African frogs haven't forgotten the ice ages. Scientists can tell by where they live.
Why are frogs diverse in some parts of Africa’s rainforests and less so in others? The patterns of cooling and glaciation during the last ice age would probably not have been your first answer or even your last-ditch guess, but it is, nonetheless, correct.
“When the glaciers were at their maximum global extent, the earth’s climate was cooler and drier, and forests that are continuous today contracted to what were essentially islands in a sea of savannah,” said Gregory Jongsma, the acting curator of Zoology at the New Brunswick Museum.
Jongsma is the lead author of a new study, conducted by researchers at the Florida Museum of Natural History and published in the journal Ecology and Evolution, which shows that even though it’s been 12,000 years since the last ice age, tropical African frogs still haven’t forgotten about it.
The study specifically focuses on the Lower Guinean Forests of Central Africa, part of what’s better known as the Guineo-Congolian rainforest or, more simply, the Congo. Centered around 0 degrees latitude, these forests are a visual representation of the planet’s obliquely unequal heating by the sun, which wrings water from the atmosphere like a damp rag onto the equator, creating a humid belt of jungle prominently bookended by deserts.