Phylogenetic terms and concepts

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• Phylogenetic terms and concepts
• Phylogeny
• 1. Defined
• 2. Phylogeny vs. tokogeny
• 3. Clade and monophyletic group
• 4. Sister group

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• Phylogenetic terms and concepts
• Phylogeny
• 1. Defined
• 2. Phylogeny vs. tokogeny
• 3. Clade and monophyletic group
• 4. Sister group

Willi Hennig (German 1913-1976)
Grundzüge einer Theorie der Phylogenetischen
Systematik (Hennig, 1950).
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• Phylogenetic terms and concepts
• B. Cladogram
• 1. Defined
• 2. Styles
• 2. Branches and nodes internal vs. external
  branches

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• Phylogenetic terms and concepts
• C. Characters and homology
• 1. Cladogram as a framework for studying the
  origin of variation among species.
• 2. Characters and character states
• 3. Apomorphies vs. plesiomorphies
• Autapomorphy vs. synapomorphy
• Synapomorphy vs. symplesiomorphy
• Hashmarks
• 4. Homology, analogy, and homoplasy

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• Phylogenetic terms and concepts
• C. Characters and homology
• 1. Cladogram as a framework for studying the
  origin of variation among species.
• 2. Characters and character states
• 3. Apomorphies vs. plesiomorphies
• Autapomorphy vs. synapomorphy
• Synapomorphy vs. symplesiomorphy
• Hashmarks
• 4. Homology, analogy, and homoplasy

e.g., useful characters for tetrapod
phylogenetics Skeletal Limbs (legs) zero,
four Fur no, yes Tail yes, no Bipedality no,
yes
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• Phylogenetic terms and concepts
• C. Characters and homology
• 1. Cladogram as a framework for studying the
  origin of variation among species.
• 2. Characters and character states
• 3. Apomorphies vs. plesiomorphies
• Autapomorphy vs. synapomorphy
• Synapomorphy vs. symplesiomorphy
• Hashmarks
• 4. Homology, analogy, and homoplasy

e.g., useful characters for tetrapod
phylogenetics Skeletal Limbs (legs) zero,
four Fur no, yes Tail yes, no Bipedality no,
yes Outgroup fish (also some invertebrate) Ingr
oup (amphibians, reptiles, monkeys, non-human
apes, humans)
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• Phylogenetic terms and concepts
• C. Characters and homology
• 1. Cladogram as a framework for studying the
  origin of variation among species.
• 2. Characters and character states
• 3. Apomorphies vs. plesiomorphies
• Autapomorphy vs. synapomorphy
• Synapomorphy vs. symplesiomorphy
• Hashmarks
• 4. Homology, analogy, and homoplasy

Birds
Bats
Insects
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• Phylogenetic terms and concepts
• C. Characters and homology
• 1. Cladogram as a framework for studying the
  origin of variation among species.
• 2. Characters and character states
• 3. Apomorphies vs. plesiomorphies
• Autapomorphy vs. synapomorphy
• Synapomorphy vs. symplesiomorphy
• Hashmarks
• 4. Homology, analogy, and homoplasy

Modern cetaceans vesitigial pelvis ,
occassionally hind limbs
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• Phylogenetic terms and concepts
• C. Characters and homology
• 1. Cladogram as a framework for studying the
  origin of variation among species.
• 2. Characters and character states
• 3. Apomorphies vs. plesiomorphies
• Autapomorphy vs. synapomorphy
• Synapomorphy vs. symplesiomorphy
• Hashmarks
• 4. Homology, analogy, and homoplasy

basilosaurids and dorudontids (ca. 40-30 Ma)
Basilosaurus had 2 tiny legs, probably used as
claspers when mating.
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II. Cladistics A. The taxon-by-character
matrix
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• II. Cladistics
• Synapomorphies as evidence of recency of common
  ancestry
• 1. Ingroup vs. outgroup
• 2. Parsimony and Ockhams Razor
• 3. Parsimony the optimality criterion as a means
  of dealing with incongruence

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• Cladistics
• C. Minmizing steps is the practical
  application of parsimony

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Snail
Hagfish
Perch
Salamander
Lizard
Mouse
Chimp
Human
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Notochord hollow dorsal nerve chord
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Notochord hollow dorsal nerve chord
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vertebrae jaws
Notochord hollow dorsal nerve chord
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Lungs, 4-legs
vertebrae jaws
Notochord hollow dorsal nerve chord
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Claws or nails
Lungs, 4-legs
vertebrae jaws
Notochord hollow dorsal nerve chord
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Fur mammary glands
Claws or nails
Lungs, 4-legs
vertebrae jaws
Notochord hollow dorsal nerve chord
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Loss of tail
Fur mammary glands
Claws or nails
Lungs, 4-legs
vertebrae jaws
Notochord hollow dorsal nerve chord
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Fur mammary glands
Claws or nails
10 steps
Lungs, 4-legs
vertebrae jaws
Notochord hollow dorsal nerve chord
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How to evaluate an alternative cladogram?
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How to evaluate an alternative cladogram?
Notochord hollow dorsal nerve chord
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How to evaluate an alternative cladogram?
vertebrae jaws
vertebrae jaws
Notochord hollow dorsal nerve chord
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How to evaluate an alternative cladogram?
Lungs, 4-legs
vertebrae jaws
vertebrae jaws
Notochord hollow dorsal nerve chord
27
How to evaluate an alternative cladogram?
Lungs, 4-legs
vertebrae jaws
vertebrae jaws
Notochord hollow dorsal nerve chord
28
How to evaluate an alternative cladogram?
Lungs, 4-legs
vertebrae jaws
vertebrae jaws
Notochord hollow dorsal nerve chord
29
How to evaluate an alternative cladogram?
Lungs, 4-legs
vertebrae jaws
vertebrae jaws
Notochord hollow dorsal nerve chord
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How to evaluate an alternative cladogram?
17 steps
Lungs, 4-legs
vertebrae jaws
vertebrae jaws
Notochord hollow dorsal nerve chord
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• Cladistics
• C. Minmizing steps is the practical
  application of parsimony

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• III. Sources of variation for characters
• Morphological and anatomical variation

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III. Sources of variation for characters B.
Genetic (e.g., DNA sequence) variation 1.
Source of genetic data 2. Alignment of DNA
sequences.
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III. Sources of variation for characters B.
Genetic (e.g., DNA sequence) variation 1.
Source of genetic data 2. Alignment of DNA
sequences.
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III. Sources of variation for characters B.
Genetic (e.g., DNA sequence) variation 1.
Source of genetic data. 2. Alignment of DNA
sequences.
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• Phylogenetic terms and concepts
• Phylogeny
• 1. Defined
• 2. Phylogeny vs. tokogeny
• 3. Clade and monophyletic group
• 4. Sister group