Great Human Race

Cat Bigney and Bill Schindler haul their reed boat up onto the shores of the river mouth to assess their next movements.

Bill and Cat look over their final destination, where the river they have followed from the desert finally meets the ocean.

Beringia may have been a more hospitable environment than continental lands in Siberia or Alaska, 15,000 years ago. Scientists have recovered pollen, insects, and plant remains from beneath the Bering Sea, suggesting that the first Native Americans would have encountered grassy plains lush enough to support megafauna, with woody shrubs for tools and fires.

Bill and Cat use their micro-Nubian spear tips to hunt a small desert mouse.

Bactrian camels live in the rocky cold deserts of Central and East Asia instead of the hot Sahara and have two humps instead of one like their cousins in Africa, the Arabian camel. They are the only truly wild camel left on earth, but their numbers have dwindled to less than 1,000.

Bill Schindler and Cat Bigney traverse rocky alpine terrain in the Bale Mountains.

Bill puts the final touches on a composite atlatl tip, heating pine pitch to glue small bladelets into an antler point.

Bill and Cat eat the full mouse they caught, charred and ground on a rock with bones and all.

Bill uses natural bowls in the rock face to boil hot rocks, heating river cobbles until they are red hot and then dropping them into the water to purify it.

Cat Bigney bites into a tuber that she's just dug up - water-rich, starchy plants growing deep under the ground.

Bill stokes the fire as the whole yak head rests in it, singeing off the hair and thawing it enough to crack into the skull.

Bill stokes the fire as the whole yak head rests in it, singeing off the hair and thawing it enough to crack into the skull.

Homo erectus experienced a pronounced increase in brain size. Almost 50 percent larger than that of the earlier human Australopithecus.