See how scientists are racing to reveal Vietnam's biological riches before many species and their habitats disappear from the country's landscape due to expanding development and human activity.

The takhi is the only true wild horse left in the world. The so-called "wild" horses that abound in Australia and North America are actually feral. Find out what it means when a domestic animal becomes feral. 

Takhi horses became extinct in the wild in the late 1960s — but since 1997 they have been successfully breeding in the wild. Learn about the efforts behind this successful reintroduction. 

Take a look at Mongolia's takhi and discover how an Asian empire was won on horseback — and how Mongolia came to be known as the land of the horse. 

By unearthing sediment deposits tsunamis leave behind, scientists can study the waves' origins, extent, and frequency — and identify locations that have the geological apparatus to produce a tsunami, but haven't in written history.

Modern horses are part of the family Equidae. The fossil history of Equidae is well documented, but new evidence about its evolutionary history — and new interpretations of it — continue to accumulate. 

A tsunami hasn't affected the Pacific Northwest coast since 1964, yet bright-blue metal signs warning of them dot coastal streets. Find out why scientists are certain these communities are at risk.

Why did Hawaiian officials evacuate Hilo Bay in 1986 after a 7.7 earthquake but call off an evacuation in 2003 after a 7.8 one? The answer is DART. Learn more.

In 1991, the larvae of a striped, thumbnail-sized European shellfish floated quietly into the Hudson River. Find out how the zebra mussel invasion has been both tenacious and transformative. 

Unlike most zoo-raised or domestic species, Asian elephants have never been selectively bred, so they remain genetically wild. See how this helps with forest reintroduction efforts.