Biological Classification
Core Objectives:
 Understand that there is great variety in life
 Classifying Species
o Understand the importance of classification
o Scientific Name / Binomial Nomenclature
o 4 Main ways to classify a species from another
o Why scientist sometimes change the classification of a species
 Hierarchical Classification
o Memorize Level Order
o Understand how levels can be used to infer similarity and shared ancestry
o Disadvantages
 Phylogenic Trees & Cladograms
o Trees of life show evolutionary history (branching points / speciation events / derived characters)
o Dichotomous Keys
 Major Taxa
o Archae
o Bacteria
o Eukarya
 Protista
 Fungi
 Plantae
 Animalia
Domains
Kingdoms
Archae
Bacteria
Eukarya
Protista
Fungi
Animalia
Plants
Prokaryotic
vs.
Eukaryotic
Unicellular
vs.
Multicellular
Type of Metabolism
(How they get energy)
Examples
Major
Characteristics
Key Terms
Biodiversity
13 Billion Species estimated
5% of actually named
Tropics have most
Many of unnamed are microscopic
New organisms found every day
Evolution still happening
Species
Ecological / Biological Test (Interbreeding)
Morphological Test
Niche Test
Molecular Test
Early Taxonomy
Aristotle  Classification by complexity and role/habitat
John Ray  Latin names
Linnaeus  Binomial Nomenclature
Genus
Species
Scientific Names
Rules
Genus first, then species
Genus is capitalized
Species is lowercase
Latin or sometimes Greek
Always italicized or underlined
If anything greater than genus is specified, it is capitalized, but not italicized
Acceptable Structure
Genus species
G. species
Genus species
G. species
Examples
International Code for Binomial Nomenclature
International Naming Congress
Reasons to Use Scientific Names
Avoiding Confusion (Accuracy & Uniformity)
Avoiding Ambiguity (Misnomers) in Classification
“Fishes”: jellyfish (cnidarian), crayfish (crustacean), silverfish (insect)
Standardization
Provide insight into relationships between animals
Example: Animals sharing genus are closer than animals sharing family
Hierarchical classification
Taxons
Linnean Taxonomy
Kingdom
Phylum
Class
Order
Family
Genus
Species
Modern Taxonomy
Subcategories
Domains
Advantage
Taxa & Hierarchical similarity
Disadvantage
Differences in levels of similarities / differences for animals in different equivalent levels
Lack of insight into evolutionary process / history
Phylogeny
Phylogenic Trees
Branching Points
Dichotomous Keys (Two-way split guides)
Phylocode (Path on tree) vs. Taxa
Relationships
Rooting
Basal Taxon
Sister Taxa
Polytomy
Advantages
Establish evolutionary relationships & history
Links to hierarchical taxa
Consideration of derived characteristics
Disadvantages
No information on rate of evolution
Age of animals
Easy to confuse common origin with origin from each other
Hypothesis of Evolutionary Relationships
Systematics
Morphology / Physiology
Ecological Role / Behaviors
Paleontology
Molecular Biology (DNA / RNA / Polypeptide sequence)
Analogy (Homoplasies) vs. Homology (Molecular  Organism)
Fossil Evidence
If common ancestor does not have trait = analogous
Great degree of similarity in extremely complex structures  homologous
Phylogenetics
Cladistics
Clades
Common Ancestry
Monophyletic
Paraphyletic
Polyphyletic
Shared characteristics (homologous structures)
Shared derived character (Branching points)
Ingroup vs. Outgroup
Proportional Phylogeny & Cladistics
Genome as Evolutionary Library
Orthologous genes
Paralogous
Gene variety vs. phonotypical variety
Molecular Clocking
Using mutation rates to estimate time since evolutionary splits
Calibration with fossil record
Disavantage
Possibility for variable rates or burst evolution
Rate is an estimation based on average only
Fossil record limitations
Natural selection & mutation rates
Genes & Evolution vs. clock speed
Neutral = constant rate and fast
Crucial = slower rate and variable
Examples of Ticking Speeds
rRNA  Slowest to mutate (ancient splits)
mtDNA  Faster to mutate (recent speciation)
Using multiple genes to clock
Branch Lengths & Evolutionary History
Constructing Trees
Maximum Parsimony (Fewest evolutionary splits)
Maximum Likelihood (Most common)
Hypothesis of Evolutionary Relationships
The Three Domains System & The Tree Life
The Problem with Prokaryotic vs. Eukaryotic Cells Taxonomy
Changes to old system
Old Kingdom Monera  Archae & Eubacteria
Current Domains
Archea
Bacteria
Eukarya  Protista; Fungi; Plants; Animals
Tree of Life vs. Ring of Life
Horizontal Gene Transfer
Conjugation
Viral Transduction
Organism Fusion
Endosymbiosis
The Main Taxa of Life [Know any major characteristics discussed in the videos]
Archea
Bacteria
Eukarya
Protista
Fungi
Plants
Moss-like (Nonvascular)
Ferns-like (Seedless vascular)
Gymnosperms (Seed vascular)
Angiosperms (Flowering plants)
Animals
Invertebrates
Porifera
Cnidarians
Platyhelminthes
Nematoda
Rotifera
Annelida
Mollusca
Arthropoda
Echinodermata
Chordata
Invertebrate Chordates
Tunicates
Lancelates
Vertebrata
Jawless fish
Cartilaginous fish
Bony fish (Ray & Lobe finned)
Amphibia
Reptilia
Mammalia
Aves
Major Animal Derived Characters
Multicellularity
Ingestive Heterotrophs
Levels of Organization (Atom, Molecules, Organelles, Cells, Tissue, Organ, Organ System, Organism)
Embryonic Development (Cleavage, Morula, Blastula, Gastrulation, Gastrula, Blastopore, Blastocoel, Archenteron, Mesoderm)
Tissue Layers: No Tissue vs. Diploblastic (Endo vs. Mesoderm) vs. Triploblastic (Endoterm, Mesoderm, Ectoderm)
Gastro-cavities (Two-way vs. one way)
Body Plans
Acoelomate
Pseudocoelomate
Coelomate
Symmetry
Asymmetric
Radial
Bilateral
Cephalation
Deuterostomes vs. Protostomes
Segmentation
Appendages