According to my rationale, many things must be considered to establish a healthy understanding of war. I’ll only touch on the aspects from a biological standpoint and try to leave philosophy and metaphysics aside. At the top of the pile of reasons sits the distinction between the natural and cultural changes of our species. Natural selection (evolution) moves on a timescale measured in groups of generations lasting anywhere from hundreds to thousands of years for significant changes in morphology to accumulate.
Cultural change (also termed “cultural evolution”, although I don’t particularly like that term as it diffuses the intellectual waters and breaks down the intrinsic meaning of the word) works on a scale that in comparison must appear to a visitor from Mars to be light-speed. As our technology has changed, so has our culture and society, leading many to false impressions and expectations about some of our deepest questions. For instance, quite a few people are boggled as to why the expression of violence through war (and individually) still shadows our advanced cultures in this, the enlightened 21st Century. They rhetorically say that since we’ve “come so far” in human historical terms then we should have already shed such primitive behaviors as war and religion. You have heard this line of thinking? But I and others think they are misled, and I will try to show why.
Humans are still actively evolving creatures. This is in no doubt since the examination of the human genome shows clearly that this is the case. However, we evolve significantly now at much slower rates due mainly to our advances in medicine and massive gene pool reserves. Humans haven’t really changed the rules of natural selection. We might think that because we have culture – and with it all kinds of medical interventions and technologies – that we are immune from natural selection, but nature proceeds as usual. Evolution is defined as a change in gene frequencies over time, which means that over generations, there will be changes in the gene pool, and humans experience those changes as much as any other organism. Some people live, and some people die, and some people pass on more genes than others. Therefore there is a change in the gene pool over time.
But we might suggest that, with all the cultural and technological innovation, there would be some kind of influence in composition of the gene pool, and there is. Take smallpox, for an example. Years ago millions of people died from smallpox, and their genes were not passed on because they died before reaching reproductive age. The human gene pool was then missing the genes of those people. But now, since smallpox has been wiped off the planet, people who would normally have died of the disease now live, probably have children, and thus contribute to the human gene pool. In another example, the birthrate always goes down the more developed and economically affluent countries become. Today the highest birth rates are in Africa, Latin America, and Asia. People in these areas are now the major contributors to the human gene pool. In many generations, the human species will be composed more of genes from those groups than from developed countries.
How does this help explain war? Humans and other species do not function on a Lamarkian evolutionary program in which arbitrarily desired traits are selected for and passed down (evolution would go gangbusters if it worked like this). Rather the more sedate Mendelian process of acquired traits through natural selection dictates what successive generations will receive. In other words, the preferred characteristics in the future may not be selected for because the present conditions demand other characteristic selection (or, it’s getting colder so those mammoth ancestors with hairier bodies survive better than those more naked, passing down their bias of hair to future generations. No thought process like, “in 40,000 years we mammoths may need to have transparent hairs in order to both stay warm during winter and reflect light during summer therefore we’ll start evolving that trait now”, natural selection does work this way [Lamarkian], it is unguided and unconscious.)
In early proto-human family groups in Africa, certain traits were selected for that we still retain today. In fact most of them are still embedded in our genome. The climatic knife-edge of the African environment very nearly threw our young species onto the great scrap-heap of extinction along with 99% of all species that has ever lived on this earth. Our existence today comes through a bottle-neck of sorts that determines the fact that all “races” share a common ancestor (indeed the designation of ‘race’ for human groups is outdated and frankly incorrect; you, I and all people are essentially identical and I refuse to delineate races). These traits include the tendency to violence, the altruistic nature of love, the overwhelming desire to live and not perish, and myriad other characteristics. War is included for the simple reason that as these humans broke into family groups and began to depart from Africa they needed to protect certain things.
Resource control is a huge factor in any modern conflict and this goes for our ancestors equally. Their cultures were based around a ‘slash and burn’ nomadic stripe that relied on the small percentage of land that houses game. 70% of the planet is covered in uninhabitable water and a large percentage of land is inhospitable, therefore the choices for hunting and living are few, creating tensions that still exist today. As these groups coalesced into more agrarian cultures, the need to defend and acquire arable land began to lead to more and more frequent wars. This trait for war has not been given enough time in our collective culture to be selected against by evolution, in the same way that altruistic love and the need for in-group acceptance are still around, meaning that war and violence still holds a useful function in our species. Alternatively, evolution has perhaps not been given enough time to select against war because the speed at which attitudes and society has changed places impossible pressures on the gradual process of Mendelian evolution, and our wants and desires fall on the deaf ears of biological evolution.