Evidence of Evolution

Learn about evolution evidence: fossils, anatomy, embryology!

Background When Charles Darwin first proposed the idea that all new species descend from an ancestor, he performed an exhaustive amount of research to provide as much evidence as possible. Today, the major pieces of evidence for this theory can be broken down into the fossil record, embryology, comparative anatomy, and molecular biology. Fossils This is a series of skulls and front leg fossils of organisms believed to be ancestors of the modern-day horse. Give two similarities between each of the skulls that might lead to the conclusion that these are all related species. What are two changes in skull anatomy that occurred from the dawn horse to the modern horse? What are the two biggest changes in leg anatomy that occurred from the dawn horse to the modern horse? For each animal, indicate what type of movement each limb is responsible for. Animal Primary Function Human Using tools, picking up and holding objects Whale Cat Bat Compare the skeletal structure of each limb to the human arm. Relate the differences you see in form to the differences in function. Animal Comparison to Human Arm in Form Comparison to Human Arm in Function Whale Whale has a much shorter and thicker humerus, radius, and ulna. Much longer metacarpals. Thumb has been shortened to a stub. The whale fin needs to be longer to help in movement through water. Thumbs are not necessary as the fins are not used for grasping. Cat Bat Compare the anatomy of the butterfly and bird wing below. What is the function of each of these structures? Compare the anatomy of the butterfly and bird wing below. How are they different in form? Give specific differences. You have now studied two different types of anatomical structures: Homologous structures show individual variations on a common anatomical theme. These are seen in organisms that are closely related.Give an example of a homologous structure from this activity: Analogous structures have very different anatomies but similar functions. These are seen in organisms that are not necessarily closely related, but live in similar environments and have similar adaptations.Give an example of an analogous structure from this activity: