In the south west of India lies the long narrow coastal state of Kerala. Most of its thirty-two million inhabitants live off the land and the ocean, … - David Attenborough

Reptiles and amphibians are sometimes thought of as primitive, dull and dimwitted. In fact, of course, they can be lethally fast, spectacularly beautiful, surprisingly affectionate and very sophisticated.

Make a list of all the environmental and social problems that today afflict us and our poor battered planet. – not just the extinction of species and animals and plants, that fifty years ago was the first signs of impending global disaster, but traffic congestion, oil prices, pressure on the health service, the growth of mega-cities, migration patterns, immigration policies, unemployment, the loss of arable land, desertification, famine, increasingly violent weather, the acidification of the oceans, the collapse of fish stocks, rising sea temperatures, the loss of rain forest. The list goes on and on. But they all share an underlying cause. Every one of these global problems, environmental as well as social becomes more difficult – and ultimately impossible - to solve with ever more people.

Penguins underwater look somewhat like dolphins, and indeed the two families have similar evolutionary histories. Dolphins are descended from air-breathing land animals, just as penguins are descended from air-breathing flying animals. Both subsequently took to swimming for their food. They became beautifully adapted and streamlined. And now, both are superlative swimmers and highly accomplished fishermen.