Discover the evolutionary secrets of some of the world’s most majestic creatures. From voracious crocodiles and acrobatic birds to stupendous whales and majestic elephants, WHEN WHALES WALKED follows top scientists on a global adventure as they follow clues from the fossil record and change what we thought we knew about the evolution of iconic beasts.
It may take two to make a baby - but not necessarily two to bring it up. So what makes a parent decide to stay or go? Especially if that parent is a dad. From the California mouse mother who has to kickstart her partner's paternal instincts, to Adelie penguin parents who can't leave their eggs alone for five minutes; from cheetah mums practicing promiscuity to keep the dads on side, to flamingo parents both producing milk for their young. We see just how far these incredible parents go in order to protect and nurture as many offspring as possible through to adulthood.
The hunt for life within the long-dead bones of dinosaurs may sound like the stuff of Hollywood fantasy - but one woman has found traces of life within the fossilised bones of a T rex. Dr Mary Schweitzer has seen the remains of red blood cells and touched the soft tissue of an animal that died 68 million years ago. Most excitingly of all, she believes she may just have found signs of DNA. Her work is revolutionising our understanding of these iconic beasts.
The final episode explores dinosaurs' extraordinary ability to survive. Featured dinosaurs include the bizarre magyarosaurus, which lived in the shadow of the biggest flying animal - hatzegopteryx - and showed an amazing adaptation to island life; and the weird nothronychus, a carnivore that gave up meat eating. This astonishing capacity to evolve into ever more diverse and bizarre forms meant that dinosaurs not only spread throughout the world, but also dominated life upon it for more than 160 million years. It was only an unprecedented extraterrestrial event that finally saw the end of planet dinosaur.
In the penultimate episode, David Attenborough looks at monkeys. This group started its life in the tree-tops and this is where we join the capuchin, whose acute vision and lively intelligence helps them find clams in the mangrove swamps of Costa Rica and crack them open on tree-anvils. The swamps are also full of biting insects, but the monkeys rub themselves with a special plant that repels them.
When you picture the lowest levels of the food chain, you might imagine herbivores happily munching on lush, living green plants. But this idyllic image leaves out a huge (and slightly less appetizing) source of nourishment: dead stuff. John C. Moore details the "brown food chain," explaining how such unlikely delicacies as pond scum and animal poop contribute enormous amounts of energy to our ecosystems.