How did life begin on Earth? Curiously, scientists often search for the answer on other planets or moons in our solar system. After all, if we want to see whether our theories are right, we need to find another example of life somewhere. The search has taken us to some strange places seemingly frozen in time that give us hints to what Earth looked like billions of years ago when life first appeared in the geologic record: places like Mars that show evidence of fossil oceans, and places like Saturn’s moon, Enceladus, that show evidence of liquid water oceans containing organic molecules hidden under an icy crust. NASA astrobiologist Chris McKay has been a member of missions that sent spacecraft to these and other places in search of that elusive other example of life in the universe. He recently sat down with producer Miles Traer to discuss the best current theories for the origin of life on Earth, why Antarctica is a lot like one of Saturn’s moons, the challenges of collecting data from other planets, and the reasons we’re captivated by the question, “Are we alone in the universe?”

“In Asia or Africa around 60 million years ago, snakes became more venomous, though scientists aren’t quite sure why then and there.” Sometimes understanding global environmental change requires that we simply know how nature works. And not just the pleasant side of nature, but all of it. When we look back through the wonders of Darwinian evolution, we gain a deeper appreciation for certain aspects of the natural world that seem… uncomfortable: things like snakes, spiders, jellyfish, Komodo Dragons, and tiny caterpillars that can easily kill humans. This week, scientist Christie Wilcox takes us on a journey through the evolution of the chemical cocktails we call “venom,” which she wrote about in her new book called, “Venomous: How Earth’s Deadliest Creatures Mastered Biochemistry.” Travel along from venom’s earliest formation, its evolution into a potent weapon, and its further transformation by doctors today as a potentially revolutionary tool in developing new medicines.

Image by Brent Myers
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