This week's programme presented by Andrew Luck-Baker.

Take one tiny fragment of bone found in a cave in the Altai mountains of southern Siberia. Extract and analyse the mitochondrial DNA – that's the genetic material which is inherited through female lines – and discover, a possibly, entirely new hominid which shared the Earth around 50,000 years ago with the ancestors of us, modern humans, Neanderthals and the Hobbit found on the Javan island of Flores.

There may be only 120 of them left in the wild - one of the world's most endangered tortoises – the Egyptian Tortoise is being threatened by climate change, habitat destruction and the illegal pet trade. The Zaranik Conservation Programme is using local Bedouin volunteers, with their intimate knowledge of the area and well-honed tracking skills to find the few remaining animals.

Ten years ago, a severe cyclone led to massive, devastating floods in Mozambique in Southern Africa. At the time the national rescue effort and international assistance was hampered by the political turmoil the country was under. But now, a new centre has been set up to monitor and improve the response to a number of natural disasters.

Obesity is a growing problem around the world. One possible cause is that we're eating too much of the wrong types of food. Portion sizes have been increasing, but when did we start piling up our plates? One way to find out was to look at paintings of meals from the past. So the researchers chose paintings of the much-depicted Last Supper – in Christian belief, this was Jesus Christ's last meal before he was crucified. He shared bread and wine with his disciples. And over time, sure enough the amount of bread and the size of the plates, starts to grow.

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28 minutes

Last on

Sun 28 Mar 2010 04:32 GMT

Gravitational Waves

'Ripples' from black holes detected

Gravity and ripples in the fabric of space time - what do these mean for us?