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.
UC Museum of Paleontology
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.
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Biological evolution accounts for diversity over long periods of time. (LS4.A, LS4.D)
- 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. (LS4.A)
- Anatomical similarities of living things reflect common ancestry. (LS4.A)
- Evolution does not consist of progress in any particular direction.
- Scientists test their ideas using multiple lines of evidence. (P6, NOS2)
- Scientists can test ideas about events and processes long past, very distant, and not directly observable.
- Scientists use anatomical evidence to infer the relatedness of taxa. (LS4.A)
- Classification is based on evolutionary relationships.
- Evolutionary trees (i.e., phylogenies or cladograms) are built from multiple lines of evidence.
- Evolutionary trees (i.e., phylogenies or cladograms) portray hypotheses about evolutionary relationships.