Origin

The series begins on Isabela Island, where Attenborough observes a group of Galápagos tortoises wallowing in a mud pool near Volcán Alcedo. In this programme he addresses two questions; how the islands were formed and how they came to be populated with an unusual assortment of creatures. The first islands emerged 4 million years ago, formed as volcanoes rising from the ocean floor. A CGI sequence shows a 3D visualisation of the hotspot which lies beneath the Galápagos. Their isolation made colonisation by terrestrial mammals and amphibians almost impossible, but plants, invertebrates, birds and reptiles succeeded in establishing themselves. Plant seeds, spiderlings and other minibeasts were blown here on equatorial trade winds. Attenborough demonstrates how other invertebrates arrived by opening a piece of driftwood to reveal a carpenter bee larva. The islands lie at the confluence of three deep ocean currents which carry nutrients from across the Pacific and up into surface waters. These nutrients support a diverse food chain, from phytoplankton to scalloped hammerheads and humpback whales. The marine life in turn supports populations of sea lions, sea birds and Galápagos penguins. The physiology of reptiles enabled some individuals to survive the long crossing from South America on floating rafts of vegetation washed down rivers and out to sea. Thus, the island’s “cast of characters”, as Attenborough describes them, was assembled.