Crowdscience

What evidence is there for a semi-aquatic period in human evolutionary history? That’s the question that’s been bothering listener Dave in Thailand. He thinks our lack of hair and love of water might indicate that, at some point, we were more water-based than we are now. But what does science have to say on the matter? The theory that our ape ancestors returned to the water for a phase in our evolutionary history is a controversial idea that most scientists disagree with. Anand Jagatia chats to Dr Melissa Ilardo, assistant professor at the University of Utah, about our dive reflex - a physiological response we display when submerged underwater, which helps direct oxygen towards vital organs. But this is not a response that is unique to humans - it is found in all mammals. Experts say it developed long before all apes split off in the evolutionary tree. To find out more about the theory itself Anand hears from John Langdon, emeritus professor at the University of Indianapolis. He explains why the aquatic ap