Why
Classification
classify?
Systematics  naming/grouping living and fossil organisms
 each organism given a unique scientific name.
 mountain lion, panther, puma, cougar:
common names for Felis concolor.
 England: buzzard = hawk
United States: buzzard = vulture
 grouped by evolutionary relationships
 related by common descent
Binomial
nomenclature  developed by Carolus Linnaeus in 1730’s
Examples
Taxonomy
7 levels
Problems
 each species assigned a 2 part Latin name.
 Genus species
 italicized or underlined.
 Genus: capitalized species: lower case
 Animal
 Ursus arctos = Grizzly bear
 Ursus maritimus = Polar bear
 Ailuropoda melanoleuca = Giant panda
 Plant
 Acer saccharum = Sugar maple
 Acer rubrum = Red Maple
 Quercus alba = White oak
 groups species based on shared characteristics.
 kingdom, phylum, class, order, family, genus, species.
 King Philip Can Order Funny Green Socks
 each level is a taxon!
 species: groups of interbreeding organisms.
 researchers define family, order, class, etc.
 which characteristics are the most important?
Modern Evolutionary Classification
Phylogeny
 group species by evolutionary descent
 common ancestors
 NOT just physical characteristics
 some organisms look alike (dolphin, shark)
but are not closed related.
Clade
 group of living and fossil species
 common ancestor and all descendent
 monophyletic group: must include all and
only species descended from ancestor
Cladograms
Derived
character
DNA
sequences
 shows how species are related
 closer together; separated into species
more recently.
 nodes: speciation events
 lists characteristics that are different.
 trait that is shared by all members of a clade.
 more similar DNA = more recent common
ancestor
 more DNA differences = common ancestor
farther in past.
 can help redraw cladograms.
 giant panda classified with red panda and
raccoon.
 giant panda shares ancestor with bears.
Tree of life
Bar-coding
life
 DNA sequence
 animals: part of mitochondria CO1 gene.
 plants: part of chloroplast gene
 stored as bar codes in data base
 used for ID
 shows evolutionary relationships