This Click & Learn traces the flow of energy from the Sun all the way to cells within organisms. The embedded questions and calculations guide students’ understanding of how energy is distributed through a variety of ecosystems.
This model shows the skull of Tiktaalik, a vertebrate that existed about 375 million years ago and had features of both fish and tetrapods (four-limbed animals).
This model shows the skeleton of Tiktaalik, a vertebrate that existed about 375 million years ago and had features of both fish and tetrapods (four-limbed animals).
This model shows the pectoral fin bones of Tiktaalik, a vertebrate that existed about 375 million years ago and had features of both fish and tetrapods (four-limbed animals).
This model shows the pelvis of Tiktaalik, a vertebrate that existed about 375 million years ago and had features of both fish and tetrapods (four-limbed animals).
This model shows the humerus bone of Tiktaalik, a vertebrate that existed about 375 million years ago and had features of both fish and tetrapods (four-limbed animals).
This interactive module explores examples of how changes in one species can affect species at other trophic levels and ultimately the entire ecosystem.
A number of interactive questions are embedded within the short film The Biology of Skin Color, which explores the hypothesis that the variations in skin color in humans arose as adaptations to the intensity of ultraviolet radiation in different parts of the world.