A look at the areas of the equator where the sun is challenged by snow and ice, meaning the animals and plants below must adapt or die.

The sun is a protector, a nourisher and a giver of life to all the planet's creatures. But as this episode shows, it can also be a tyrant - no more so than at the equator.

The time of year when Africa's savannah bakes under the equatorial sun - which requires a drastic change for the equator's usually seasonless conditions.

The daily battle faced by the wildlife of the high Andes of Ecuador, where every day is like summer and every night is like winter.

The Indonesian archipelago has thousands of islands, atolls and the largest concentration of coral reefs in the world. How was it created?

The rainforests of South East Asia are a battleground, where the globe's greatest diversity of species fight for light, food and life.

See how the towering rainforests of the Amazon rely on the equatorial sun and rains - fuelling an environment that is like nowhere else.

The Equator is not only the line that divides the Earth, it is also the evolutionary powerhouse of the world. See its effect on the Galapagos.