The recent discovery of an ancient bilaterian fossil

In March 2020, researchers in Australia announced the discovery of a 555 million-year-old fossil of a bilaterian animal, which they named Ikaria wariootia. The way that journalists presented this discovery made it clear that it is significant for… something. But it seemed to be difficult for them to pin down precisely what is significant about … Continue reading The recent discovery of an ancient bilaterian fossil

Contaminating space

In April, 2019, Israel's Beresheet spacecraft landed on crashed into the Moon. It later emerged that it was secretly carrying a supply of live tardigrades -- microscopic creatures known for their hardiness. Naturally, many observers, joking or not, brought up the idea of accidentally contaminating the Moon with destructive Earth life. I worry about a … Continue reading Contaminating space

Are humans descended from monkeys?

Are humans descended from monkeys? It's an interesting question. Too many well-meaning scientifically-minded individuals are quick to reply with a defensive "No! We just have a common ancestor!" But that's not a very good answer. It ignores the fact that the question is ambiguous, and that the definition of "monkey" is ambiguous. Sometimes the answer … Continue reading Are humans descended from monkeys?