The far reaches of Antarctica are no longer visited only by scientists and their support staff. Adventure tourists and curiosity seekers from Europe, North America and beyond now come by the boatful — and they're bringing some souvenirs from home. Ecologist Steven Chown tells Robert Siegel that visitors unknowingly carry seeds on their clothes and bags. He says they've helped spread dozens of invasive plant species on the continent and risk permanently changing Antarctica's ecology.

Pigweed is a weed that's changed life for practically every cotton farmer in Georgia. One expert says if you can't manage it, you won't be picking your cotton field.

Do you buy that $100 Malbec, or will the $15 bottle fit the bill just as nicely? New research suggests your biology may help determine whether you can really taste a difference.

The Queen Elizabeth Prize for Engineering is a new award created with hopes to breathe new life into the field. One million British pounds will be awarded every two years for an engineering achievement deemed to have great benefit to humanity. Nominations for the prize opened last week. Robert Siegel talks to Lord Browne of Madingley, the former president of the Royal Academy of Engineering and the force behind the award.

Can sushi be sustainable? Yes, says one Oregon restaurant. It's selling that message in a popular new video. But most sushi purveyors aren't on the sustainability bandwagon.

The human brain craves predictability, according to neuroscientists, and when politicians appear to flip-flop, our brains don't like it. Often, we feel betrayed. NPR science correspondents Jon Hamilton, Alix Spiegel and Shankar Vedantam talk about why we're hard-wired to appreciate consistency.

Every habit-forming activity follows the same behavioral and neurological patterns, says New York Times business writer Charles Duhigg. His new book The Power of Habit explores the science behind why we do what we do — and how companies are working to use our habits to market products to us.

The Smithsonian Institution is working with NASA to plan a four-day festival next month to welcome space shuttle Discovery to its collection.