Lecture 1 – September 14, 2010
Email: firstname.lastname@example.org T@2-3PM LM205
Tamara Kelly email@example.com by appointment only
Midterm Exam is 75 minutes, 40 MC Balances of material i.e. equal number of questions.
Midterm includes material up to and including Oct. 21st (Mollusca II)
Final is 80MC, 20 from Midterm 1 material and 60MC of post-midterm material
Lecture 2 – September 16, 2010: Classification and Phylogeny (Ch4, 72-88)
Classification and Relationships
Aristotle had an interest in classifying and was the first person to start it
Linnaeus really developed the system to our current model (1700’s)
oBased on morphology – what the animal’s body shape looks like
oHierarchical taxonomic framework: at the top an all encompassing group i.e. Kingdoms,
Phylum, Class, Order, Family, Genus and Species aka “7 mandatory ranks”
oFor larger animal groups you have way more ranks; upto 30 ranks!
oBinomial nomenclature ex. Anguilla japonica (capital first letter for genus and species is the
second work aka species epithet
Phylogeny: Phylon means race and genesis means descent. Basically the history of development of species or
other group. Aka ancestry.
Characters: organismal features used to make evolutionary tree/phylogeny
Homology: character similarity resulting from common ancestry, shared character is because they
have one common ancestor which was held onto while the species evolved
Homoplasy: non-homologous characters which misrepresent common ancestry. Ex. Mammals, birds
and fish are NOT closely related but they all have similar body shapes. Evolutionary convergence of
fusiform shape (body is tapered on both ends) due the environment they live in.
How do we use character variation to reconstruct phylogeny? Cladistics
Cladistics: evaluation of information for tree building and classification.
Cladogram: End result or diagram based on the cladistic analysis, your evolutionary tree. Common
ancestor is at the base of the diagram and species branch off. Can get huge! Clade is group of
organisms that includes most recent common ancestor and all members and descendants of that
Polarity: Basically looks at different forms of a character. Ex some animals have an opposable thumb
while other don’t. Did the common ancestor have the opposable thumb or not? Cladistics is unbiased
because it allows you to ask questions about its ancestry.
oOutgroup comparison: Examines polarity of a character state. Ex. Outgroup is at the bottom
of the clade and you examine say vertebral colomn. The second outgroup may have the vertebral
colomn. Outgroup is basically the closest ancestor that lacks the characteristic you’re
Sources of Phylogenetic info
Comparative morphology: includes the study of the developmetal origin aka embryo. Eg. Skull
bones, limb bones, scales, hairs. Where can you get this information? Fossil records and living species!
Fossil day plays an important role even today.
Comparative biochemistry: gene and protein sequencing sg. mtDNA (mito DNA changes fast), tRNA
(changes slow). This is done mostly from living material but can also done from fossil material.
Comparative cytology: examines chromosomes, number of it, shape and associated material (ex.
Histones). Only from living material.