At an individual level, it might not matter much. However, any modern society which bases major decisions on superstition rather than reality is heading for disaster
So your brother or mother is a creationist. Let them believe what they want, you might think. After all, it makes family get-togethers a lot easier and no difference to anyone else.
Or does it? Imagine if Mike Huckabee ends up as vice-president of the US – a mere heart attack away from the top job. Would you feel comfortable if the world’s biggest superpower was run by a man who rejects evolution, thanks to the support of tens of millions of people who also refuse to accept the truth?
Any leader who thinks evolution is a matter of belief is arguably unfit for office. How can someone who dismisses the staggering amount of evidence for evolution assembled by researchers in myriad fields possibly evaluate more subtle scientific evidence for, say, climate change?
What’s more, evolution is directly relevant to many policy decisions. Infectious diseases from tuberculosis to wheat rust are making a comeback as they evolve resistance to our defences. Antibiotic-resistant superbugs like MRSA are a growing problem. A deadly virus such as H5N1 bird flu or ebola might evolve the ability to spread from human to human at any time, leading to adevastating pandemic. It is not possible to grasp how serious these threats are and plan for them unless you understand the power of evolution.
There are many more subtle areas where understanding evolution matters too. For instance, fishing policies that allow fishermen to keep only large fish are actually leading to the evolution of smaller fish. The tremendous changes we are making to the environment are altering many species, from rats becoming resistant to poisons to urban birds changing their songs to counter noise pollution.
There is our future, too. Modern biology is on the brink of giving us previouslyunimaginable power over the human body, from reshaping embryos torewriting the genetic code and delaying the effects of ageing. Societies’ views on if and how these powers should be used will inevitably be shaped by people’s understanding of their evolutionary origins. Things look rather different depending whether you think we are a perfect, finished product or crude earlyprototypes thrown up by a desperately cruel process from whose clutches we now have to break free.
This is not to say that evolutionary theory tells us how to run societies (seeSurvival of the fittest justifies everyone for themselves) or make ethical decisions (see Accepting evolution undermines morality). It doesn’t. It is a descriptive science, not a prescriptive one. It does, however, help us to make informed decisions.