Transcript owen classification

Classification?
 Animals
are separated into
groups or categories so that
they are more easily studied
and discussed by scientists
and others.
The science of
organizing and
classifying organisms.
 Scientist
have identified over 2.5
million plus species of organisms
thus far.
 To help us work with the diversity
of life, we need a system of
biological classification that names
and orders living organism in a
logical manner.
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Early scientific names described
the physical characteristics of a
species in great detail and were
often 20 words long and was
difficult because scientist chose
different characteristics for the
same species
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Ex: “ Oak with deeply divided
leaves that have no hairs on their
undersides and no teeth around
their edges
Additionally scientist used common
names to describe organism
 This was also very confusing since
common names are the everyday
names given to organisms and may
not describe the organisms
accurately. EX. Robin, fir tree
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Jelly fish…not really a fish
No
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Catfish is not a cat
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Dogfish is a shark not a dog
Sometimes the same
common name was used
for different species.
 Ex. Maple: silver maple,
red maple, sugar maple
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In the USA, trees may
have different names in
different regions of the
country.
Ex. Same tree can be
called buttonwood, plant
tree, sycamore
 Aristotle
classified living
things as either
PLANT or
ANIMAL.
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He divided plants into 3
subcategorizes on the basis of Stem
differentiation.
Animals were subdivided into land
dwellers, water dwellers, and air
dwellers
 His
system
was favored
by scientists
until the
18th century
Or
a bird lands, or
a dog goes
swimming?
Problem:
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Problem: was that Aristotle's
categories did not accommodate all
the variations among living things.
No not unicorns!!
 German
Biologist
 Developed a 3rd
kingdom:
 Protista, in 18th
century
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1.
2.
3.
4.
5.
In 1969, R. H. Whittaker
developed a 5 kingdom system
which included:
Plants
Animals
Protist
Fungi
Monera/ Prokaryotes
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1.
2.
In 1978, Carl R. Woese proposed a 3
kingdom system including:
Prokaryotes into 2 kingdoms: a.
Eubacteria ( true bacteria),
Archaebacteria
All eukaryotes in one kingdom
Ditonomous key
Today all living organisms are
classified into one of five or six
existing kingdoms depending on
textbook used.
 The criteria used to define
kingdoms includes:
cell structure, tissue structure,
nutritional
requirements and developmental
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:
1. plant
2. Animal
3. Protist
4. Fungi
5. Monera/
Prokaryotae
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:
1. Plant
2. Animal
3. Protista
4. Fungi
5. Eubacteria( true
bacteria)
6. Archaebactera
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Single celled Prokaryotes (those
lacking a nucleus and membrane
bound organelles)
including bacteria and
cyanobacteria (blue-greenalgae)
gain their food as autotrophs or
heterotrophes
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single celled ( however a few are
multicellullar Eukaryotes (those
having a nucleus)
including paramecium, euglena ect...
gain their food as autotrophs or
heterotrophs
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Fungi: multicellular Eukaryotic
organisms ex mushrooms, get
their food as heterotrophs
Plantae:
multicellular
Eukaryotic autotrophs
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Multicelluar
Eukaryotic
heterotrophs
Unicellular .prokaryotes, no
membrane-bound organelles,
nutrients mainly by absorption
(heterotroph) but some are
autotrophs
 Include bacteria and
cyanobacteria
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Anaerobic and aerobic
prokaryotes that live in harsh
conditions ex extreme
temperatures, acidity or slat
content
 Examples are methanogens,
theromoacidophiles and extreme
halophiles
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Today Scientists use Carolus
Linnaeus's seven levels of
classification.
This is done since scientists often
classify species
into subspecies, varieties or strains to
denote
variations within a species.
 The
group to which Linnaeus
assigned organisms are called
TAXA.
 Thus the Science of naming
organisms and assigning them
to their groups is called
TAXONOMY.
The seven levels of
classification are as followed:
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KINGDOM (MOST GENERAL)
PHYLUM (DIVISION IN PLANTS)
CLASS
ORDER (suborders end in -ina)
FAMILY ( subfamilies end in -inae)
GENUS
SPECIES (MOST SPECIFIC)
NAMING A TAXON:
Use International Rules of
Zoological
Nomenclature:
 Each Genus and Species has a
name independent of change.
 Each Genus and species will have
separate names (no genus name
can be duplicated)
 Different names will not be
applied to one genus or species.
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NAMING A TAXON:
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Each genus and species must have a
primary name bearer.
Author citation : cite author's name
after taxon and first year
publication...If author's species
transfers to another genus then place
original author's name in parenthesis.
EVIDENCE USED IN
CLASSIFICATION
 Taxonomist
find evidence
for identification and
classification by
comparing chromosomes
of different organisms.
mushroom karyotype
 Ex.
2 similar mushrooms:study
karyotype for each by counting
chromosomes and comparing
chromosome shape...scientist
may determine whether the 2
mushrooms are closely related.
biochemical
comparisons
 Scientists
can also use
biochemical comparisons
of organisms to further
refine their classification
biochemical
comparisons
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Ex. E.coli and Enterobacter both
ferment lactose, but Enterobacter
uses citric acid as its sole source of
carbon and E. coli does not...but if
look at them under microscope they
look very similar.
breeding
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Ex. Scientific name Canis familiaris
once referred to the domestic dogs,
and Canis dingo to dingoes.
interbreed
 But
in 1993 the American
Society of Mammalologist
formally reclassified domestic
dogs as a subspecies of Wolf
(since they could interbreed
 Thus domestic dog is now:
Canis lupus familiaris

Ex. Fox while similar in appearance to
wolves, dogs ect is genetically
different having 36 chromosomes
instead of 78 and cannot interbreed
with dogs/wolves to produce fertile
offspring
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Ex. The horse and donkey may belong to different
species because they cannot interbreed to produce
fertile offspring (In some rare instances, a female
mule—the offspring of a horse and a donkey can
mate with a male horse to produce fertile
offspring, but this only occurs when the female
mule imparts only horse chromosomes to her
offspring (100% horse and not a horse-mule
hybrid) Horses have 19 chromosomes, donkeys
have 32 Horses are not interfetile with zebras
either
A
two part naming
system used to
identify organisms.
 Developed
a
system of
grouping
organisms into
hierarchical
categories
(Classification
Pyramid listed
above)
The seven levels of
classification are as followed:
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KINGDOM (MOST GENERAL)
PHYLUM (DIVISION IN PLANTS)
CLASS
ORDER (suborders end in -ina)
FAMILY ( subfamilies end in -inae)
GENUS
SPECIES
(MOST SPECIFIC)
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Rather than listing all seven
categories in naming an organism,
Linnaeus chose to use only the
genus and species names that
identify an organism (known as
the specific epithet).
 The
genus name is first and
capitalized followed by the
species name which is not
capitalized.
 Both are either underlined
or italicized.
Ex: Canis lupus or Canis lupus