If you traced your family tree back 185 million generations, you wouldn't be looking at a human, a primate, or even a mammal. You'd be looking at a fish. So where along that line does the first human show up? The answer may surprise you.
As the expedition team near the end of their journey across Micronesia, it's a race against time for the extreme deep divers as they continue their search for new species. As Kate Humble explores the Rock Islands of Palau, Mike DeGruy embarks on a unique training programme. The Newtsuit is an incredible feat of submarine engineering - a bright yellow one-man submersible that Mike has to master before he can venture even deeper into the Pacific abyss.
The big blue is the world's greatest wilderness, far from shore and many kilometres deep. It's a vast marine desert where there is little to eat and nowhere to hide. Yet it's home to some of the biggest and most spectacular creatures on earth. This episode reveals what it takes to survive in this savage and forbidding world. We witness feats of incredible endurance, moments of high drama and extraordinary acts of heart-wrenching self-sacrifice. Every animal in the big blue must find their own unique way to survive.
The documentary series gives a bird's-eye view of South America, as condors soar along the Andes, scarlet macaws explore the heart of the Amazon and hummingbirds and vultures see the continent's greatest sights. It is a journey that includes Machu Picchu, the Nasca Lines and the cities of Rio de Janeiro and Santiago. In Patagonia, giant petrels shadow killer whales as they hunt seals by stranding their huge bodies on the beach. At Iguassu Falls, dusky swifts dive through the cascades to huddle in communal roosts while hummingbirds bathe below. In a secret Andean location, condors soar in flocks over 40-strong and scavenge on casualties from herds of fighting guanacos. Elsewhere, a mother condor gently pushes her youngster to the edge of a 200-metre cliff, as flight school begins. Deep in the Amazon, macaws seek medicinal clay. They are joined by a host of secretive jungle animals, including spider monkeys and tapirs, all after the same remedy. In Peru, condors soar over fighting sealions waiting for casualities and on a mass exodus north, birds converge on the Panama Canal. In Costa Rica, black vultures descend on turtles as they lay their eggs in the sand and pick off the eggs that ping-pong through the air.
With scientist Kerisha Kntayya, Judi joins a crocodile hunt with a difference. Kerisha plucks young crocodiles out of the water. Judi then joins Kerisha's team as they wrestle an adult croc as part of the study Kerisha hopes will help save these prehistoric creatures. Judi, who's had a fascination with bats from an early age, also explores the Gomantong cave, home to more than a million bats.