Human beings are phenomenal creatures. Out of the millions of species that are estimated to exist on earth, we are one of the most successful. What precisely marks us out as humans though, as separate to the other great apes, is still under discussion. The set of cognitive characteristics that have traditionally been used to distinguish us as human are rapidly narrowing – we not are the only ape to use tools or believe in fairness, both things we once thought were uniquely human. One thing that is unique about us though is that we are the most flexible in terms of our habitat. If the place we find ourselves living in doesn’t suit us, we either change the habitat, or change our technology. It’s a pretty neat survival skill when you think of it.
Human beings have been anatomically the same for around 200,000 years, living only in Africa for much of that time. If a human being born 100,000 years ago was magically brought up in the 21st century, you would never know the difference. However, around 40,000 years ago some of us started moving out Africa – to places that were very different. We survived because we could control fire, eat a variety of food-stuffs that came our way and create clothes and tools appropriate to our new surroundings. Our lives consisted of heavy exertion to get food, then rest days after. Our food consisted of fruit, vegetables, nuts, roots, meat and fish. Now we weren’t the only hominin (human or human ancestor) around at this time. No doubt you know the Neanderthals, and may have heard of Homo Florensiensis, which was probably around until about 12,000 years ago. Why did we make it, but our other bipedal relations not?
The answer is pretty much because we are flexible. Using technology and foresight, we can hunt and gather at anytime of the day necessary. We are also omnivores, and so can live on both plant and meat based foods. If it’s too cold, we’ll just make a fire and put some clothes on. If it’s poisonous when raw, we’ll cook it, or domesticate it (i.e. selectively plant) so it’s not. Almonds are a good example of something that is poisonous in the wild that we cultivated into being non-poisonous.
That process of domestication really caught on around 10,000 years ago. We went from hunting and gathering food as we found it, to planting and planning our food production. This shift to farming happened around 190,000 years after we started existing, so we have only been farming for 5% of our existence. It’s no surprise then really that we are genetically still adapted to being hunter-gatherers.
Now you might be wondering why I have brought you on this evolutionary tale when you are here to read about public health? The most important point to take from all this, is that we are not living in the environment we are physically adapted to; it is vastly different, and that environment we adapted to no longer exists – it’s been replaced by farmland, cities, towns and road networks.
So, where does that leave us? I am not suggesting we return to a hunter-gather lifestyle – even I am not that unrealistic. Even if I were, farming has brought us some pretty good benefits. It’s allowed us to settle in one place and develop cities; specialise our workforce; improve human living standards and develop further technology. The reason I can provide you with this blog post today is that 10,000 years ago, some people decided to plant a row of seeds and stick around to see what happened. Farming wasn’t all good though: we started living with animals, which gave us new diseases; the quality of our diet actually decreased, and average heights reduced from around 5,10″ to 5,6″ in men. Only in the 20th century did we regain our height levels (except me for some reason). However, for all its pros and cons, agriculture is here to stay, and I think it’s probably for the better now there are 7 billion of us.
But do you remember why we out-lived all those other hominins? Flexibility. When our environment didn’t suit us, we changed it or invented a technology to deal with it. If there were trees in the way, we cut them down. No water? Build an aqueduct. My point is that if we find ourselves dying earlier than we need to because we just cannot resist the temptations that surround us (video games, fast food outlets etc), we can do something about it. Inventing technology has often been our way out of sticky situations, and it has been incredibly successful – we would not be here today without it; but let’s not forget that we are also succesful because along the way we have changed the environment we live in when we found it inhospitable or not convenient for our needs.
How do I know this for sure? I know this because we created this environment in the first place. We became farmers, built our cities, developed our economic and political systems. We hunter-gatherers moved ourselves out of the jungle and into urbanisation. When we needed water, we built reservoirs and canals; when we needed sanitation, we built drainage systems; when we wanted food in lots of different places, we designed distribution systems. The beauty of today’s world is that instead of adapting ourselves to the environment, we can adapt the environment to suit us. Nature still ultimately determines our food and resource availability, but as for the distribution steps after that, we are in total control; if we made that environment, we can change it.
A lot of effort is put into understanding our genes and physiology to develop better treatments, or even grow new body parts. I’m no geneticist, but doesn’t it sound easier and quicker to change something you designed (even if it still a complex system), rather than change something you don’t fully understand yet? As for pharmacology, it has already provided us with so many life-saving drugs, but for every drug a human being takes, someone has paid for them. Giving drugs to a large section of humanity for a very long time sounds expensive to me. I’m aware changing agricultural policies and urban planning is also expensive, but these are one-off costs that will last and benefit future generations.
Don’t get me wrong, the fields of genetics and pharmacology are vital for preserving and extending human health; but we should not rely on them totally when we already have an understanding of how we can change our physical, social and political environments to improve our wellbeing.
After all, haven’t we been doing it for thousands of years?