The fourth episode sees host Neil deGrasse Tyson exploring our eternal quest to end hunger and honoring Nikolai Ivanovic Vavilov, pioneer of modern plant breeding, who risked his life for a discovery that would change the history of science. Vavilov's story is marked by both the tenacity and creativity and is particularly tragic. Interwoven into Vavilov's somber narrative are warnings and treatments of science and its ethical implications, especially when science itself comes under attack from political forces.

In a provocative documentary, environmental campaigner George Monbiot examines the disastrous impact that farming animals for meat has had on the planet. He argues that the biggest problem driving us towards global disaster is how we feed ourselves, particularly on meat
George looks at alternative food sources, including synthetic meat, and a process that produces protein from just bacteria and air, and also explores revolutionary ideas that could change agriculture as we know it.

Two and a half thousand years ago, the Greek philosopher Socrates worried that the wide use of writing would have a negative impact on people's minds. He said that writing would create forgetfulness, because people will not use their memories. They would trust the external written characters and not remember themselves. In a world with an ever-growing tech industry, Michael Stevens tries to find out what effect technology has on our brains. He finds Technology isn't just changing our lives, it's changing our brains. In his experiments he tests what just 10 days of gaming does to things like our spatial memory.

Medical journalist Michael Mosley teams up with scientists whose latest research is turning common knowledge about fitness on its head. They reveal why 10,000 steps is just a marketing ploy and that two minutes of exercise is all a person needs each week. They discover how to get people to stick to their fitness plans and what exercise can actually make everyone more intelligent. Whether it is for couch potatoes who hate the thought of exercise, someone too busy to consider the gym, or even for fitness fanatics who are desperate to do more - science can help everyone exercise better.
By the end of January many people struggle to keep up their resolutions to be more active. The result is that people wastes millions on unused gym memberships. But new science has the answers.

They defined music and popular culture like no other band ever will - but how did The Beatles make the journey from Merseyside teenagers to international pop stars in the 1960s? Made on Merseyside - The Beatles discovers how American rock 'n' roll and rhythm and blues dragged post-war Liverpool into one of the most vibrant music cities ever with the Mersey Sound.
Featuring revealing interviews from those involved in the early years of The Beatles in Liverpool and Hamburg and unique archive, the incredible story of The Beatles' previous band formations and why it took so long for them to achieve success makes riveting viewing. From school bands, to colleges; Hamburg to The Cavern Club, The Beatles changed the world of pop music forever, but was Pete Best's sacking from the band and Ringo's replacement the final part of the jigsaw?

Well-known fans celebrate Stevie Wonder and his music by selecting some of his best-loved songs. Contributors include actor Martin Freeman, singers Alexander O'Neal, James Morrison, Beverley Knight and Corinne Bailey Rae, Gillian Gilbert and Stephen Morris, DJs Ana Matronic, Trevor Nelson and Norman Jay, journalist Sian Pattenden and presenter Emma Dabiri.
Stevie Wonder is one of the dominant figures in American music, a multi-faceted genius whose music has permeated popular culture, and he is not short of celebrity fans. His musical achievements are lauded in this anthology of his greatest hits.