Transcript Classification Systems

CLASSIFICATION
SYSTEMS
INTRODUCTION TO CLASSIFICATION
Taxonomy
 science of identifying and classifying organisms
Biological Classification
 organized grouping organisms into categories
 based on:
physical descriptions
 evolutionary relationships
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http://www.youtube.com/watch?v=kKwOlAqQoLk
CARL LINNAEUS
1707-1778
 Swedish scientist
 “father” of taxonomy
 classified organisms based
on their physical
similarities
 established the current
binary naming system used
to name species
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TRADITIONAL CLASSIFICATIONS
based on human philosophical conclusions on the
complexity of organisms called “scala naturae”
 based on the belief that species do not change or
evolve
 organized in the following way:
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humans
mammals and birds
frogs and fish
worms and insects
plants
TRADITIONAL TAXONOMIC LEVELS
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taxon – category used in
classification
species – group of organisms that
mate naturally and produce healthy
offspring
genus – group of species that share
similar features
family – group of genera that share
similar features
order – group of families that share
similar features
class – group of orders that share
similar features
phylum – group of classes that
share similar features
kingdom – group of phyla that share
similar features
Humans
Kingdom – Animalia
Phylum – Chordata
Class – Mammalia
Order – Primates
Family – Hominidae
Genus – Homo
Species – Homo
sapiens
Examples – pg 17
BINARY NOMENCLATURE
formal naming system developed by Linnaeus
 species are named using their genus name
followed by their specific name
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genus name is capitalized
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Homo
specific name is not capitalized
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Homo sapiens
sapiens
both genus and specific names are italicized
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Homo sapiens
Examples – pg 17
DICHOTOMOUS KEYS
used to identify species
 series of branching two part statements
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Create a
dichotomous
key using
the
following
footprints.
DICHOTOMOUS KEY – PLANT
IDENTIFICATION
PHYLOGENY
science of evolutionary relationships between
species
 based on the theory of evolution
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all living things are descended from a common
ancestor
 species are able to change/evolve over time
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Examples – pgs 22-23
PHYLOGENETIC TRESS
diagram representing evolutionary relationships
between different species
 created using fossil records and similarities in
genetic codes
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Clade is a group of
species that include a
single common ancestor.
Clades vary in size. A
large clade can include
smaller clades.
THINK/PAIR/SHARE
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2.
Why are classification systems important in
biology?
What are some of the challenges in classifying
organisms?