BBC - Europe A Natural History - 2 - Ice Ages.avi

2.5 million years ago, a periodic shift in the Earth's orbit, coupled with a tilt in its axis, triggered a sudden change in climate and Europe was plunged into an ice age. The wintry iciness of today's Alps spread across northern Europe as ice sheets extended as far south as London, Amsterdam and Berlin. Conditions were ideal for cold-adapted animals, forerunners of musk oxen and reindeer. Woolly mammoth bones dredged from the bottom of the North Sea are evidence that this was once icy tundra. The warm interglacial periods attracted very different creatures: fossil hippos, rhinos, lions and hyenas have been unearthed in London. This thermal pulsing has occurred around twenty times, the last ice age ending 15,000 years ago. Europe now bears the scars of repeated glaciations. Lake Ladoga, Europe's largest freshwater body, is a product of the last thaw and has its own subspecies of seal as well as osprey, moose and beaver. Ibex are ice-age immigrants from Asia, stranded in the European mountains by the receding glaciers. Even the desert sand of Słowiński in Poland can be traced back to glacial debris washed up by the sea. As the ice retreated, the plants and animals associated with modern Europe began to advance north. Those featured include the capercaillie of the northern forests and migrant birds on Germany's wetlands. Modern humans began to settle the coasts alongside otters and seals, and slowly spread along inland waterways, but made little impression on the deciduous forests of the interior.