Cosmos #9

This episode explores the palaeogeography of Earth over millions of years, and its impact on the development of life on the planet.

The lignin-rich trees evolved in the Carboniferous era about 300 million years ago but were not edible by species at the time and would instead fall over and become carbon-rich coal.

50 million years later volcanic activity would burn the carbonaceous matter, releasing carbon dioxide and acidic components, creating a sudden greenhouse gas effect that warmed the oceans and released methane from the ocean beds, all leading towards the Permian–Triassic extinction event, killing 90% of the species on Earth.

Scientists like Abraham Ortelius hypothesized the idea that land masses may have been connected in the past.

Abraham Ortelius

 

Alfred Wegener hypothesized the idea of a super-continent Pangaea and continental drift despite the prevailing idea of flooded land-bridges at the time.

Alfred Wegener

 

Bruce C. Heezen and Marie Tharp discovered the Mid-Atlantic Ridge that supported the theory of plate tectonics.

Bruce C. Heezen & Marie Tharp

 

The show concludes by noting how Earth’s landmasses are expected to change in the future and postulates what may be the next great extinction event.

 

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