Plant Molecular Systematics Phylogenetics.ppt

Plant Molecular Systematics Phylogenetics

1. Plant Molecular Systematics
(Phylogenetics)

2. •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.

6. 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.

7. 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.

9. Plant Molecular Systematics
(Phylogenetics)
BY: Mary Beth Craig

10. 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

11. Pictures of DNA & RNA

12. Examples of Phylogenetic
Trees

13. Plants from Genus Phlox