Transcript Classification of Living Things

Classification of Living Things
Taxonomy
Taxonomy
• Definition:
– The branch of biology that deals with the
classification and naming of living things
Early Attempts at Classification
• Aristotle
– animals
– based groupings on habitats
• air-dwellers, land-dwellers, water-dwellers
• Theophrastus
– plants
– groupings on stem structure
• herbs (soft stems), shrubs (several woody
stems), trees (one woody stem)
• Exploration & Microscopes made these
two methods obsolete!
Early Attempts at Classification
• John Ray
– advanced classification via plant studies
– first to use term species
• Carolus Linnaeus
– father of modern taxonomy
– developed hierarchy of classification based
upon structural similarities
– methods are still in use today
Classification Categories
• Animal Taxonomy
– Kings Play Chess On Fine Green Silk
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Kingdom
Phylum
Class
Order
Family
Genus
Species
• Plant Taxonomy
– Division replaces Phylum
Binomial Nomenclature
• Definition: a system for naming organisms
based upon two words
• Naming of organisms used to be extremely
confusing
– many organisms had multiple, multiple names
• Linnaeus “streamlines” by giving each
organism a Genus and species name
– i.e., Homo sapiens
• Eliminates the confusion of so-called
“common naming”
Modern Taxonomy
• Theory of Evolution serves as the basis for
modern taxonomic methods
– Species: group of like individuals who can
breed with each other and produce fertile
offspring
• species separated for periods of time become
different species base upon mutations
• Phylogeny
– evolutionary history of a species or a group of
organisms
– similar to a family tree
Human
Phylogenic
Tree
Another
Human
Phylogenic
Tree
What Things Do We Use to Classify?
• Structural Information
– skeletal, leaves, etc.
• Biochemical Information
– DNA, RNA, protein structure, etc.
• Cytological Information
– cell structure, chromosome number, etc.
• Embryological Information
– structure in early stages of develpment
• Behavior Information
– mating calls in crickets, etc.
What are the Kingdoms?
• “Old School”
(Kingdoms)
– Monera
– Protista
– Fungi
– Plantae
– Animalia
• “New School”
(Domains)
– Archaebacteria
– Eubacteria
– Eukaryote
• Protista
• Fungi
• Plantae
• Animalia
Archaebacteria
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Live in hostile environments
Most in oxygen-free environments
Unicellular & prokaryotic
Examples
– Methanogens
– Halophiles
– Thermoacidophiles
Eubacteria
• Make up the majority of modern
bacteria
• Most are unicellular
– chains or colonies
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Prokaryotic
Most heterotrophic
Disease-causing
Cyanobacteria
Protista
• Most are unicellular
– some colonial and
multicellular
• Eukaryotic
• Heterotrophic are
protozoa
• Phototrophic are algae
Fungi
• Includes molds, yeasts, mushrooms,
etc.
• Function as either parasites or
decomposers of dead matter
• Most multicellular, some unicellular
• Eukaryotic
• Have cell walls but of different chemical
structure than plants (chitin v. cellulose)
• Cannot photosynthesize
• Eat like flies!
Various Fungi
Plantae
• Include mosses, ferns, liverworts, and seed
plants
• All have cell walls as part of cell structure
• Most all are photosynthetic
Animalia
• More species in
this kingdom than
all others
• All are multicellular
with a higher level
of organization
Animal Phyla
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Porifera
Cnidaria
Platyhelminthes
Nematoda
Annelida
Mollusca
Arthropoda
Echinodermata
Chordata
Porifera
• Includes the sponges
Cnidaria
• Includes two body forms,:
– polyp
– medussa
Platyhelminthes
• Flatworms
Nematoda
• The Roundworms
Annelida
• Segmented
worms
Mollusca
• Mollusks
– clams, snails slugs
Arthropoda
• Segmented bodies, exoskeletons
– crustaceans
– centipedes
– millipedes
– spiders
– insects
Echinodermata
• Starfish
• Sea urchins and cucumbers
• Sand dollars
Chordata
• Spinal cord