Over the course of the Earth's history, there have been at least five major extinction events -- the End Ordovician, Late Devonian, End Permian, End Triassic, and End Cretaceous. Some ecologists, citing the loss of biodiversity in certain areas and the species at risk, say that a new major extinction event could be on the horizon. Writing this week in the journal Science, researchers say that warming temperatures could cause one-fifth of the world's lizard species to become extinct by the year 2080.
In this hour, we'll talk about modern extinctions and what causes them. How much is human activity to blame? Plus, we'll check in with researchers studying a fungal infection that has devastated frog populations in some parts of the world.
Produced by Christopher Intagliata, Senior Producer