Green and vervet monkeys live on either side of Africa and their evolutionary paths diverged 3.5 million years ago, and yet the two species share a hard-wired vocabulary when faced with danger, clever experiments have shown.

It’s a puzzle that has perplexed scientists for years: humanity dumps millions of tonnes of plastics into the world’s oceans annually, yet almost all of it is swallowed up, with only a tiny fraction remaining visible on the surface.