It’s the dream of kids all around the world to see giant beasts walk the Earth again. Could -- and should -- that dream be realized? Hendrik Poinar talks about the next big thing: the quest to engineer a creature that looks very much like our furry friend, the woolly mammoth. The first step, to sequence the woolly genome, is nearly complete. And it’s huge.

Deep brain stimulation is becoming very precise. This technique allows surgeons to place electrodes in almost any area of the brain, and turn them up or down -- like a radio dial or thermostat -- to correct dysfunction. Andres Lozano offers a dramatic look at emerging techniques, in which a woman with Parkinson's instantly stops shaking and brain areas eroded by Alzheimer's are brought back to life.

In 1812, four men at Cambridge University met for breakfast. What began as an impassioned meal grew into a new scientific revolution, in which these men -- who called themselves “natural philosophers” until they later coined “scientist” -- introduced four major principles into scientific inquiry. Historian and philosopher Laura Snyder tells their intriguing story.

When two people are trying to make a deal -- whether they’re competing or cooperating -- what’s really going on inside their brains? Behavioral economist Colin Camerer shows research that reveals how badly we predict what others are thinking. Bonus: He presents an unexpected study that shows chimpanzees might just be better at it.

Throughout humankind's history, we've driven species after species extinct: the passenger pigeon, the Eastern cougar, the dodo ... But now, says Stewart Brand, we have the technology (and the biology) to bring back species that humanity wiped out. So -- should we? Which ones? He asks a big question whose answer is closer than you may think.

Modern psychiatric drugs treat the chemistry of the whole brain, but neurobiologist David Anderson has a more nuanced view of how the brain functions. He shares new research that could lead to targeted psychiatric medications -- that work better and avoid side effects. How's he doing it? For a start, by making a bunch of fruit flies angry.

Humankind has been looking for the giant squid (Architeuthis) since we first started taking pictures underwater. But the elusive deep-sea predator could never be caught on film. Oceanographer and inventor Edith Widder shares the key insight -- and the teamwork -- that helped to capture the squid on film for the first time.

(NOTE: Statements in this talk have been challenged by scientists working in this field. Please read "Criticisms & Updates" below for more details.) "Desertification is a fancy word for land that is turning to desert," begins Allan Savory in this quietly powerful talk. And it's happening to about two-thirds of the world's grasslands, accelerating climate change and causing traditional grazing societies to descend into social chaos. Savory has devoted his life to stopping it. He now believes -- and his work may show -- that a surprising factor can protect grasslands and even reclaim degraded land that was once desert.

An insect's ability to fly is one of the greatest feats of evolution. Michael Dickinson looks at how a fruit fly takes flight with such delicate wings, thanks to a clever flapping motion and flight muscles that are both powerful and nimble. But the secret ingredient: the incredible fly brain.

Human growth has strained the earth's resources, but as Johan Rockström reminds us, our advances also give us the science to recognize this and change behavior. His research has found nine "planetary boundaries" that can guide us in protecting our planet's many overlapping ecosystems.