BBC has an interesting article on the effects of culture on evolution.
You shouldn’t be able to drink milk. Your ancestors couldn’t. It is only in the last 9,000 years that human adults have gained that ability without becoming ill. Children could manage it, but it was only when we turned to dairy farming that adults acquired the ability to properly digest milk.
It turns out that cultures with a history of dairy farming and milk drinking have a much higher frequency of lactose tolerance – and its associated gene – than those who don’t.
Drinking milk is just one of example of the way that traditions and cultural practices can influence the path of our evolution. Culture and genetics are traditionally thought of as two separate processes, but researchers are increasingly realising that they are intimately connected, each influencing the natural progression of the other. Scientists call it “gene-culture co-evolution.” Why does it matter? If we can pin down how culture influences our genetic makeup – and how the same processes apply to other creatures too – then we can be better understand how the way we act as a society today could influence our future.
This makes a lot of sense if you think about it. Culture is part of the environment in which natural selection works.
I’ve recently come to appreciate the fact that natural selection doesn’t necessarily mean those without the adaptive attribute died prematurely. It could simply mean they were slightly less successful reproductively. An imbalance which, over thousands of years, can lead to the adaptive trait dominating in a population.
This also reminds me of the research which seems to be showing that the development of our large brains is probably largely due to our social nature. Being slightly more intelligent probably increased your ability to navigate social dynamics, giving you a slight reproductive edge. Over hundreds of thousands of years, this is probably what led to a rapid increase (in terms of evolution time frames) in our species intelligence.