With more than 7 billion members spread across the entire globe, the species Homo sapiens is one of the most successful species on the planet. Humans branched from the chimps around 6 million years ago and are now the only surviving member of an extensive human family tree. It was not always like this; until relatively recently Homo sapiens was one of several human species that roamed the Earth. Fossil evidence suggests that there are more than 20 hominids that make up the human family tree.

If we know that we are one of many human species this raises the question: What makes a human? We can recognise the earliest human remains due to several distinguishing features:

Large brain

Lightweight, bipedal skeleton

Skull with short base and high braincase

Small brow ridge

Chin on lower jaw

Whilst this allows us to distinguish the onset of anatomically modern humans, it requires more detailed palaeontology to distinguish the two greatest features of modern humans - culture and language.