“The dance between life and the planet has been going on for a long time,” entomologist Dr Samuel Ramsey explains in this Crash Course Biology video. And though Earth held the essential ingredients for life over 4.6 billion years ago, he explains, it lacked the atmosphere, oxygen, or vast oceans that we depend on today.
Then at some point, around 3.8 billion years ago, something helped life begin on Earth:
“There are a few different ideas about how this might have gone down. One is that life arose from the power of lightning, volcanoes, and radiation from space, brewing the oceans into a nutrient-rich soup of organic molecules. Another possibility is that those first organic molecules formed in deep-sea vents with the perfect temperature and chemical balance.”
“Others think that those first compounds might have even been brought by a meteorite. The point is: there’s more than one way life’s soup can brew.”
Explore the early tumultuous state of Earth, its transition to a suitable habitat for life over billions of years, the concept of macroevolution, the role of RNA and DNA, the timeline of life on Earth set to a 24-hour clock, the significance of stromatolites and fossils, the contributions of Dr. Meemann Chang to paleontology, and the drivers of macroevolution, such as plate tectonics, atmospheric changes, and mass extinctions.
Dr Sammy discusses our planet’s astonishing odyssey of life, from nonexistence to intricate, interwoven complexity, in this 16th episode from the series. He summarizes:
“Earth’s changing conditions have triggered game-changing leaps for life. Life, in turn, has shaped the Earth right back, even altering its atmosphere. We wouldn’t be the same without each other.
“And as much as we humans like to think that we’re the pièce de résistance when it comes to evolution, we’ve been around for less than a geological second. We’ve got a lot to learn from all the life that’s come before us.”
Watch this next: What is Life? Dr. Samuel Ramsey explains with Crash Course Biology.
Then watch these related videos next on TKSST:
• The mysterious origins of life on Earth
• Carl Sagan’s Cosmic Calendar
• Hidden volcanoes and superheated deep-sea vents on A Perfect Planet
• OSIRIS-REx returns to Earth with 250 pristine grams of Bennu asteroid
• What exactly happened on the day that dinosaurs died?
• Who was the first human?
• What have we found while looking for another Earth?