Could Adam's descendents be living in Africa?

Wells, a National Geographic explorer in residence, has embarked on a global genetic odyssey using the latest in DNA testing technology.

His quest is to understand how humans spread throughout the world tens of thousands of years ago. He also wants to discover more about a man who existed during the last Ice Age and is the grandfather, many times removed, to millions of men today.

These men have fragments of DNA that can be traced to an individual given the name Adam. He lived somewhere in Southern Africa at a time when mammoths roamed the Earth, and humans eked out a living hunting and gathering.

Soon, however, you will be able to meet Adam - on TV, that is. The National Geographic Channel will next week be airing the show, DNA Mystery: The Search for Adam.

During the show, Wells will be introducing not only Adam but also explaining The Genographic Project, which he recently launched in partnership with National Geographic and IBM.

It is an ambitious project that aims to collect and analyse the DNA from more than 100 000 indigenous people from around the world. Those interested in finding out more about their genetic past can also take part.

By paying a fee they can have their DNA analysed.

"The project is to focus on reconstructing how humans moved around the world, to tell of their migratory routes," Wells said last week.

One of the indigenous groups Wells and his colleagues are studying are the Toubou, who live in the Sahara Desert.

"With the Toubou we are hoping to find out who were the first people to settle in the Sahara," explained Wells.

But it is in Southern Africa that Wells has a particular interest. It is here that Adam has left a lasting legacy: he sprouted the oldest discovered DNA lineage.

"We believe that some of Adam's characteristics can still be seen in Southern Africa but we need to find out what they are," Wells explained.

Previous research has shown that groups of the San are the most closely related to Adam. It is believed that Adam probably had a lot of the physical characteristics of the San.

"His skin was probably not that dark, nor was he that muscular," Wells said.

Adam was discovered through the study of Y-chromosome DNA, a particular type of genetic coding uniquely male, being passed from father to son.

As the Y-chromosome DNA passes through generation after generation, it undergoes slight changes, but nothing as drastic as other types of DNA.

"The pieces of DNA you find in the Y-chromosome don't go through the same shuffling process that other DNA undergoes, so it is easier to trace," Wells pointed out.

Wells believes there are two reasons why Adam's DNA still exists today: either he was extremely lucky or he was extremely tough and resourceful - a super-Alpha male.

But Adam lived in a world that was no Garden of Eden.

"It was tough going. His world was in the grips of the last Ice Age. In Southern Africa it was drier than now, water was difficult to obtain and so were animals," Wells said.

To make matters worse, genetic evidence suggests that humankind went through some sort of "bottleneck" around the time Adam roamed the grassy plains.

Scientists have suggested the bottleneck was caused by some catastrophe that dramatically reduced the human population to maybe as few as 2 000 individuals. Likely culprits could have been disease or a massive volcanic eruption.

All this helped, believes Wells, to mould Adam into an ultimate survivor, a trait he passed on to his descendants.

"He would have had to been smarter. Maybe there was a change of behaviour, a great leap forward, that gave him better skills to survive. Maybe it was new tools that helped his descendants to leave Africa," he surmises.

It was these skills, said Wells, that allowed Adam to set off on a journey that was ultimately to see his descendants carrying his genes to every corner of the Earth.