A new discovery of abstract symbolic drawings on a rock has been found in the Blombos Cave, about 300 km east of Cape Town in South Africa. The fragment - which some say looks a bit like a hashtag - puts the date of the earliest drawing at 73,000 years ago. As archaeologist Chris Henshilwood tells Adam Rutherford, the discovery is a "a prime indicator of modern cognition" in our species.

Nearly half the human genome contains genes that regulate what your organs should be doing at a specific time of day, This has enormous potential importance to the efficacy of drugs - what time of day you take them could be a real issue. John Hogenesch from Cincinnatti Children's Hospital has been studying the genes that cycle with our daily lives. His new database of cyclic genes could help plan the best timing for a host of therapeutic interventions

Physicist Helen Czerski has been in the Arctic for the last five weeks, aboard the Swedish research vessel and ice breaker Oden. As the expedition comes to a close we hear about the team's attempts to elucidate the driving forces behind the unusual weather patterns around the North Pole.

Inside Science has been profiling authors shortlisted for the prestigious Royal Society science book prize. This week it's mathematician Hannah Fry's new book, Hello World: How to be human in the Age of Machines. You can hear extracts from it on Book of the Week on Radio 4 all this week too.

Producer Adrian Washbourne.