Manazza Phylogenetic

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Molecular

Molecular Phylogenetics
Molecular
Basis of Molecular Phylogenies
Overview
Phylogenetics Definitions
Phylogenetics
Genetic Variation and Evolution
Genetic
Source of Information for Phyogenetic Analyses
Source
Molecules As Documents of Evolutionary History
Molecules
Morphology vs. Molecules
Morphology
Molecular Tools
Molecular
Molecular Data
Molecular
Which Gene to Use?
Which
Applications of Molecular Phylogenetics
Applications

Molecular Phylogenetics
Molecular
Basis of Phylogenetics
Phylogenetics Definitions
field of biology which does deal with identifying and
field
identifying
understanding the evolutionary relationships among the
many different kinds of life on earth, both
living (extant)
living
dead (extinct)
dead
procedures
for
constructing
procedures
evolutionary trees
a phylogeny describe the
phylogeny
historical relationships among
lineages or organisms or their
parts (genes)
using trees to test hypotheses
using

Molecular Phylogenetics
Molecular
Basis of Phylogenetics
The Evolution of Species or Genes
Modeled as a Bifurcating Process

Can

be

two populations become reproductively isolated and
two
diverge due to random mutational processes
over time, this process may repeat itself, so that at any time, over
each population can be said to be most closely-related
each
to some other population with which it shares a direct
common ancestor
If genomes evolve the by accumulation of mutations
the amount of nucleotide sequence difference between a
the amount
pair of genomes should indicate how recently those two
how
genomes shared a common ancestor

Molecular Phylogenetics
Molecular
Basis of Phylogenetics
Phylogenetic Divergence
consists of changes in characters, such as amino acids in a
consists
changes
protein, or nucleotides in DNA
the
the

longer two populations remain reproductively isolated,
more divergence will occur

Given the existence of homologous characters across a set of homologous
populations, it should be possible to work backwards in time, work
ascending the tree, until a common ancestor of all populations common
in the set is reached

Molecular Phylogenetics
Basis of Phylogenetics
Genetic Variation Exists and Evolution Depends on It
How does genetic variation occur?
How
every organism posses a genome that contains all the
every
genome
biological information needed to construct and maintain a living example of that organism
The biological information contained in a genome is encoded in The
the nucleotide sequence of its DNA or RNA molecules and is
divided into discrete units (genes)
The information stored in a gene is
The
read by proteins, which attach to
the genome and initiate a series of
reactions (gene expression)

Molecular Phylogenetics
Basis of Phylogenetics
Genetic Variation Exists and Evolution Depends on It
How does genetic variation occur?
DNA segments (large or small) can be
DNA
altered
altered
duplicated
duplicated
deleted
deleted

Point mutations or other small changes (ex. A
new version of a gene (i.e. a new allele)
new

G) generate a

New loci are generated by gene duplication events
duplication

Molecular Phylogenetics
Basis of Phylogenetics
Genetic Variation Exists and Evolution Depends on It
How does genetic variation occur?
DNA replication
DNA
every time a cell divides, it must make a complete copy of its every
genome
must be extremely accurate in order to avoid introducing
must
mutations, or changes in the nucleotide sequence of a short
mutations
region of the genome
Inevitably, some mutations occur
errors in DNA replication
errors
effects of chemical agents
effects
or radiation

Molecular Phylogenetics
Molecular
Basis of Phylogenetics
Genetic Variation Exists and Evolution Depends on It
How does genetic variation occur?
Silent mutations
result in a change that has no effect on the functioning of the...
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