The way the body can track the passing of the seasons in a "chemical calendar" has been discovered by scientists.
At least 717 people taking part in the Hajj pilgrimage have been killed in a stampede near the Islamic holy city of Mecca, Saudi officials say.
The scandal over VW cheating pollution emissions tests in the US is casting a cloud over the whole car industry.
A study showing that nearly all mammals take the same amount of time to urinate wins one of the 2015 Ig Nobel prizes.
Scientists in South Africa have discovered a new human-like species, which could change ideas about our early relatives.