A variety of malarial parasites have existed amongst the great apes for millennia, we look at how one of them jumped species and why humans became its preferred host.

We also look at why improved monitoring is changing our perceptions of earthquakes and follow the story of an endangered Polynesian snail.

What exactly is the relationship between mathematics and reality? That’s the impossibly difficult question we have been set this week by our listener Sergio in Peru. It’s one that’s been pondered by humans for millennia: the Greek philosopher Pythagoras believed “All is number”.

Is maths a human construct to help us make sense of reality - a tool, a model, a language? Does maths create its own reality? Or is it reality itself?

(Photo: A young gorilla. Credit: Hermes Images/AGF/Universal Images Group via Getty Images)