Earlier this month, in a medical first, surgeons from the University of Maryland transplanted a genetically altered pig heart into a living person. Doctors believed it was their only chance to save the life of David Bennett, a 57-year-old patient who was considered too ill for a human organ replacement. With hundreds of thousands of people worldwide in need of new organs, are animals set to be the future of transplantation? Ian Sample talks to bioethicist Prof Arthur Caplan about how the operation was made possible, and what could be next. Help support our independent journalism at theguardian.com/sciencepod

Could the food we eat and the air we breathe be damaging our immune systems? The number of people with autoimmune diseases, from rheumatoid arthritis to type 1 diabetes, began to increase around 40 years ago in the west. Now, some are also emerging in countries that had never seen the diseases before. Ian Sample speaks to genetic scientist and consultant gastroenterologist James Lee about how this points to what western lifestyles might be doing to our health, and how genetics could reveal exactly how our immune systems are malfunctioning. Help support our independent journalism at theguardian.com/sciencepod

The coronavirus variant has spread across the UK at incredible speed – but there are signs that the wave may have reached its peak. Madeleine Finlay talks to the Guardian science correspondent Nicola Davis about what we can expect in the weeks and months to come, and whether a second ‘exit wave’ could be here in the summer. Help support our independent journalism at theguardian.com/sciencepod

Last week, the tech CEO Elizabeth Holmes – once described as ‘the next Steve Jobs’ – was convicted of fraud, and could face decades in prison. Her now collapsed company, Theranos, promised to revolutionise medicine with a machine that could run hundreds of health tests on just a pinprick of blood. Those claims have since been exposed as false – but could they ever have been true? Madeleine Finlay speaks to the Guardian’s wealth correspondent, Rupert Neate, about Silicon Valley’s trial of the century, and pathologist Dr Benjamin Mazer about why Theranos’s vision seemed impossible from the start. Help support our independent journalism at theguardian.com/sciencepod

It’s been called the most important glacier in the world. The Thwaites glacier in Antarctica is the size of Florida, and contains enough water to raise sea levels by over half a metre. Over the past 30 years it has been melting at an increasing pace, and currently contributes 4% of annual global sea level rise. Ian Sample speaks to marine geophysicist Dr Rob Larter about a new research mission to the Thwaites glacier, the role of Boaty McBoatface and what it’s like to see a region melt away before your eyes. Help support our independent journalism at theguardian.com/sciencepod