In the decade since the genome editing capabilities of CRISPR-Cas9 emerged, research into novel medicines has boomed – but alongside progress comes new ethical considerations. Controversy erupted in 2018, when Chinese scientist He Jiankui created the first babies with edited genomes. After leaving prison last year, he’s now back in the lab trying to raise support for new research but refuses to discuss the ethical implications of his work. Dr Joy Zhang recently arranged a bioethics seminar and invited He Jiankui, it was the first time he’d agreed to engage with a global cohort of CRISPR scientists since returning to his research. Going back in time from cutting-edge to ancient technology, some of the oldest stone tools ever used by human ancestors have been unearthed at a fossil site in Kenya. Professor Tom Plummer talks us through the findings and how important the tools were in our evolution. And we immerse ourselves in the mysterious sounds of the Arctic and Antarctic, from singing ice to the man-made noises of oil and gas drilling. These dramatic soundscapes, created for the Polar Soundscapes project, showcase just how busy our oceans are. Dr Geraint Rhys Whittaker, composer and project lead, believes a novel approach may be required to prompt climate action. Yoga benefits our health in many ways, say the yogis, but which claims are backed up by science? Can yoga actually alleviate depression, fix lower-back pain or even reduce cardiovascular disease? Presenter Marnie Chesterton gets into her Lotus (position) and finds out first-hand at a class. Whilst in warrior one, she discusses the potential physical and mental health benefits of this ancient art of stretching, balance and movement with her class teacher. Returning from mat to studio, Marnie puts some of those claims to experts around the globe. She investigates the evidence to find out whether health boosting properties are the key to yoga's enduring popularity. Image Credit: Anthony Wallace Presenter: Roland Pease Producer: Harrison Lewis Assistant Producer: Sophie Ormiston