In this lesson students working in teams classify furniture, share their categories and rationales, then note how their different schemes vary arbitrarily. They then see how living organisms are classified, and note how these groupings are natural, nearly always reflecting the same ancestral relationships in nested hierarchies, regardless of the deeper criteria. Such patterns are revealed with a look ... Full description.

In this lesson, students will learn that some evolutionary change is rapid and discontinuous, and some change is gradual; how fossil evidence can provide clues to the past; and how speciation may account for evolutionary branching and diversification. Fossil shells of a land snail are arranged by layers of age into a sequence pattern suggesting gradual change, or punctuated equilibria. Students will ... Full description.

This site introduces a group of dinosaurs called ornithischians. There were many kinds of ornithischian dinosaurs dating back to the early Jurassic. The Ornithopoda included the hadrosaurs (duck-billed dinosaurs), the iguanodontids, the heterodontosaurs, the hypsilophodontids, and various others. The Ceratopsia included the horned dinosaurs, while the Ankylosauria and Stegosauria (now usually grouped ... Full description.

This information will provide students with an opportunity to understand the ideas proposed by Jean Baptiste de Lamarck in 1809. Lamarck was an eighteenth century naturalist who came to the idea that organisms change over time. Among other things, he proposed a mechanism for cumulative change that was dependent on the needs of organisms and resulted from the use or disuse of particular body parts. ... Full description.

In this activity, students will dissect a fish purchased from a fish market to study its external and internal anatomy. They will observe its gills, kidney, and blood through a microscope and take a variety of measurements of many of the internal organs. They will practice their observation skills by making accurate illustrations. These data and drawings will then be compared with some Antarctic fishes ... Full description.

In this activity, students will construct a set of sieves (four sizes) and use them to sort a soil sample. The activity will demonstrate that accuracy does not always have to involve expensive, high technology equipment. The sieves can be kept for use in later activities. A materials list and illustrated instructions are provided. Materials used to construct the sieves must be purchased. Full description.

Paleontologists occasionally find ancient tracks and footprints preserved in the rocks. This lesson opens the door to analysing those footprints, and gleaning information about body size and activities of the extinct animals that made the tracks. Students will learn that patterns can reveal much about the past, in light of the present; and that bipedalism has appeared several times. Relationships ... Full description.

This lesson introduces students to the building of cladograms as evolutionary trees showing how "shared derived characters" can be used to reveal degrees of relationship. Given some groups of organisms and some of their distinguishing characteristics, the students will construct a cladogram. Given a cladogram, the students will properly interpret and analyze that cladogram in terms of recognizing ... Full description.

In this lesson students learn how classification of organisms is based on evolutionary relationships. They will also learn how primates are categorized, and how they are related. Students transfer examples (names) of primates from their location in an outline hierarchy of primate groups into a set of nested boxes reflecting that same hierarchy. A cladogram can then be drawn illustrating how these ... Full description.

The Ceratosauria represent the earliest theropod dinosaurs and indeed may include the ancestor to all later theropods. This site discusses the overall morphology and then goes into more detail for three examples: Ceratosaurus nasicornis, Dilophosaurus wetherilli, and Segisaurus halli. Full description.