Adam Rutherford examines a new study published this week which reveals how a megaflood and giant waterfalls severed our connection to what is now France, resulting in the creation of island Britain and the watery moat of the English Channel. Jenny Collier of Imperial College London uncovers the ancient evidence dating back 450 000 years ago.

The dream of unbroken sleep is a complex interaction between our environment and our genes, and new research is a step towards understanding the genetics of sleeping patterns. Jason Gerstner of Washington State University discusses his isolation of a gene that seems to play a crucial role in sleep across a number of species including humans.

Turi King played a pivotal role in the identification of Richard III from bones discovered in a Leicester car park She's now involved in another infamous cold case - that of Jack the Ripper. Her interest is in the last of his five canonical victims, known as Mary Kelly, and she's authored a commissioned report on the possibility of identifying the body of Mary Kelly using DNA.

And Paul Smith from Gardens Conservation International discusses the new Global Tree Survey - the biggest and the most comprehensive database of all the trees in the world - accumulated from 500 papers, and nearly four centuries of dendrology.

Producer Adrian Washbourne.