Early humans and Neanderthals had similar-sized brains but around 6 million years ago something happened that gave us the intellectual edge. The answer may lie in a tiny mutation in a single gene that meant more neurons could develop in a crucial part of the brain. Post-doctoral research scientist at the Max Plank Institute of Molecular Biology and Genetics, Anneline Pinson, did the heavy lifting on the research under the supervision of Wieland Huttner. They discuss with Roland how this finding offers a major development in our understanding of the evolutionary expansion of the all-important neocortex area of the brain.

A central aspect of what it is to be human and how we use our intelligence is to care for one another. A burial site in Borneo from tens of thousands of years ago gives us fresh insights into how advanced our capacity to care was, millennia before the establishment of stable communities and agricultural life. Remains uncovered by a team of archaeologists from Australia have found one of the first examples of complex medical surgery.

Finally, moving to a carbon-neutral society will involve developing huge battery potential, but that comes with its own environmental and social problems. Could a solution be found in the exoskeleton of crabs?

Mathematics and our ability to describe the world in terms of number, shape and measurement may feel like a uniquely human ability. But is it really? Listener Mamadu from Sierra Leone wants to know: can animals count too? CrowdScience presenter Marnie Chesterton goes on a hunt to uncover the numerical abilities of the animal kingdom. Can wild lions compare different numbers? Can you teach bees to recognise and choose specific amounts? And if the answer is yes, how do they do it? Marnie tries to find out just how deep the numerical rabbit hole goes… and comes across a parrot named Alex who is perhaps the most impressive example of animal counting of them all.

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