CoursesCourse 8
The journey of life
From a fish the length of a paper clip to people: about 520 million years in nine turning points. This course follows the backbone, the jaw, the leg, the egg, the wing, and the feather through the fossils, and asks whether humans were ever the goal.
Start lesson 1Lessons
- 1 A backbone and a bitePress the back of your neck: that row of bumps first appeared in a fish shorter than your thumb. How fossils are read, and how the first backbone and the first jaws changed the sea.
- 2 Out of the waterFins became fingers, eggs got a waterproof shell, and then some of the first land animals changed their minds and went back to the sea.
- 3 Fur, wings, and feathersMammals lived in the shadow of the dinosaurs, three different animals learned to fly, and feathers turn out to have been invented for something other than flight.
- 4 The newest branchA skull in a desert in Chad, a family of humans that once shared the earth, and the question the whole story raises: was it all leading to us, and is evolution over?
You’ll be able to
- Name the nine turning points in the story of the vertebrates, in order, and say roughly when each happened.
- Explain how paleontologists read fossils: how they form, how they are compared with living animals, and why “the earliest” keeps changing.
- Describe how fins became limbs, how the amniotic egg freed animals from water, and why some of them went back to the sea.
- Explain why birds are dinosaurs, why humans are one twig on a bushy tree, and why evolution is not a ladder toward us.
About this course
This course covers 征程：从鱼到人的生命之旅 (The Journey of Life: From Fish to Humans), the story of how the vertebrates, the animals with backbones, came to include us. It continues from Course 7, We are stardust, which followed the telescope outward and ended with the search for other earths. This course comes back to the one planet we know has life, and reads its history from the rock.
The argument and the examples come from the Chinese lecture series that this course adapts. Around them we add background for readers outside China, the findings that have come in since the lectures were given (the oldest jawed fish, the first dinosaurs with bat-like wings, the Denisovan skull from Harbin), the views of other scientists where they differ, and hands-on activities. Where the lecture’s numbers have changed we use the current ones, and we say which ideas are settled and which are still open.