How can we establish evolutionary relationships between organisms?
Systematics & Phylogeny
Darwin envisioned that all species originated from a single common ancestor
Homologous Characters
Similarity may not = evolutionary relationships
Homoplasy
Anagenesis
o Anagenesis - Gradual phyletic change in a lineage as the environment shifts over time
o Anagenesis does not increase biodiversity - it is simply the gradual transformation of one "species" into another
o Anagenesis is often illustrated by a straight lin
Morphies
Cladistics relies on analysis of only shared derived characters
Cladograms depict evolutionary relationships
Phylogenetic Trees
Other Phylogenetic Methods
Estimating when species diverged from a common ancestor
Statistical Approaches
o The maximum likelihood method
o compares alternative trees with specific models to find the tree that is most likely to have produced the observed distribution of molecular character states
o The genetic distance method
o calculates the overall proporti
Using Genetic Distances to Construct a Phylogenetic Tree
Bird as an example of Monophyletic group
Example of Polyphyletic Group
Paraphyletic Group
Distinguishing Between Ancestral and Derived Characters
Examples of ancestral versus derived characters
principle of parsimony
o The principle of parsimony states that the simplest plausible explanation (fewest assumptions) of any phenomenon is the best
o The "best" cladogram is the one that hypothesizes the smallest number of evolutionary changes
Out vs In Group
Using Cladistics to Construct a Phylogenetic Tree
The Cladistic Revolution
Choosing An Optimal Cladogram via Parsimony
Two alternative phylogenic tree for the six clades
Analysis of shared characters
Molecular Clocks
Molecular Sequences
The biological basis of evolution
molecular characters
molecular characters
molecular characters
molecular characters
horizontal gene transfer
horizontal gene transfer
Comparative Biology
The Comparative Method
Origins of Infectious Diseases
HIV
Origins of HIV
TP 1
TP 2
TP 3
TP 4
TP 5
TP 6
How can we establish evolutionary relationships between organisms?
Systematics & Phylogeny
Darwin envisioned that all species originated from a single common ancestor
Homologous Characters
Similarity may not = evolutionary relationships
Homoplasy
Anagenesis
o Anagenesis - Gradual phyletic change in a lineage as the environment shifts over time
o Anagenesis does not increase biodiversity - it is simply the gradual transformation of one "species" into another
o Anagenesis is often illustrated by a straight lin
Morphies
Cladistics relies on analysis of only shared derived characters
Cladograms depict evolutionary relationships
Phylogenetic Trees
Other Phylogenetic Methods
Estimating when species diverged from a common ancestor
Statistical Approaches
o The maximum likelihood method
o compares alternative trees with specific models to find the tree that is most likely to have produced the observed distribution of molecular character states
o The genetic distance method
o calculates the overall proporti
Using Genetic Distances to Construct a Phylogenetic Tree
Bird as an example of Monophyletic group
Example of Polyphyletic Group
Paraphyletic Group
Distinguishing Between Ancestral and Derived Characters
Examples of ancestral versus derived characters
principle of parsimony
o The principle of parsimony states that the simplest plausible explanation (fewest assumptions) of any phenomenon is the best
o The "best" cladogram is the one that hypothesizes the smallest number of evolutionary changes
Out vs In Group
Using Cladistics to Construct a Phylogenetic Tree
The Cladistic Revolution
Choosing An Optimal Cladogram via Parsimony
Two alternative phylogenic tree for the six clades
Analysis of shared characters
Molecular Clocks
Molecular Sequences
The biological basis of evolution
molecular characters
molecular characters
molecular characters
molecular characters
horizontal gene transfer
horizontal gene transfer
Comparative Biology
The Comparative Method
Origins of Infectious Diseases
HIV
Origins of HIV
TP 1
TP 2
TP 3
TP 4
TP 5
TP 6