Anniversary send-offs

industrialising Britain of Darwin's day seemed a rather Malthusian one — less than half the children born in Liverpool in the mid-nineteenth century survived to the age of five, and overall life expectancy in the big cities was in the 30s, he said. " Today, the extraordinary and still accelerating growth of scientific understanding over the subsequent 150 years and its application to human health — especially over the last 50 years — has seen the global population increase sevenfold. " It is a startling fact that something like one in every 15 humans to have lived is alive today. And along with this surge in numbers is the increase in energy usage with substantial fluctuations above and below this figure in particular regions, he said. Most of this energy comes from burning fossil fuel. And, over the past four decades, the science-based green revolution has roughly doubled global food supplies using only 10 per cent more land. " The growth has more than matched population so that recent problems of hunger reflect inequitable distribution of food, not shortages as such. But there is a worrying sign that the green revolution is plateauing, whilst human numbers continue to grow, " May warns. Perhaps most disturbing are several studies suggesting the global demand for water — 70 per cent of it for agriculture — will exceed sustainable supplies somewhere around 2040, he says. All in all, this reveals the dramatic increase in the 'ecological footprint' of humanity upon the planet since the Origin of Species was first published, May said. " A variety of estimates — all of them unavoidably inprecise — suggest we are already exceeding the ecological footprint which Earth can sustain, " he said. One of the challenges has been how to model effective collaboration but it is receiving considerable attention, May said. Approaches to the problem use an array of metaphors — " for evolutionary biologists, the Prisoner's Dilemma; for ecologists, the Tragedy of the Commons; for economists, the Free Rider problem, " he said. Experiments using 'game theory' show that groups of people can achieve their goals if cheats and those who fail to pull their weight are punished. May believes an understanding of Darwin's third problem remains a key stumbling block. " At first glance the answer seems easy. You pay some small cost to gather a much larger cooperative benefit. For example, a prairie …