Three things to know:

There are things you should be very afraid of. According to security expert Juliette Kayyem, terrorism isn’t one of them.

One of Earth’s biggest mass extinction events was caused by blue-green algae farting out oxygen. Science writer Annalee Newitz tells us what we can learn from our planet’s turbulent history - and why the mass extinction we’re likely living through now is going to change everything for humans.

Our seeds are becoming less diverse. Conservationist Cary Fowler says this is something you should care about, if you consider eating crucial to your health.