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Welcome to Science Talk, the weekly podcast of Scientific American posted on June 17, 2009. I'm Steve Mercky. This week we'll go for a hike in Panama. Plus, we'll test your knowledge about some

recent science in the news. Back in March, I and a few other speakers on our latest scientific

American cruise got to take a walking tour of the Smithsonian Tropical Research Institute,

which is on Barrow, Colorado Island, in the middle of the 85-square-mile Gatun Lake,

which was created when they built the Panama Canal. You'll mostly hear me talking to Beth King, the Institute's science interpreter.

You'll also hear the voice of staff scientist Haralos Lesios, and some questions from a few

of the other folks on the tour.

If we sound out of breath at any point, it's because I edited out the portions where we just

finished climbing

many hundreds of steps and then later steep trails. So here we go on a tour of the Smithsonian

Tropical Research Institute or STRI or Stride with Beth King. So I think our plan is just to head

into the forest and we're going to go on one of the main research highways that goes through this outdoor laboratory and ends up at the area that's this permanent study site.

When you say highway, what do you actually mean?

I say that because there's this trail system all around the island, but there's some trails that are used much more

by others because they're going out to work and coming back.

All right, so we're entering the highway, and it's about three feet across.

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