Talldwarf/Alamy
Why do we start growing copious amounts of ear, nose and eyebrow hair as we get older? How can this possibly help us survive in our twilight years?
David Muir
Edinburgh, UK
A mutation, or random change, in a gene can result in an inheritable characteristic that can be beneficial, harmful or neutral. A beneficial mutation may be successful, or “selected for”, and increase in a population. Harmful mutations would be “selected against”, a euphemistic way of saying that the carrier could be more likely to die or, at the very least, have little reproductive success. Natural selection doesn’t operate…
