The Life Scientific Folgen

Tiny tree dwelling snails, partula, were so abundant across French Polynesia that garlands of partula shells would be presented to visitors to the islands. But when immunologist Dr Ann Clarke joined her husband, the late evolutionary biologist Professor Bryan Clarke, on expeditions to research the unique way this species had developed, a study in speciation turned, before their eyes, into a study of extinction. Ann witnessed first-hand the terrifying speed that biological controls, another mollusc introduced to kill a different, larger predatory snail, instead turned on Partula, and within a few short years, drove them to extinction in the wild. The subsequent scramble to save the species resulted in the launch of a global effort called The Frozen Ark to save the genetic resources of all animals which, like partula, face obliteration. The Frozen Ark was founded by Ann, her husband and the late Professor Ann MacLaren and with consortium members around the world, tissue and genetic material from threatened fauna is preserved as an ultimate animal conservation back-up. More than 48,000 samples have been collected by Frozen Ark members in zoos and natural history museums around the world from more than 5,500 different species. Frozen samples inform multiple captive breeding programmes, including at London Zoo, where descendants of partula rescued from extinction, are being bred ready for re-introduction back to their home in French Polynesia. And all this wasn't Ann's main career! As well as admitting to Jim that she was read bedtime stories as a child by the great JR Tolkien and that in her first ever job as a lab technician she helped Nobel Prize winner Sir John Gurdon with his nuclear transfer experiments, Ann also had a long and successful career as an immunologist and embryologist, fuelled by a life long interest in embryonic tolerance and immunity.

The food we eat is the greatest cause of death and illness worldwide. The main culprits - salt, sugar and fat - are now so embedded in our diet, in the form of processed foods, that most of us consume far too much.Yet Professor Graham MacGregor doesn't believe it's up to us to reverse this situation. It's up to the food industry, he says, who manufacture the processed foods, to take the 'rubbish' out. Now Professor of Cardiovascular Medicine at the Wolfson Institute of Preventative Medicine, Graham MacGregor has spent much of his career campaigning tirelessly to persuade the food industry to do just that - to reduce these demons in our diet - firstly salt, and now sugar.And he's had remarkable success. As a nation we now eat thirty thousand tonnes less salt each year than we did fifteen years ago, saving the NHS a staggering �1.5 billion per year.Blood pressure lies at the heart of this huge saving and, as Graham explains to Jim al-Khalili, blood pressure is not a natural consequence of ageing. High blood pressure is simply a consequence of too much salt. Producer: Beth Eastwood.

Professor Liz Sockett studies an extraordinary group of predatory bacteria. Bdellovibrio may be small but they kill other bacteria with ingenious and ruthless efficiency. Liz has devoted the last fifteen years of her career as a microbiologist to work out how this microscopic killer invades and consumes its victims - victims which include a host of disease-causing bacteria which have also acquired resistance to antibiotics which once killed them.As well as studying the numerous tricks and weapons which Bdellovibrio have evolved to despatch and feed on other bugs, Prof Sockett's lab at the University of Nottingham is also testing the bacteria's potential as a new kind of treatment in the era of antibiotic resistance. Deadly infections may not be able to outwit this bacterial top predator in the way they have with ever increasing numbers of antibiotic drugs.Liz talks to Jim Al-Khalili about how a BBC TV children's show first introduced her to the superfast killer bacteria, how Roman villas led her towards a life of discovery, and how her lab in Nottingham might be compared to the kitchen of a restaurant and her team to a brigade of chefs.Producer: Andrew Luck-Baker.