tropical zone

"Whereas Antarctic krill live in a place that is essentially unpopulated," says Xing, "we chose rotifers in part because they occur throughout the world's temperate and tropical zones, where people live."

In the country’s tropical zones, where the weather is reliably balmy, the giant northern’s gluttonous garrisons are plentiful.

This growing taste for chocolate, which would become a beverage on par with tea or coffee, also led to its cultivation in European colonies in tropical zones throughout the world.

Research has shown that the Earth’s tropical zone—a warm belt around the middle of the planet—is swelling poleward, a phenomenon that some studies suggest is driven by atmospheric changes linked to climate change.

More recently, however, their history has been one of marginalisation and neglect in underdeveloped regions such as the Costa Chica, a dry, tropical zone to the south-east of Acapulco.