Lesson Summary: Evolutionary trees and patterns in the history of life

Lesson summary for... Evolutionary trees and patterns in the history of life Author/Source: UC Museum of Paleontology

Overview:	Scientists use many different lines of evidence to reconstruct the evolutionary trees that show how species are related. This article is located within Evolution 101.
Concepts:	This lesson covers the following concepts: Biological evolution accounts for diversity over long periods of time. Through billions of years of evolution, life forms have continued to diversify in a branching pattern, from single-celled ancestors to the diversity of life on Earth today. Present-day species evolved from earlier species; the relatedness of organisms is the result of common ancestry. Anatomical similarities of living things reflect common ancestry. Evolution does not consist of progress in a particular direction. Scientists use anatomical evidence to infer the relatedness of taxa. Classification is based on evolutionary relationships. Evolutionary trees (e.g., phylogenies or cladograms) are built from multiple lines of evidence.
Grade Level:	9-12
Time:	30-40 minutes
Teacher Background:	Explore these links for additional information on the topics covered in this lesson: Classification/Phylogenetics
Teaching Tips:	This article provides a comprehensive, general introduction to phylogenetics. It would make a good opening reading for an activity in which students apply phylogenetic concepts to specific data sets, research the relationships within a particular clade, or investigate the tree of life.