to a large group of people, memes with different properties will experience different rates of survival and reproduction within human populations, resulting in a gradual evolution of memes within a population.
What underlies both natural and cultural selection is the presence of a few key phenomena that allow a specific instance of a generalized selection process to occur. Although not completely precise, a selection process should generally occur within a system given the following conditions:
- A population of individuals which, under certain conditions, will die
- An environment containing these individuals, which can bring about the conditions necessary for their death
- A reproductive mechanism for individuals to propagate their characteristics, upon surviving long enough
- Variations among individuals, which influence their ability to survive and reproduce within the environment
Given these properties, individuals within the system will exhibit different characteristics due to the inherent variability within the population. Within the environment, individuals must compete to survive, and those with the characteristics most suited to survival will tend to survive more frequently. Given this increased rate of survival, the individuals with advantageous characteristics will also tend to reproduce more, which ensures their traits are present in a greater percentage of the population in the future. The cycle continues, and this differential rate of survival and reproduction – selection pressure – will gradually result in evolution.
We can now see how both natural selection and cultural selection fit into this model. For natural selection, the literal environment, whether it be a savannah or the deep sea, is the environment with limited resources (food, water, land, etc.) Any population of organisms, assuming there are enough to make the necessary resources limited, will have to undergo competition for the limited resources within the environment necessary for survival. Those individuals best suited to their environment – for example, with better vision for spotting food, or more strength for fighting foes – will tend to have more offspring, resulting in a change in gene frequencies in the next generations of organisms.
Cultural selection is similar. In the space of memes and ideas, the environment is the human brain, which is fundamentally limited in nature, in both capacity and attention. Memes occupy our minds, and the memes which lend themselves most strongly towards being remembered will tend to survive the longest. Each meme is different – think of songs, customs, and inventions, for example – and the various properties of each meme – catchiness, usefulness, perceived importance, etc. – will largely determine how long each survives within a person’s mind. The reproductive mechanism is communication, whether through oral, written, or other means, and those ideas which lend themselves well to being communicated will spread throughout the population more thoroughly. Over time, some memes will die, while others will passed down for generations.
One important point to make is that genes and memes exist on two entirely separate planes of existence: biology, and human abstraction, respectively. While these two domains are connected – a human being that feels the incentive to reproduce will likely tend to reproduce more than one who does not – they are still separate, and we should not conflate the two, or frame one in terms of the other. Genes will tend to become more common within a population if they aid their own survival and reproduction more than others do, and memes which aid their own survival and reproduction will tend to become more prevalent within a population, regardless of whether they aid biological survival and reproduction.
Read Dominant Cultural Ideas next