A New History of Life [repost]

Life is stranger than fiction. Recent investigations hint at episodes in the history of life on Earth that rival the most imaginative movies. For example: Could our planet have been seeded with life from elsewhere? Did the development of life create conditions that threatened to poison the biosphere? How have natural forces conspired, over and over, to remove most traces of life from the planet? And how has life itself responded with determination to survive and thrive in a multitude of astonishing forms?

The story of our world and the different living things that have populated it is an amazing epic with millions of species both familiar and strange, exotic settings, planet-wide cataclysms, and surprising plot twists. Humans are only the latest characters in this long-running drama, which has always been utterly unpredictable, since periodic mass extinctions are inevitably followed by life rebounding in unexpected ways. Indeed, life and the planet have developed together, each driving the evolution of the other.

Equally intriguing are the details of how scientists know what they do about the past. It is a detective story as riveting as any forensic thriller, with paleontologists and geologists taking the most unassuming pieces of evidence—a bit of fossil bone, a sequence of layers in rock, a geochemical test—and reading a rich narrative of past events. And by drawing on tools from other disciplines, such as biology, meteorology, and astrophysics, the scenes they describe can be truly monumental in scope, encompassing the entire Earth and even phenomena beyond the planet.

This multidisciplinary effort to understand Earth as a whole, as a system composed of many interacting parts, is called Earth system science, and it has given us an unprecedented understanding of the planet and the unfolding panorama of life.

A New History of Life tells this all-embracing story of life on Earth—its origins, extinctions, and evolutions—in 36 lavishly illustrated lectures that assume no background in science. At half an hour per lecture, you cover the entire 4.54-billion-year history of Earth in 18 hours, averaging 70,000 years per second! Professor Stuart Sutherland of The University of British Columbia gives a gripping account, showing why he is an award-winning and nationally recognized teacher.

Cycles of Ruin and Renewal

Professor Sutherland notes that if the story of Earth is compared to the height of the Washington Monument, then all of human history is the thickness of a sheet of paper balanced at the top. He devotes most of A New History of Life to the incredible happenings beneath that piece of paper. The events before humans arrived on the scene include stirring episodes such as these:
Snowball Earth: More than half a billion years ago, Earth apparently plunged into a frozen state, with the world almost completely iced over. According to some theories, this snowball phase should have been permanent and life eventually extinguished. But something saved the planet.
Cambrian explosion: Before the start of the Cambrian period, life was mostly unicellular. Then complexity soared in an explosion of genetic diversification. The major new phyla and weird evolutionary dead-ends are recorded in the fossils of the renowned Burgess Shale in British Columbia.
Age of giant insects: During Earth’s coal-forming phase in the Carboniferous period, dragonflies had 30-inch wingspans and cockroaches reached 20 inches in length. What caused the big bugs? The storage of atmospheric carbon in what became coal deposits may have played a crucial role.
Cretaceous-Paleogene extinction: The dinosaurs and more than half of all other species were doomed after a six-mile-wide asteroid struck Earth 65.5 million years ago. The initial blast, shock wave, flying debris, fires, and tsunami were just the beginning, as the biosphere went into a cascade of failures.