The cultural nose hypothesis

As Richard Dawkins put it in 1976:

Most of what is unusual about man can be summed up in one word: `culture'.

The human nose is an unusual feature of humans. Most apes have flat noses. Does culture explain the human nose? If so, how?

Several hypotheses come to mind. One proposes that big noses come with pronounced brow ridges which act to defend the eyes against being punched in the face - something which humans are much better at than our cousins. Gene-meme coevolution comes in here since accurate punching is tied in with rock throwing skill - which is a culturally-transmitted hunting technique.

Another hypothesis is that the nose acts as an air lock. The nostrils point down, preventing water from entering the nose during common swimming techniques. Swimming is a culturally-transmitted trait. Humans are much more water-friendly than other apes. Water is potentially a strong source of selection, since water entering the lungs can be fatal. Elaine Morgan is probably the best known proponent of this idea. She covers it in her book The Scars of Evolution, for example.

Another hypothesis is sexual selection. Whenever some part of the body grows to an unusual size, sexual selection ought to be on the table as a possible explanation. The nose of the proboscis monkey illustrates this possibility.

Lastly, northerners tend to have bigger noses than equatorial folk - suggesting that the nose acts as a heat exchange and represents one of many adaptations to living in a cold climate - somethings humans can do largely due to cultural transmission.

I tend to favor the 'airlock' hypothesis. The heat-exchange hypothesis predicts that most Africans should have chimp-like flat noses - which they evidently do not. The idea of a defensive barrier would suggest that males would have bigger noses than women. Similarly, sexual selection typically affects traits differently in the different sexes. There is some nasal sexual dimorphism - but probably not enough for these theories.

I propose here that the 'airlock' hypothesis be promoted as the cultural nose hypothesis.

Medicine vs microbes: comparing evolutionary rates

Much has been written about how cultural evolution is faster than organic evolution. Unfortunately most of it is nonsense. The problem is that people compare the rate of evolution of humans with the rate of evolution of memes - which typically have a much shorter generation time. This comparison is unfair and unhelpful - as I've previously documented my previous article: On the rate of cultural evolution.

A fairer contest would be to compare cultural evolution with the evolution of organic microbes. A natural experiment is currently doing that on an enormous scale. Hospitals and medical organizations wage constant war on microbes. In some cases, humans care quite a bit about the outcome - it can't be claimed that they aren't trying. This contest gives us some data about the relative rates of evolution in the two realms.

Looking at this data, it's hard to make much of a case for cultural evolution being faster. The extinction rates of disease causing microbes are especially poor. Perhaps, one day, cultural evolution will clearly outstrip organic evolution - but we don't seem to be quite there yet.

Domesticated humans

Humans have domesticated many memes - making them less harmful and more docile and friendly servants via selective breeding. In modern times, this idea is often called domestication_theory.

However there's also an important sense in which humans themselves have been domesticated by the organizations they are part of - the companies, governments and churches they associate with. The image shows some domesticated employees of Toyota in Japan.

The signs that humans have recently been domesticated are widespread. Protection and food production have both been outsourced - as with domesticated animals. The modern shrinkage of the human brain can probably be attributed to domestication.

Domestication and neoteny seem to be associated. Young domesticatees are often more docile, and are more easily moulded by the domesticator. The longer the child-like stage lasts, the better. Domestication and imprinting are also related ideas: the domesticator often benefits if the domesticatee imprints on them.

The process has sometimes been described as "self-domestication". The term "self-domestication" suggests that humans domesticated each other - while it seems to me that the truth is more that organizations and institutions domesticated humans.

Slavery, wage slavery and imprisonment represent fairly clear cases of domestication in progress.

The organizations of today that have domesticated humans are products of genes and memes. However, without the memes they would not exist in their current form. So, in a sense, memes are domesticating humans. It seems likely that this will become more true in the future, as automation gradually replaces the human components in organizations with machines. Humans originally domesticated memes. Their domestication in turn by organizations represents a bit of a role-reversal.

References

• Brüne, Martin (2007). On human self-domestication, psychiatry, and eugenics
• Leach H.M. (2003) Human domestication reconsidered
• Guy, Allison (2011) We domesticated ourselves
• FRANCISCUS, ROBERT G. , MADDUX, SCOTT D. and SCHMIDT, KRYSTAL WIKSTROM (2013) Anatomically modern humans as a ‘self-domesticated’ species: insights from ancestral wolves and descendant dogs
• Wilson, Peter J. (1988) The Domestication of the Human Species

Memetic assimilation

One of the basic ideas of gene-meme coevolution is genetic assimilation. The concept refers to acquired phenotypic traits turning into genetic ones over time. In the context of cultural evolution it usually refers to learned behaviours becoming encoded in DNA genes.

Examples of genetic assimilation in action include walking, speaking and eating cooked food. These all started off as culturally-transmitted practices, but became successful - and went on to be encoded partly in DNA genes.

The best way to intepret the concept of memetic assimilation is probably to consider cases where traits coded in DNA genes get taken over by learned behaviours. To best carve nature at the joints, it seems best to ignore the distinction between individual and social learning in this case, and to lump them together.

Examples of memetic assimilation include:

• Human fur - largely replaced by bedding and clothing;
• Human large intestine - partly replaced by practices such as cooking and grinding foods;
• Locomotion - largely instinctive in many animals - humans learn to walk from their parents;
• Communication - largely instinctive in many animals - humans learn to speak from other humans.

Humans have large developmental plasticity. Many behaviours that used to be instinctual have been replaced by more flexible traits that are acquired through learning.

Since these are still civilization's early days, many of the more interesting examples of memetic assimilation seem likely to lie in the future:

• Memory - largely outsourced, reducing the human brain's memory to a local cache;
• Immune system - partly replaced by hospitals;
• Repair systems - partly replaced by hospitals;
• Digestion - partly replaced by food pre-processing;
• Thermoregulation - partly replaced by air conditioning;
• Transporation - scheduled to be largely replaced by cars and aircraft.

Since memes seem generally more flexible than DNA, it seems reasonable to expect that memetic assimilation will eventually go all the way - resulting in a memetic takeover. I.e. brains will be replaced by machine intelligence and bodies will be replaced by robotics and nanotechnology.

Terminology note: Memetic assimilation should be distinguished from meme assimilation - the latter being part of the process of meme acquisition - a normal part of enculturation.