In fact, once past the glossily superficial opening chapter "3 Billion Years in the Making" (essentially a highlights programme of what is to come), Titchmarsh turns out to be an excellent host, addressing the audience in his familiar chatty way and cleverly exploiting his horticultural roots, noting for example how evidence of major geological changes can be found in the most humble plant, wildflower or weed. And unlike his more academic predecessors, he also uses his TV charisma to the full, finding lighthearted ways of imparting otherwise dry information: sampling malt whiskies to explain how water permeates through different types of rock; scoffing platefuls of clotted cream with jam and scones to show how desert conditions millions of years ago gave Devon its fertile soil; or even getting made up as a Neanderthal and strolling down Oxford Street. It's all far more cosy than Attenborough.

The director of this eight-part series has clearly been watching Peter Jackson's The Lord of the Rings, as he never misses an opportunity for sweeping helicopter shots of snowy mountain peaks, rugged coastlines or glacial valleys. Combined with some neat computer graphics, the result makes ideal consumption for Sunday evening TV: easy on the eye and none too taxing on the brain, but informative enough to banish any fears of dumbing-down. --Mark Walker