* Astronomy

Scientists find 'oldest human ancestor'

Researchers have discovered the earliest known ancestor of humans - along with a vast range of other species.
They say that fossilised traces of the 540-million-year-old creature are "exquisitely well preserved".
The microscopic sea animal is the earliest known step on the evolutionary path that led to fish and - eventually - to humans.
The research team says that Saccorhytus is the most primitive example of a category of animals called "deuterostomes" which are common ancestors of a broad range of species, including vertebrates (backboned animals).
Read more