CHAPTER 25: PHYLOGENY AND SYSTEMATICS
THE FOSSIL RECORD AND GEOLOGIC TIME
I.
SEDIMENTARY ROCKS ARE THE RICHEST SOURCE OF FOSSIL
A. How Fossils Form–
B. Limitations of the Fossil Record–
II.
PALEONTOLOGISTS USE A VARIETY OF METHODS TO DATE FOSSILS
A. Relative Dating–
Geological time scale–
B. Absolute Dating–
Radiometric dating– half-life–
III. THE FOSSIL RECORD IS A SUBSTANTIAL, BUT INCOMPLETE CHRONICLE OF EVOLUTIONARY HISTORY
IV. PHYLOGENY HAS A BIOGEOGRAPHICAL BASIS IN CONTINENTAL DRIFT–
V.
Pangaea–
THE HISTORY OF LIFE IS PUNCTUATED BY MASS EXTINCTIONS
A. Examples of Major Adaptive Radiations–
B. Examples of Mass Extinctions–
Impact hypothesis–
SYSTEMATICS: CONNECTING CLASSIFICATION TO PHYLOGENY
VI. TAXONOMY EMPLOYS A HIERARCHIAL SYSTEM OF CLASSIFICATION
A. The Binomial
1. Genus–
2. specific epithet–
B. Hierarchical Classification–
1. family–
orders–
classes–
phyla–
kingdom–
2. taxon–
3. phylogenetic trees–
VII. MODERN PHYLOGENNETIC SYSTEMATICS IS BASED ON CLADISTIC ANALYSIS
A. Clades: Monophyletic Groups
1. Cladogram–
2. Monophyletic–
B. Constructing a Cladogram
1. Sorting homology from analogy
a) homology–
b) analogy—
convergent evolution–
2. Identifying shared derived characters–
a) shared primitive character–
b) shared derived character–
3. Performing outgroup comparison–
outgroup–
ingroup–
C. Summary of Cladistic Analysis–
phylocode–
VIII. SYSTEMATICS CAN INFER PHYLOGENY FROM MOLECULAR DATA
A. Protein Comparison
B. Phylogenetic Data from DNA Sequences
1. DNA-DNA hybridization—
2. DNA sequencing—
C. Aligning the DNA Sequences–
IX. THE PRINCIPLE OF PARSIMONY HELPS SYSTEMATISTS RECONSTRUCT PHYLOGENY
Parsimony–
X.
HYLOGENETIC TREES ARE HYPOTHESES
XI. MOLECULAR CLOCKS MAY KEEP TRACK OF EVOLUTIONARY TIME
A. Using Molecular Clocks to Measure Absolute Time
B. Using a Molecular Clock to Date the Origin of HIV
XII. MODERN SYSTEMATICS IS FLOURISHING WITH LIVELY DEBATE
Phylogenetic fuse–