Transcript Classification of Living Things

Classification of Living Things
Why do we classify things?
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Supermarket aisles
Libraries
Classes
Teams/sports
Members of a family
Roads
Cities
Money
What is classification?
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Classification: putting things into orderly groups
based on similar characteristics
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Taxonomy: the science of describing, naming, and
classifying organisms according to their
characteristics and evolutionary history
Early classification
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Aristotle grouped everything into
simple groups such as animals or plants
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He then grouped animals according to if they had
blood or didn’t have blood, and if they had live young
or laid eggs, and so on…
Modern Classification System
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Developed by Carolus
Linnaeus
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Swedish Biologist 1700’s
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Grouped organisms into
hierarchical categories
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Starts broad and ends
specific
Modern Taxonomy
The Evidence used to classify into taxon groups
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1) Embryology
2) Chromosomes / DNA
3) Biochemistry
4) Physiology
5) Evolution
6) Behavior
The modern system of classification has 8
levels:
 Domain
 Order
 Kingdom
 Family
 Phylum
 Genus
 Class
 Species
Helpful way to remember the 8 levels
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Dumb kids playing catch on freeways get squashed
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Or…make up your own…
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DKPCOFGS
Scientific Names:
Binomial Nomenclature
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An organism’s genus is always written first; the
organism’s species is always written second
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The genus is Capitalized; the species is
written in lower case
Homo sapiens
Representing Evolutionary Relationships:
Phylogenetic Tree:
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Family tree showing evolutionary history
- shows relationships thought to exist between groups or
organisms
Representing Evolutionary Relationships:
Cladogram:
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Uses shared derived traits
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Derived traits indicate divergence from a common
ancestor