The reason you (probably - let's not make assumptions here) don't live by an African lake and feed mainly on fish may be a single, ancient mutation.
The discovery of a skull in a cave in Laos has pushed back the date of human migration into southern Asia by 20,000 years.
A detailed genetic analysis has settled the question of how and when the first Americans arrived in the continent.
Scientists say they've identified 'internal compass needles' in the noses of rainbow trout, helping explain the way many creatures can navigate using the Earth's magnetic field.
The La Niña weather pattern could be triggering flu pandemics such as 2009's swine flu, scientists suggest.
Warming oceans are triggering an enormous movement of marine species, say scientists, and could threaten North Atlantic fishing stocks.
People may be able to 'see' magnetic fields just as migrating birds do - or, at any rate, have once had the ability to do so in the past.