Plant Molecular Systematics (Phylogenetics)

Systematics classifies species based on similarity of traits and possible mechanisms of evolution, a change in the gene pool of a population over time. Phylogenetic systematics is that field of biology that does deal with identifying and understanding the evolutionary relationships among the many different kinds of life on earth, both living and dead. Evolutionary theory states that similarity among individuals or species is attributable to common descent, or inheritance from a common ancestor. Evolution requires genetic variation which results from changes within a gene pool, the genetic make-up of a specific population.

Nodes, each represent a taxonomic unit (species, populations, individuals), Branches, define the relationship between the taxonomic units in terms of descent and ancestry. Branch length usually represents the number of changes that have occurred in the branch. Root, representing a common ancestor, from which a unique path leads to any other node. Unrooted tree only specifies the relationship among species, without identifying a common ancestor, or evolutionary path.

In this case, an outgroup could be a gene from another primate, such as baboon, which is known to have branched away from the four species above before the common ancestor of the species.

Plant Molecular Systematics (Phylogenetics) BY: Mary Beth Craig

Definitions Wikipedia.com defines Molecular Systematics “a product of the traditional field of systematics and the growing field of bioinformatics. It is the process of using data on the molecular constitution of biological organisms' DNA, RNA, or both, in order to resolve questions in systematics, i.e. about their correct scientific classification or taxonomy from the point of view of evolutionary biology. It is also known as computational systematics. It may also be referred to as molecular genetics or molecular evolution.” Phylogeny is the origin and evolution of a set of organisms, usually of a species. Wikipedia.com

Pictures of DNA & RNA

Examples of Phylogenetic Trees

Plants from Genus Phlox