Air date: 2016-03-25

Runtime: 22 min

There are many fine examples of evolutionary history in the natural world. Whales evolved from land-dwelling creatures to today's marine mammals.

Air date: 2016-04-01

Runtime: 22 min

The leopard is perhaps the best-equipped big cat, with a population spread far and wide, but lions have almost no predators.

Air date: 2016-04-01

Runtime: 22 min

Desert animals have evolved to handle heat and lack of water. This includes scorpions, which have existed since life first crawled from the sea.

Air date: 2016-04-01

Runtime: 22 min

The African Savannah sees thousands of battles each day. How do elephants survive on a diet that even the strictest vegetarian would avoid?

Air date: 2016-04-08

Runtime: 22 min

Males and females of some species fight viciously. Though they are usually not trying to kill each other, the fighting can result in death.

Air date: 2016-04-08

Runtime: 22 min

With predators always looking for a meal, their prey must constantly avoid being eaten. Defensive adaptations add to their chances of survival.

Air date: 2016-04-08

Runtime: 22 min

Attack and escape scenarios involving avian predators and their prey, including horizontal speeding and diving to avoid capture.

Air date: 2016-04-15

Runtime: 22 min

Crocodiles are descended from animals that roamed Earth 250 million years ago, while snakes rely on the sun to control their temperature.

Air date: 2016-04-15

Runtime: 22 min

From insects that look like leaves and snakes that play dead to flying fish and poisonous toads, animals defend themselves in fascinating ways.

Air date: 2016-04-15

Runtime: 22 min

Almost all animals living in the sea have bodies designed for hunting or protection, and predators have adapted extreme measures to survive.

Air date: 2016-04-22

Runtime: 22 min

Protecting themselves underwater is a matter of invention and reinvention, so aquatic animals deploy an array of strategies just to stay alive.

Air date: 2016-04-22

Runtime: 22 min

Protecting themselves underwater is a matter of invention and reinvention, so aquatic animals deploy an array of strategies just to stay alive.

Air date: 2016-04-22

Runtime: 22 min

There are many reasons why insects survive, from strong, flexible shells to wings that give them the option of flying away from danger.

Air date: 2016-04-29

Runtime: 22 min

Nocturnal animals use the dark to escape predators, avoid the heat of the day, and take turns sharing food and resources.