Evolution of morality

A common argument (or perhaps comment would be a better term) is that atheists cannot have morality, based on the fact that we have no god(s) to give it to use.  This, of course, is bupkis.

Ignore, for a second, the fact that all good parents teach their kids moral behaviour, and that society demands moral behaviour of us.  And while you're at it, ignore the numerous religions that either a) have no god(s), b) have god(s) as fallible as humans, or c) have a god and yet are the basis of much immorality. 

OK, the last one is ALL religions, but I digress.

Aside from the obvious illogic of the claim that you need to believe in god to be moral, there is a clear and concise answer as to why it is wrong - evolution.

Humans are what we scientists refer to as a social species - that is, a species that lives and functions largely as groups, rather than as individuals.  We are hardly unique in this - wolves, dogs, deer, chimps & other apes, dolphins & most whales, ants, termites, bees, horses, cows, sheep, goats, many kinds of birds, etc, are all examples of social species.

Organisms gain great evolutionary benefit from working as a social species - be it in the form of protection (a herd of deer is much safer against predators than is a lone animal), increased capture of food (wolf packs can take down large prey, single wolves are usually limited to small animals), sharing of resources, sharing of caring for the young, grooming to prevent disease, and so forth.

But not just any species can behave in a social manner - a species needs to evolve a series of traits - AKA morality - in order to function as a social species.  Without a "code of ethics" no social species can survive.  And the base of most/all human ethical systems can be seen in our social animal brethren.


Take for example, violent behaviour against others in your social group (herd, pack, tribe, workplace, etc).  This behaviour harms the group, by impairing or removing members of it.  This in turn costs the individuals in the group - both the individual(s) harmed by the violent behaviour, but everyone else as well (due to varying costs; decreased food acquisition, or the burden of caring for the injured).  Not too surprisingly, most social species have a strong bias against such behaviours.

The same can be seen in the cases of most of our moral behaviour - sharing resources without immediate payback (altruism) is common among all social animals.  Likewise, most social animals have the golden rule built-in (reciprocity, i.e. treating others well, in the expectation they treat you well as well) and a built-in punishment system for violations (usually ostritization or expulsion from the group).

Strange - despite not having gods, religions or bibles, animals have managed to come up with morality...

Now, given the apparent evolutionary basis for morality one would expect there to be a morality gene of some sort.  That's not entierly true - behavioural traits are almost always the product of multiple genes working together, and often involve disparate genes such as those responsible for brain structure, neuronal interconnectivity and hormonal levels.

None-the-less, morality genes have been identified, mostly in animals.  But at least one morality gene has been identified in humans - specifically monoamine oxidase, which when functioning normally prevents us humans from committing violent acts against each other.  Individuals carrying mutations in this gene are more likely to engage in violent behaviour.  Monoamine oxidase, when working properly, regulates violent behaviours by breaking down neurotransmitters.

As it turns out, there are a lot of mutations in monoamine oxidase, spread throughout the human population.  Exactly how all of these impact on our social behaviour is a bit of a mystery, but luckily its only a minor subset of those mutations that cause violent behaviour.

There is obviously a long ways to go until we understand the entirety of the biological basis for morality.  There are still many uncertainties as to how learned behaviour can compliment, enhance or counter our innate (genetic) morality.  Likewise, its unclear how much of these traits are uniquely evolved in humans (probably little-to-none), inherited from our ape ancestors (probably a goodly portion), or inherited from much more distant ancestors (probably a goodly portion as well).



And while there are a lot of open questions, on thing is clear - morality is not some magical pie-in-the-sky-gift-from-god.  Its as much a part of our evolutionarily-inherited biology as the colour of our eyes, or our pancreas.