When Indonesia’s Mount Toba blew its top some 74,000 years ago, an apocalyptic scenario ensued: Tons of ash and debris entered the atmosphere, coating the planet in ash for 2 weeks straight and sending global temperatures plummeting. Despite the worldwide destruction, humans survived. Sarah Crespi talks with Online News Editor Catherine Matacic about how life after Toba was even possible—were humans decimated, or did they rally in the face of a suddenly extra hostile planet?

Next, Julia Buck of the University of California, Santa Barbara, joins Sarah to discuss her Science commentary piece on landscapes of disgust. You may have heard of a landscape of fear—how a predator can influence an ecosystem not just by eating its prey, but also by introducing fear into the system, changing the behavior of many organisms. Buck and colleagues write about how disgust can operate in a similar way: Animals protect themselves from parasites and infection by avoiding disgusting things such as dead animals of the same species or those with disease.

This week’s episode was edited by Podigy.

Listen to previous podcasts.

[Image: Emma Forsber/Flickr; Music: Jeffrey Cook]