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Theories of Evolution
About 30 miles north of Hay is the spa town of Llandrindod Wells, built after the enclosure act in the early 1840s. One young surveyor working in the area was Alfred Russel Wallace. 10 years later he travelled through the Malay Archipelago working as a naturalist collecting specimens for sale and study. He came up with a theory for how such diverse life forms might have evolved and sent his ideas in a letter to Charles Darwin.

Darwin himself had studied geology in the Welsh hills just before his voyage on the Beagle. Realising that Wallace had a very similar theory to his own, Darwin rushed ahead to publish his famous book On the Origin of Species.

Wallace never seems to have resented Darwin’s fame and he himself became more and more interested in spiritualism. Geneticist Steve Jones and science communicator Stephen Webster take a walk in the country that Wallace once knew and discuss his contribution.

Universe or Multiverse?
Evolution may explain how we got here but an altogether bigger question is why are we here at all? Quentin Cooper is joined by Lord Rees, Astronomer Royal and President of the Royal Society, and by cosmologist Bernard Carr to discuss what our own presence tells us about the nature of the universe.

It turns out that, if any one of about 19 different fundamental constants of physics was even slightly different from its measured value, we would not be here. Stars might not form; They might not cook elements such as carbon and oxygen and spew them out to form planets; They might not live long enough nor shine sufficiently constantly to give life a chance to develop on those planets.

In fact, it seems remarkable that we are here at all. There would only seem to be two possible explanations. The first is a theological argument – perhaps the constants of nature are determined by some deeper level of physics, perhaps even by God. The second appeals to atheists but seems even more incredible – our universe is just one bubble in a vast multiverse of possible worlds and of course the one we are in seems tuned for life because that is the only sort that would produce observers to wonder at it.