This is

This is Scientific American's 60 Second Science.

I'm Christopher Intagiata.

The tropics are well known for their biodiversity,

but another hotspot is mountains,

like the Hengduan Mountains in South Central China.

I mean it will look very much like this kind of familiar temperate alpine system,

but the plant diversity there is off the charts.

Rick Reh is associate curator of Botany at the Field Museum in Chicago.

These mountains harbor a third of all China's plant species.

And one hypothesis for mountain biodiversity

is that mountain uplift creates new climates and habitats.

You'll see coniferous forests and limestone and granite outcrops with glaciers and glacier-fed rivers and

alpine meadows.

Plants take advantage of the new niches and diversify.

Now Ria and his colleague,

Yawu Shing, have evidence supporting this idea

for a connection between mountain building

and biodiversity. They used DNA data

to build an evolutionary tree of plants in the Hengduan. Then they calibrated that tree with

fossil data and they saw an explosion and diversification around 8 million years

ago, right when uplift occurred. The results are in the proceedings of the National Academy of Sciences.

...