The ABC's screening of the BBC's Human Journey, a documentary series chronicling the emergence of humans out of Africa 70,000 years ago, represents, for me, a milestone in documentary TV. I must be in the market for a cardigan and slippers but, then again, a lot of people will find something unique in this astonishingly interesting series of programs.

Most importantly, the DNA record shows that all ethnicities living outside Africa today stem from a single group of adventurers who crossed the Strait of Hormuz at the mouth of the Persian Gulf all those millennia ago.

Some ethnic groups dispute this as it contradicts local creation myths.

But the chemical record cannot be denied. It's tremendously important to know this, as it signals a community of such incredible diversity that underscores the vast stretches of time that has passed since the African exodus. And it tells us that we have a lot in common.

What I'd like to see now, as a committed cardigan-and-slipper, armchair scientist, is the DNA heritage chart published - somewhere. This chart shows which strains of humanity arrived outside Africa, and when. It stands as a powerful testament to modern science and a reminder of our common heritage.

Not only DNA, but stones and bones, as well, are used in the program to puzzle out an itinerary. Plus massive amounts of climate science. Where did all this research come from? How do we know, for example, that the Bering Sea was once a land mass?

For those who, like me, are curious about our origins, Human Journey is a fantastic way to spend a few hours of an evening. Now, where's my pipe?