Post on 18-Dec-2015
Animal Classification, Phylogeny, and Organization
Cladistics & Taxonomy
Animal Systematics The goal of animal systematics is to arrange animals into groups that
reflect evolutionary relationships. How might you group the animals in
the picture? One way to group them is by using
phylogenetic systematics, otherwise
known as cladistics. Phylogeny refers to the evolutionary
ancestry of animals; how they are
related to a common ancestor. Cladistics uses the phylogeny of animals
to group them according to homologous
characters. Character – anything with a genetic basis that can
be measured, i.e., anatomy, morphology, or DNA
itself.
Cladistics Cladistics focuses on monophyletic groups. A monophyletic group refers to a single
ancestor species and all of its descendants. Diagrams called cladograms are used to
represent the phylogeny of organisms.
Characters Symplesiomorphy – a homologous character
shared by all members of a monophyletic group.
Synapomorphy – a derived character that has arisen after a symplesiomorphy visible in a given outgroup. Groups that share a certain synapomorphy are called a clade.
Cats are more similar to dogs than they are to frogs, because they share a more recent common ancestor with dogs
Practice Cladogram
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Construct a Cladogram
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Gorilla Chimpanzee
Tiger
Lizard
Fish
Four Limbs
Fur
Tail Lost
Cladogram Showing Vertebrate Phylogeny
Classification Organisms can be classified according to
their relatedness to other organisms. The accepted classifications among scientists
are called taxonomy. Taxonomy is a hierarchical system. This
means that you start very general and get more specific as you proceed down the list. Example - The grocery store is set up the same way!
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Kingdom
Phylum
Class
Order
Family
Genus
Species
Current Biological Classifications Kingdom King Phylum Philip Class Came Order Over Family For Genus Grape Species Soda
Example: Human Kingdom Phylum Class Order Family Genus Species
Animalia Chordata Mammalia Primates Hominidae Homo sapiens
Binomial Nomenclature Bi – 2 Nomen – name The first name is always the GENUS The second name is always the SPECIES Thus, our binomial nomenclature is homo
sapiens. The binomial nomenclature of a house cat is
felis catus. The binomial nomenclature of a killer whale is
orcinus orca.
Example: Dog Kingdom Phylum Class Order Family Genus Species Subspecies
Animalia Chordata Mammalia Carnivora Canidae Canis lupus familiaris
The 5 Kingdoms Kingdom:
Monera – true bacteria and cyanobacteria Protista – eukaryotic, unicellular or colonial,
usually motile, microscopic in size (amoeba, paramecium, etc.)
Plantae – eukaryotic, multicellular, photosynthetic, have cell walls, nonmotile
Fungi – eukaryotic, multicellular, decomposer, have cell walls, usually nonmotile
Animalia – eukaryotic, multicellular, heterotrophic, no cell walls, motile, specialized tissues