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Phylogeny and Systematics. AP Biology 2012 Monkemeier. Phylogeny. The evolutionary history of a species or a group of species. In constructing phylogenies Fossil Records Systematics Morhphological resemblances Molecular systematics. Classification and Evolutionary History.
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Phylogeny and Systematics AP Biology 2012 Monkemeier
Phylogeny • The evolutionary history of a species or a group of species. • In constructing phylogenies • Fossil Records • Systematics • Morhphological resemblances • Molecular systematics
Classification and Evolutionary History • Taxonomy – an ordered division of organisms into categories based on a set of characteristics used to assess similarities and differences. • Binomial Nomenclature • Hierarchical classification: Domain, Kingdom, etc
Cladogram • A diagram that that shows patterns of shared characteristics between organisms. • If the shared characteristics between organisms are due to a common ancestry than the cladogram forms the basis of a phylogenetic tree. • Clade: (a branch) a group of species that includes an ancestral species and all its descendents.
Showing Relationships • Homologous Structures: Corresponding organs and other body parts that are alike in basic structure and origin. • Shared Derived Characters: specific modifications of homologous structures unique to a particular clade.
How to Build a Cladogram • How to Build a Cladogram
A valid Clade is monophyletic. Monophyletic: conisists of the ancestral species and all of its descendants. Cladograms -
A Grouping that consists of an ancestral species and some, but not all, of the descendants. Paraphyletic
Polyphyletic: a grouping of several species that lack a common ancestor. Polyphyletic
Taxon: biological unit: species, family, kingdom, etc. Branches: represent the pathway that traces the proposed evolutionary history of the lineages Nodes: represent hypothetical ancestors of the descendant clades (more technical language, clades being a group of taxa) of that node Dades: Pairs of Taxa Outgroup: the taxon used to act as a basis for the analysis that produced the tree Phylogenetic Trees: Depict hypotheses about evolutionary relationships.
Taxons A and B did not evolve more recently than Taxons E and F. The common ancestor of E, F preceded the last common ancestor of A and B The sequence of the branching does not indicate actual ages of the particular species. Interpreting a Phylogenetic Tree