I also don’t understand why, if our existence does have a purpose beyond genetic replication, it took nearly 13.77 billion years for us to arise. What were deities up to for all this time? And why are we located in a rather pedestrian location in an average galaxy rather than at the universe’s centre? Surely a deity would have chosen a more glamorous bit of cosmic real estate? Given our tiny place in the vastness of the cosmos, it seems arrogant to suggest that life on Earth has been attributed some higher purpose. Are we as a species unique in being assigned a purpose? Or was each Neanderthal endowed with a purpose? Evidence suggests they had religion. Perhaps it was one of our earlier ape ancestors that God gave purpose? Or what about the first species to emerge from the sea to forge a life on dry land? Or the first bacterial cell? Perhaps all the living are special and given a purpose by a god, but that does not separate us from the rest of life.
The lack of a purpose-focused answer to the why-we-exist question does not mean we should live lives without meaning. I have chosen to spend my life trying to understand how I came to be, but this is a personal choice rather than one ordained. I have no doubt some reviewers will think I have wasted my time, but that doesn’t bother me as it was a choice I made. My life is not lessened by having no preordained purpose. On the contrary, I find the wonders of the universe significantly more inspiring than the story told in the Book of Genesis – the first book to attempt to tell the story of our existence. The fact that I am lucky to be alive does not diminish my enjoyment of my days on Earth.
One of the key reasons I abandoned my faith was the teaching that the Christian God was omnipotent and good. The existence of suffering, inequality and people such as Hitler and Lenin was impossible for me to reconcile with the God I had been taught about. To me, a better explanation for the horrors of the world is that they are not preordained. I developed a form of atheism that puts my existence down to chance and good fortune but which can also explain why suffering and bad behaviour exist.
If we are just another species, arising as a consequence of chance mutation and selection acting over billions of years, I wondered what it meant for humanity, morality and ethics. Our existence, if it is down to luck, does not mean humans, or you and me, are uninteresting and unimportant. On the contrary, humans are an unusual species, being the only one (on Earth at least) to have built cities, mastered fire, written novels and conducted scientific experiments. Our brains make us conscious, and this, coupled with our abilities to communicate complex ideas, to envisage possible futures and to trade off current actions with potential immediate and future consequences, sets us apart from the ants, anteaters and antlions. The ability to envision possible futures is important, in part because it brings with it the realization that our deaths are inevitable, and this in turn raises the question of why we exist.
The biological explanation of why we exist – to reproduce – at first glance lacks humanity. I exist for the same biological reason that all E. coli, earthworms and rose bushes do. My ancestors were successful at reproducing, and by definition my descendants require me to be good at it too. Where do ethics and morality come from given the reductionist explanation for existence I champion?
Part of the answer could be in who we choose to mate with, an idea initially proposed by Charles Darwin, the discoverer of evolution. If people tend to choose partners on aspects of their character that are determined, at least in part, by genes, as long as these more favourable partners have more children than everyone else, their desirable characteristics will become more prevalent in the population in future generations. Although far from conclusive, there is evidence that moral views can be heritable, so the fact that you are scrupulously honest while our past prime minister who delivered the Brexit agreement was less so may in part be due to genes.
There is no compelling evidence that people who are more honest, moral or ethical have more children. However, widespread access to birth control in countries where most of these studies have been conducted makes the study of the evolution of morality in modern societies challenging because the number of offspring a couple produces has become a matter of personal choice rather than genetic make-up. Nonetheless, perhaps our ancestors did have behavioural characteristics that differed from their peers who have no descendants living today.
There is another route via which morality and particular types of behaviour can evolve. We are a social species, living in groups. In most group-living species, it is important to be a group member, with solitary individuals often at risk of an early death, or of a failure to find a mate. A solitary meerkat, for example, is unlikely to survive for long. Throughout much of our evolutionary history, failure to be part of a group would have been risky, yet because we can communicate complicated ideas with one another and consider the future, groups of our ancestors could make decisions about membership. Individuals could be banished from groups, or even killed, if their actions were deemed unacceptable by the rest of the group, or even a powerful minority of it. If badly behaved individuals were more likely to be evicted from groups by our ancestors and meet an early death than those who exhibited less selfish behaviour, and if these bad behaviours were in part due to genetics, these behaviourally deleterious alleles would have become less common over time. In the last few years I have worked to help the community of biologists in my department in Oxford. Doing this has taken me away from research, something I enjoy. I did not make the decision to try to help researchers in my department because of a belief that I should do good. I did it because I felt I was in a position to help. I did enjoy building a stronger community of biologists. And I didn’t need to believe in a deity to sacrifice my research to try to help others.
We cannot solely blame genes for unethical or morally reprehensible behaviour. Like most of the phenotypic traits I have discussed in this book, environment can also play a role in their development. Some groups may be more accepting of certain types of behaviour than others, because the cost of certain behaviours to a group may differ depending upon where it lives. Stealing trinkets made from readily available seashells may have been tolerated by beach-dwelling groups, but if similar trinkets were stolen within groups that lived inland where shells were rare, these thefts could have been considered intolerable. I have chosen a relatively mild form of antisocial behaviour to make this point rather than focusing on more violent acts, yet similar arguments can be made for coercive and controlling behaviours. I did not wish to detract from the point I wished to make by focusing on a more shocking behaviour.
Evolution occasionally throws up abnormalities. I described earlier in the book how I have a genetic mutation that negatively impacts my eyesight. Extreme instances of any phenotypic traits determined by genes can arise through mutation, and this includes some forms of antisocial behaviour. Every now and again, individuals that do not adhere to standard cultural norms develop, with both genetic and environmental factors playing a role. For example, mutations in a gene called MAOA appear to be associated with psychopathic behaviour. I have no idea whether Charles Manson, Jack the Ripper and Vlad the Impaler were genetically predisposed to psychopathic behaviour, and even if they were this does not excuse the murders they committed, but it is possible that genetic mutations played a role in their dreadful crimes. There is speculation that Hitler, Stalin, Putin and other murderous dictators may also have had mental disorders.