Download History of Taxonomy 18-1

Classification
18-1 Finding Order in Diversity
Early Systems of Classification
Taxonomy –
A. Branch of biology that names and groups
organisms according to their characteristics
and evolutionary history.
B. First classification process occurred more
than 2000 years ago by Aristotle.
1. Either plant or animals, only!
a. Animals were either land
dwellers, water dweller, or air dwellers.
b. Plants were grouped based on
their stem differences.
C. In attempt to begin organizing organisms,
the classification process started by looking
at the physical appearance. The names
became too long and hard to remember,
suggesting nothing about how the
organisms were related to other organisms
.
D. This old system became inadequate and
was soon replaced.
E. Carolus Linnaeus (1707-1778) developed
a 2–word naming system called the
Binomial Nomenclature.
F. Linnaeus assigned binomials (2
names) to over 11,000 species of
plants and animals
G. Scientific name = genus,
species
1. First part – genus is a
group of closely related species.
ex. Bears - Ursus
2. Second part – species is unique to
the species within the genus.
ex. Polar– maritimus
• Species within a genus should be
more similar to each other than to
other species.
H. The first letter of the Genus
is capitalized and both are
written in italics.
I. Species names are in Latin
so that they are the same in
any language.
1. Closes communication
gaps between different
countries with different
languages.
J. His grouping of organisms
went into a hierarchical system,
using form and structure to
categorize.
K. Levels of Classification
A. 7 levels, each level are
called a taxon or taxonomic
category.
I. Kingdom- largest, most
inclusive
A. Phylum/division –
subject within a kingdom,
made of several classes.
1. Phylum = animal
kingdom
2. Division = plant
kingdom
.
a. Class – composed of similar
orders.
b. Order – composed of similar
families.
c. Family – group of genera that
share many characteristics.
d. Genus – group of closely
related species.
e. Species – group of similar
organisms that can breed.
L. Subspecies – zoologists refer to
variations of a species that
occur in different geographic
areas.
1. The Latin name is then
written as:
Genus species subspecies