Phylogenetic tree

Definition

A phylogenetic tree is a diagram that represents the evolutionary relationships among various biological species based on their genetic characteristics. It helps in understanding how different species, including deeply branching bacteria, are related through common ancestors.

5 Must Know Facts For Your Next Test

1. Phylogenetic trees are constructed using genetic data such as DNA or RNA sequences from different organisms.
2. Deeply branching bacteria occupy the base of the phylogenetic tree and are considered some of the oldest forms of life.
3. The structure of a phylogenetic tree includes nodes (representing common ancestors) and branches (indicating evolutionary paths).
4. Rooted trees have a single ancestral lineage whereas unrooted trees display relationships without showing an ancestral root.
5. Phylogenetic trees can be used to trace microbial evolution and understand prokaryotic diversity.

Review Questions

• What type of data is primarily used to construct phylogenetic trees?
• Why are deeply branching bacteria significant in the context of a phylogenetic tree?
• What is the difference between rooted and unrooted phylogenetic trees?

Related terms

Cladogram: A type of diagram that shows relationships among organisms but does not represent evolutionary time.

Molecular Clock: A method that uses mutation rates in DNA to estimate the time two species have been evolving independently.

Horizontal Gene Transfer: The movement of genetic material between unicellular and/or multicellular organisms other than via vertical transmission (from parent to offspring).