Magnetic route home

• Sea turtles use the Earth's magnetic fields to navigate back to the area where they were born decades earlier, according to a study published recently in Current Biology. It used loggerhead turtle genetics to investigate their travels from nesting grounds in North Carolina and Florida to North Africa and back again. The new study suggests turtles learned their home beach's distinctive magnetic signature through geomagnetic imprinting.

High roller

• People who have offices on the higher floors of a highrise are more willing to take financial risks, a study in the Journal of Consumer Psychology found. Data from more than 3,000 hedge funds worldwide was analysed and the level of volatility of the fund was correlated with the floor the fund had its office on. It was found that the higher the storey, the more volatile the fund tended to be.

First finger

• The discovery of a fossil of a human finger bone, which is 85,000 years old, in the Saudi Arabian desert has challenged the traditional view that homo sapiens migrated out of Africa 60,000 years ago. This is the oldest specimen to be directly dated outside Africa and its doorstep, the Levant. Along with recent finds of 80,000-year-old human teeth from Asia and 65,000-year-old human relics from Australia, the Arabian finger bone provides further evidence that early modern humans spread out of Africa much earlier and farther than previously thought.