The earliest known medicinal use of the coca plant - from which cocaine is made - has been pushed back by thousands of years.

A group of tourists in Peru catch a rare glimpse of a strange owlet that has not been seen for more than 25 years.

Africa could feed itself within a generation, and become a major agricultural exporter, claims a Harvard University professor.

Archaeologists on Orkney are investigating what is thought to be a 5,000-year-old tomb complex.

A £4.2m scheme to plant a million trees in urban areas over the next four years has been unveiled by the government.

The atmosphere of a relatively nearby extrasolar planet - just three times bigger than Earth - has been measured in a pioneering experiment.

A bacterium that uses arsenic in place of phosphorus breaks a golden rule of life on Earth, widening the scope of a hunt for life on other planets.

Temperatures reached record levels in several regions during 2010, the World Meteorological Organization (WMO) says, confirming the year is likely to be among the warmest three on record.