As often happens in science, technology has opened up a field to new ways of solving old riddles – often providing startling answers.

Taken with the archaeological data, we can say that the old hypothesis of an invasion of people – not merely their language – from the steppe appears to be true.

Every drop of human blood contains a history book written in the language of our genes.

The greatest history book ever written is the one hidden in our DNA.

DNA ties us all together; we share ancestry with barracuda and bacteria and mushrooms, if you go far enough back.

We are all Africans under the skin.

Taken with the archaeological data, we can say that the old hypothesis of an invasion of people - not merely their language - from the steppe appears to be true.

So what we can answer [as geneticists] is questions about biology, about biological ancestry. But to make any sense of that historically we have to contextualize it -- the archaeology, the linguistic pattern, even the climatology.

Imagine you're copying a very long document, and occasionally you'll put an A where there should be a C. And that mistake has been translated down through the generations, and more mistakes have accumulated. So the longer the lineage has been in existence, the more mistakes the sequence is going to have.

If you go far enough back, your genome connects you with bacteria, butterflies, and barracuda - the great chain of being linked together through DNA.