This episode details the origins of the vertebrates, which lie in the primitive fish that once swam in ancient seas. Remarkable advances allowed them to make the radical move onto land, and then take to the skies with the advent of flight. Brand new discoveries of fossils - ancient and living - combined with stunning CGI enable David to chart their unexpected journey out of the water to populate all corners of the globe.
Totalling an estimated 10 million species, the insects and their close relatives are the most abundant and diverse group of animals in the world, so what is the secret of their success? Their hard external skeleton provides strength and protection and their small size allows them to exploit many microhabitats. In Yellowstone, Steve Backshall reveals how teamwork allows a colony of bees to scare off a hungry bear, and in Australia this same teamwork allows a colony of ants to beat the rising tide. But to unlock the real secret of their success Steve visits the Swiss Alps, where an incredible relationship exists between the ant, the wasp and the butterfly.
In the Gulf of Oman, survival is all about defense. Some species of sea urchins and sea slugs rely on toxins to keep predators at bay, while guitarfish use their size and armored bodies to stay off the menu. Peek into a little-known reef where fortune favors the bold and the well-prepared.