BBC Four Tuesday

Ben Garrod explores how skin has evolved to animals to move in a range of habitats, allowing birds to fly, sharks to speed through water and sugar gliders to take to the air

Gareth and his wife Maureen Edwards head to St Davids, a place which holds half a lifetime of special memories for them.

Audrey relishes her role as county commissioner for the Girl Guides when she reprimands Richard for not sponsoring a fundraising event in aid of a new scout hut

Richard is disappointed with his birthday present - a pair of skis that Hyacinth intends to strap to the car in yet another attempt to impress the neighbours

Robert Bartlett examines the impact of the conquest of Britain and Ireland, and the methods used by William the Conqueror to keep the opposition at bay

The story of Kwame Brathwaite, the Harlem photographer, activist and cultural pioneer whose work helped define the iconic Black Is Beautiful movement

Part two of two. Professor Jim Al-Khalili meets the scientists attempting to capture and study dark matter, and finds out how dark energy might be tearing the universe apart

Ben Garrod explores how skin has evolved to animals to move in a range of habitats, allowing birds to fly, sharks to speed through water and sugar gliders to take to the air

Gareth and his wife Maureen Edwards head to St Davids, a place which holds half a lifetime of special memories for them.

Richard Miles investigates the rise and fall of the Roman empire, and learns how Christianity superseded the Roman multi-god belief system

Robert Bartlett examines the impact of the conquest of Britain and Ireland, and the methods used by William the Conqueror to keep the opposition at bay