Download Taxonomy

Chapter 15
Classification
By Evil Mr.
Bleecker
The Diversity of Life
The Diversity of Life
• How many species of organisms on earth?
but first.…
What’s a species?
Species
• All individuals of a certain kind who are
able to interbreed
• Horses with horses, dogs with dogs, etc.
• Same number of chromosomes with similar
shaped chromosomes
Species:
Donkey x Horse
• Results in: a mule
• Therefore, are donkeys and horses the same
species?
• but.... Mules are sterile...
How many species on Earth?
Surprisingly, we have a better understanding of
how many stars there are in the galaxy than how
many species there are on Earth.
Estimates of global species diversity have varied
from 2 million to 100 million species, with a best
estimate of somewhere near 10 million.
Only 1.4 million have actually been named. The
problems stemming from the limits of current
knowledge of species diversity are compounded
by the lack of a central database or list of the
world's species.
How to organize all this?
• In 1700’s Linnaeus developed a
hierarchical classification system
• Originally, he divided all organisms
into 2 Kingdoms:
– Plants & Animals
• Then he subdivided each kingdom
into progressively narrower groups:
– Phylum, Class, Order, Family, Genus, &
species
Carl Linnaeus (1707-1778)
also known as Carl von Linné or
Carolus Linnaeus, is often
called the Father of
Taxonomy. His system for
naming, ranking, and
classifying organisms is still in
wide use today.
Classification System
Each and every species can now be classified by this system:
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• species
Five Kingdoms
Taxonomic Classification
• Kingdom-largest category. Includes all organisms that have one ore
more common features.
– The five common kingdoms:
•
•
•
•
•
Monera
Protists
Fungi
Plants
animals
Microorganisms-organisms that can only be seen with a microscope.
Monera (bacteria and cyanobacteria)
• Single celled, microscopic prokaryotic organisms.
• Play vital role as decomposers, breaking down
tissue of dead organisms into simpler compounds
that serve as nutrients for bacteria and are
eventually reused as nutrients by plants.
• Although bacteria can cause diseases in humans,
not all bacteria are bad.
Monerans are Prokaryotic Cells
• Bacteria cells
• Surrounded by a membrane
but have no distinct nucleus or
other internal parts enclosed
by membranes.
Protists (protista)
• Mostly single celled eukaryotic organisms.
• Some cause human diseases such as malaria
and sleeping sickness.
• Protists include: diatoms, dinoflagellates,
amoebas, golden brown and yellow-green algae,
and protozoans.
Fungi
• Mostly many celled
eukaryotic organisms.
• Many are decomposers.
• Some kill various plants
and cause loss of crop
and trees.
• Fungi include:
mushrooms, molds,
mildews, and yeasts.
Plants (plantae)
• Mostly many celled eukaryotic organisms.
• Have
– Cell Walls of cellulose
– Central water vacuole
– Chloroplasts
Animals (animalia)
• Many celled, eukaryotic organisms.
• Two types:
– Vertebrates-animals with backbones and a brain
protected by skull bones (ex: fishes, amphibians,
reptiles, birds, mammals)
– Invertebrates-have no spine (ex: sponges, jellyfish,
worms, arthropods (insects, shrimp, spiders),
mollusks (snails, clams, octopuses), echinoderms
(sea urchins and sea stars)
Binomial System
• For ease of classification & recognition, we
normally use only the last 2 names (Genus,
species) to describe a species:
Homo sapiens
Pinus ponderosa
Escherichia coli
Gorilla gorilla
The Kingdoms of Life
Linnaeus created 2 Kingdoms
What’s missing?
Today it is common to use 6 Kingdoms
The 6 Kingdoms of Life
Animals
Plants
Fungi
Protists
Bacteria
Archaea Bacteria (ancient bacteria)