I want to start this post by saying I’m sorry. I’m sorry to have been absent for a while now,Forgive me but here is the reason.
Have you ever wondered how humanity came to exist as it is today ? I’m pretty sure you have . Evolution is complex. One way to explain it simply is just ‘trying to get better’. You evolve to live better, longer and happier.
Paper Title: How culture shaped the human genome : Bringing Genetics and the Human Sciences together
What it really means: We live in a constant cycle of change between who we are (genetically/culturally) and where/how we live.
It has been suggested that evolution of humans occurs mainly due to the need to live and look for drier and cooler habitats. It’s also been suggested that due to heat humans evolved hairless skin and sweating. This sounds actually quite plausible and for the most part, is actually true. This proves that the environment (geographic, temperature etc.) forces genes to evolve.
Think about it. Over the past 50,000 years humans moved from Africa to all over the world, endured an ice age ( environmental stress), discovered fire (different cooking/food), exploited agriculture (more constant and varieties of food), observed increased population density (more need for strategic consumption), domesticated many species of animals and plants (new proximity to animal pathogens, new immunity ). This is all true, and all of these environmental changes (except for the ice age) were caused by us.
What I’m getting at here is that not only does the environment make us who we are, we IN A WAY forced ourselves to become who we are.
To give you a simple and highly interesting example, human beings were mostly intolerant to lactose before the advent of farming. However once human beings established farming, a lactose tolerance allele proliferated rapidly, allowing us to digest cow milk! Another example would be the evolution of jaw muscle fibers (ours are weaker than our ancestors’) when cooking was invented.
This process is called gene-culture evolution, and experts suggest that this kind of evolution is way more faster than any other.
To leave you on a special note, imagine the society of today, which is quickly changing through the new technological advances such as smart phones or watches. Will this huge cultural change affect our genes in the next 10,000 years ? Probably, but how ?
One idea that has started to emerge, is that humans are slowly becoming less fit to memorize information but at the same time more fit and fast in finding it (On Wikipedia or anywhere on the internet).
What are your thoughts ?
- Laland KN1, Odling-Smee J, Myles S. How culture shaped the human genome: bringing genetics and the human sciences together. Nat Rev Genet. 2010 Feb;11(2):137-48. PMID:20084086.