Are Humans Now in Charge of Evolution?

After my public lectures on evolution, someone in the audience invariably asks, “Are we still evolving?” People want to know if humans are getting taller, smarter, better looking or more athletic. My answer is truthful but disappointing: We’re almost certainly evolving, but we don’t know in what direction or how fast. While some studies show that natural selection is acting on traits such as age of menopause (increasing), age at which first child is produced and blood cholesterol (both decreasing), this is hardly the stuff that excites futurists. And, regardless, there’s a critical difference here: Selection isn’t the same as evolution. Even if selection culls people with high cholesterol, unless those people are on average genetically different from those with lower cholesterol, we won’t see the genetic change over time that constitutes evolution. Human generations are long, evolution is slow, and so all we can say is that there’s the potential for evolution.