Two pythons: evolution of snakes When did snakes evolve? Snakes evolved from lizards only about 150 million years ago, during the Jurassic Period. This is during the time of the dinosaurs, about the [...]
Chinese drawing of the human organs (about 1200) Eyes and fevers Between the Middle Ages and modern times, doctors have learned a lot of new things about how human bodies [...]
Ebers Papyrus, one of the oldest known medical texts about the human body. From Egypt, about 1550 BC How does the human body work? Doctors have been trying to figure [...]
History of cholera: Washing clothes in the river (India) Where did cholera get started? Cholera (KOLL-uh-rah) is a very serious sickness. It probably first got started in India. History of disease [...]
Who was Aristotle? An ancient Egyptian papyrus with a scrap of Aristotle's "Politics" Aristotle's family Aristotle's father was Nicomachus, a doctor who lived near Macedon, in the north of Greece. [...]
A turtle in the desert During the Triassic period (about 248 to 199 million years ago), most of Earth's land continued to stick together in one big supercontinent, Pangaea. Because [...]
Tertiary period: Large animals evolved like moose Dinosaurs become extinct The Tertiary period begins with the catastrophe that killed off the dinosaurs at the end of the Cretaceous Period, about 65 [...]
Silurian period: Trout swimming When was the Silurian period? The beginning of the Silurian period was about 443 million years ago. Some environmental problem at the end of the Ordovician [...]
Two and a half billion years ago, the Archaean Eon ended and the Proterozoic Eon began. Trillions of prokaryote cells lived in Earth's oceans. Some of these cells could photosynthesize their energy [...]
Kids eating food (thanks to USDA) - get ready to digest food! How do you digest food? When animals, including people like you, digest their food, they use an oxidation reaction to [...]
