Guide Note:
Systematics is the study of how all living things became so diverse and how all the groups of organisms both extinct and extant have diverged through time and geographical distribution from a distant common ancestor. A Phylogenetic Tree illustrates how groups are related by the order of the branches and how much change has occurred by the length of the branch. Phylogenies can be used to study different traits or the biogeography of a group of organisms.
Fast Facts:
- Discipline in Biology
- Important in understanding Evolution
- Uses Taxonomy as basis
- Ernst W. Mayr wrote Systematics and the Origin of Species in which he redefined a species as a distinct group of interbreeding individuals.
- Willi Hennig is considered the founder of phylogentic sytematics and first used Cladistics as a way to classify organisms based on evolutionary change.
- This method is superceding Phenetics which classified organisms on similarity of appearance based on the system of Carl Linnaeus
- Carl Woese examined genetic differences rather than comparing morphological similarities and so defined a new domain of living things called the Archaea which were neither bacteria nor eukaryotes.
