Darwin’s theory of evolution generates almost as much suspicion today as it did when it first appeared in the nineteenth century.
The theory has two main components, and there are two corresponding sorts of unease about it. The first component is natural selection, in which organisms are shaped by environmental pressures. The second is sexual selection, in which organisms are shaped by the choices of potential sexual partners.
The first component of Darwin’s theory undermines the assumption of a cosmic designer, so the first sort of unease tends to be felt by people who have traditional religious beliefs. Notice, though, that natural selection doesn’t really undermine the looser idea that living things are shaped in an appropriate way for living in their environments. In a metaphorical sense they are “designed”, although they are not literally designed by a conscious or intelligent designer with a plan. The “watchmaker” is “blind”, in Dawkins’ metaphor, but he is still a bit like a watchmaker. Examples of convergent evolution (think of similarities between marsupial moles and placental moles) illustrate how environmental niches shape the living things that inhabit them: similar niches can shape their inhabitants in strikingly similar ways.
The second component of Darwin’s theory is quite different. If natural selection is all about “fitting in with the environment”, sexual selection is all about “standing out from the crowd”. Far from working towards a smoother or more economical fit between organism and environment, sexual selection introduces capricious extravagance. If natural selection makes for traits that are “sensible and practical”, sexual selection makes for traits that are “crazy and impractical”.
With sexual selection comes ostentatious ornamentation, “runaway” emphasis on arbitrary traits, advertising, “handicapping” to subvert false advertising, prodigious waste, ritual, and romance, among other things. Ironically, as intelligence — or at least choice — is an essential part of sexual selection, it tends to introduce features that are “stupid” inasmuch as they are unsuited to the environment, and “irrational” inasmuch as they are harmful to the individuals who have them. (So much for the nearest thing nature has to “intelligent designl”!) Some specific traits (such as the Irish elk’s gigantic antlers) no doubt contribute to the extinction of the entire species.
Darwin used the word ‘man’ (meaning mankind) in the title of his main work on sexual selection, because he recognised its importance for understanding the evolution of our own species. The idiosyncrasies of human behaviour, culture and art are more complicated than those of bower birds, but they are similar in that their main engine is usually sexual selection. We too should recognise its importance, and the relevance of evolutionary theory for our self-understanding as humans.
In the nineteenth century, delicate sensibilities and Victorian piety were offended by Darwinism. In the present day, delicate sensibilities and twenty-first century piety are still offended. Our pieties are moral rather than religious, and take the form of strong distastes for beliefs that can be construed as misogynistic, sexist, racist, or homophobic. Such beliefs as that men and women have innately different intellectual strengths, say, or that rape can be explained from an evolutionary perspective, say, are frowned upon in our day as much as atheism was in Darwin’s day. The hierarchical institutions which discourage such thoughts are no longer those of the church, but of academia.
Darwin still has the power to offend. A widespread reaction is to suppose that Darwin’s theory doesn’t apply to humans at all. We say that “humans are no longer evolving”, or that “human culture overrides human nature”, or that “our minds are wholly the products of environment”, or even that “there is no such thing as human nature”. Recently, a neuroscientist claimed that “male and female brains only differ because of the relentless ‘drip, drip, drip’ of gender stereotyping”.
But that is all wrong. Rather than yielding to pressure to avoid offence, or promoting a dishonest political agenda, we should stop frowning upon “impious thoughts” and instead try to avoid immoral actions. Misogyny, sexism, homophobia and racism are best understood not as “having the wrong beliefs” but as willingness to behave in ways that disregard interests because of group-membership. They’re morally wrong, often extremely so, but not because of anything like impiety.