Juan Enriquez: We can reprogram life. How to do it wisely

For four billion years, what lived and died on Earth depended on two principles: natural selection and random mutation. Then humans came along and changed everything — hybridizing plants, breeding animals, altering the environment and even purposefully evolving ourselves. Juan Enriquez provides five guidelines for a future where this ability to program life rapidly accelerates. "This is the single most exciting adventure human beings have been on," Enriquez says. "This is the single greatest superpower humans have ever had."

Amy Cuddy: Your body language shapes who you are

Body language affects how others see us, but it may also change how we see ourselves. Social psychologist Amy Cuddy shows how “power posing” -- standing in a posture of confidence, even when we don’t feel confident -- can affect testosterone and cortisol levels in the brain, and might even have an impact on our chances for success.