CHAPTER 25 TRACING PHYLOGENY

I. PHYLOGENY AND SYSTEMATICS A.TAXONOMY EMPLOYS A HIERARCHICAL SYSTEM OF CLASSIFICATION  SYSTEMATICS, THE STUDY OF BIOLOGICAL DIVESRISTY AN EVOLUTIONARY CONTEXT, INCLUDES TAXONOMY, THE IDENTIFICATION AND CLASSIFICATION OF SPECIES.

B. TAXONOMY  TAXA: CLASSIFICATION SYSTEM FOR ORGANISMS KINGDOM PHYLA CLASS ORDES FAMILY GENUS SPECIES

C. THE BRANCHING PATTERN OF A PHYLOGENETIC TREE REPRESENTS THE TAXONOMIC HIERARCHY  PHYLOGENETIC TREES REPRESENT HYPOTHESES DEVELOPED BY SYSTEMATISTS WHOSE GOAL IS TO HAVE CLASSIFICATION REFLECT EVOLUTIONARY HISTORY.

D. DETERMINING MONOPHYLETIC TAXA IS A KEY TO CLASSIFYING ORGANISMS ACCORDING TO THEIR EVOLUTIONARY HISTORY  A TAXON IS MONOPHYYLETIC IF A SINGLE ANCESTOR GAVE RISE TO ALL SPECIES IN THAT TAXON AND TO NO SPECIES PLACED IN ANY OTHER TAXON.  PHYLOGENETIC HYPOTHESES ARE BASED ON HOMOLOGIES (SIMILARITIES DUE TO COMMON ANCESTRY)

E. MOLECULAR BIOLOGY PROVIDES POWERFUL NEW TOOLS FOR SYSTEMATICS  EVOLUTIONARY RELATIONSHIPS CAN BE REVEALED BY COMPARING AMINO ACID SEQUENCES OF PROTEINS AND NUCLEOTIDE SEQUENCES OF DNA AND RNA