The notion of a dementia epidemic has been a big concern in ageing societies across the globe for some time. With the extension of life expectancy it seems to be an inevitable disaster – one of the “greatest enemies of humanity”, according to UK prime minister David Cameron.

It is often said that the first full image of the “blue planet”, taken by the Apollo 17 space mission in December 1972, revealed Earth to be precious, fragile and protected only by a wafer-thin atmospheric layer. It reinforced the imperative for better stewardship of our “only home”.

But there was another way of seeing the Earth revealed by those photographs. For some the image showed the Earth as a total object, a knowable system, and validated the belief that the planet is there to be used for our own ends.

For more than a century, researchers have tried to pin down exactly why so many animal species play in their infancy. Now a new study in wild macaque monkeys has found that infants who play more actually boost key motor skills. However, these skills are acquired at a cost. The researchers also discovered that active infants grow more slowly.

So what are the evolutionary reasons behind this trade-off? And should human parents who want tall children sit them in front of the TV rather than letting them play in the garden?

Based on the furor currently engulfing the US, you might imagine that the use of fetal tissue is illegal. But in fact the collection and use of cells obtained from a human fetus following miscarriage or abortion has a long history in medical science.

Rapid eye movements (REMs) during sleep may contribute to the visual part of our dreams by acting as a switch from image to image, researchers have found. The study, which measured the activity of individual cells in the brain in both awake and sleeping participants, is important because it is the first of its kind and provides a great starting point for uncovering the deeper secrets of human consciousness.

The latest dubious tactic of global soft-drink giant Coca-Cola has now been revealed for what it is - a move by an industry with a threatened financial future to confuse science, policy and the public, in order to buy time, and protect profits.