AllMovie

Charting paleontologists' search to "fill in the evolutionary sequence from water to land," says narrator Peter Thomas. The "gap" lasted some 20 million years, but this hour spans 120, beginning with the find of a tetrapod fossil on Canada's Gaspe Peninsula in 1881. Other stops include Greenland, Latvia, South Africa and a sandstone formation in Pennsylvania. But 400 million years ago it was a swamp (perhaps the world's first)---a perfect spot for evolutionary "tinkering," says the University of Chicago's Neil Shubin. The result, as Thomas puts it, was "a happy accident."