This week we look at xenophobic violence and investigate the science behind bias and discrimination.

We talk about the billions of bacteria that live inside us and the billions more waiting to pounce when you move to a new country. We also investigate how people move around Africa – today and thousands of years ago.

[soundcloud url=”https://api.soundcloud.com/tracks/190393997″ params=”auto_play=false&hide_related=false&show_comments=true&show_user=true&show_reposts=false&visual=true” width=”100%” height=”450″ iframe=”true” /]