The human eye is an amazing mechanism, able to detect anywhere from a few photons to a few quadrillion, or switch focus from the screen in front of you to the distant horizon in a third of a second. How did these complex structures evolve? Joshua Harvey details the 500 million year story of the human eye.
Explore the wild blue Caribbean waters of Cozumel, a lush paradise packed with marine surprises. From the spectacular Paso Del Cedral coral reef to the world's longest subterranean underwater cave system, go where only the bravest divers dare venture.
In the northeast corner of Botswana, the rainy season is months away. The sausage tree offers a beguiling oasis for wildlife--from birds and insects, to much larger mammals like elephants--all reeling from the dry conditions. Then, as the rains descend, brilliant red flowers bloom and entice parrots, squirrels, and sunbirds to help with pollination. Summer allows the sausage tree to live up to its name, delivering massive, sausage-shaped fruit, a nutritious feast and a cornerstone of life in this exotic ecosystem.
There are 200 million insects for each of us. They are the most successful animal group ever. Their key is an armoured covering that takes on almost any shape. Darwin's stag beetle fights in the tree tops with huge curved jaws. The camera flies with millions of monarch butterflies which migrate 2000 miles, navigating by the sun. Super slow motion shows a bombardier beetle firing boiling liquid at enemies through a rotating nozzle. A honey bee army stings a raiding bear into submission. Grass cutter ants march like a Roman army, harvesting grass they cannot actually eat. They cultivate a fungus that breaks the grass down for them. Their giant colony is the closest thing in nature to the complexity of a human city.