Download Classification101

Classifying Nature
Linnaeus, Buffon, Cuvier, Whittaker
Linnaeus
(Carl von Linnae, 1707-1778)
•
Swedish naturalist
who studied
medicine in the
Netherlands.
•
Main concern was
naming and
classifying natural
objects.
•
Studied plants in
Dutch gardens that
had been collected
from around the
world.
Linnaeus
•
Journeyed to Lapland to
study the animals and
plants, later published
Flora Lapponica in 1737.
•
Soon after his return,
Linnaeus was offered a
position as house
physician and garden
curator to George Clifford,
a wealthy merchant.
Linnaeus
•
1735: Linnaeus published Systema Naturae, his
first system for ordering natural history. He
admitted that it was an “artificial” rather than a
“natural” system, but felt that its utility justified
using a less natural system.
•
Linnaeus’ choice of terms reflect his cultural
background. Referred to plant stamens as andria
(“husband”) and pistils as gynia (“wife”). His
writings refer to “marriages” between plants,
including multiple spouses and concubines.
Shocking to other Dutch naturalists, but his
terms were adopted nevertheless.
Linnaeus
•
1736: Linnaeus formally publishes his system of
binomial nomenclature. Proposes that all natural
objects, including plants, animals, minerals, etc.
receive a single name consisting of a genus and a
specific epithet.
•
1753: Linnaeus publishes the Species Plantarum,
a description and classification of known
organisms. Included are human beings, given the
species name Homo sapiens. Interestingly,
Linnaeus also placed the known great apes in
genus Homo.
Georges-Louis LeClerk, Compte de
Buffon
•
1707-1788
Buffon was a competitor
of Linnaeus, advocating
for the development of a
natural system of
classification.
Buffon
•
Buffon’s taxonomy was based on “natural
families.” He noted, for example, that wolves,
foxes, and dogs all have similar features, and
constitute a natural family. Horses, zebras, and
donkeys would belong to a different natural
family.
•
Later Buffon would propose an early theory of
evolution, describing how organisms could change
by their environment into similar species within
the same natural family.
Georges Cuvier
1769-1832
Studied Buffon, and agreed that
there should be a natural
taxonomy.
However, Cuvier parted with
other taxonomists at the time, as
he believed the taxonomic
system should not be
hierarchical.
Cuvier
• Cuvier used internal anatomy of animals to
sort them into categories, based mainly on
neural anatomy: Vertebrata, Mollusca,
Articulata, and Radiata.
• Comparative anatomist: looking for patterns
in structure, especially among vertebrate
animals.
The Two Kingdom System
• Linnaeus’ two-kingdom system for living
organisms was practical for naturalists
working in the field, and eventually took
precedence.
• In this system, all living organisms are
classified as Animals or Plants (the Mineral
kingdom encompassed the non-living part of
the world). As time went on and
microorganisms were studied more, problems
arose with the two-kingdom system. Some
organisms just didn’t fit neatly.
Robert Whittaker
(1920-1980)
• Dissatisfied with the two-kingdom
system, as many single-celled
organisms didn’t fit well in it.
• For example, Euglena has
chloroplasts and photosynthesizes
like a plant, but is motile and can
ingest food like an animal.
• Developed first a three-kingdom,
then four-kingdom and fivekingdom systems.
Today’s System
• Recently, Domains were added above the level
of kingdom to express how different the two
large groups of bacteria are from one another.
• Domains:
• Archaea
• Bacteria
• Eukarya: Protists, Fungi, Plants, Animals