Transcript Animal Classification

Animal Classification
From Buckle Down Mississippi
Taxonomy
• Scientists believe that all life on the
Earth arose from an ancient singlecelled life-form.
• For this reason, all of the organisms that
have ever lived on the Earth are related
to each other—some distantly, and
some not.
• Biologists figure out how closely
different life-forms are related to each
other by comparing their characteristics
and putting them into groups.
Taxonomy
• Taxonomy is the science of naming
and classifying organisms based on
their similarities and differences.
• In the 1700s, the Swedish scientist
Karolus Linnaeus developed a
classification system for living things.
• His system involved grouping
organisms into seven levels—
kingdom, phylum, class, order, family,
genus, and species.
Taxonomy
• In this system, the level of kingdom is
the most general and contains the most
types of organisms.
• The level of species is the most specific
and contains only one type of organism.
• If you have trouble remembering the
order of the taxonomic groups, just
remember the phrase "Kings Play Chess
On Fat Green Stools”
• The first letter of each word will help
you recall the name of each level, in
order from most general to most specific
Taxonomy
• An example will make clear how the Linnean
system works. The following table shows
how the Linnean system classifies a polar
bear.
• The top level (kingdom) is the most general,
containing all animals including the polar
bear.
• The next level (phylum) is a little more
specific, including only those animals that
are vertebrates (have backbones).
Taxonomy
• Each level down gets even more specific,
excluding more and more types of
animals.
• The last level (species) contains only one
type of animal— Ursus maritimus, the
polar bear.
Taxonomy
Taxonomy
• Linnaeus used two Latin
names to describe an
organism's genus and
species.
• This method of naming
organisms is called binomial
nomenclature,
• a term that means "two-word
naming system."
Taxonomy
• Organisms that are similar may have the
same genus name but different species
names.
• A tame dog is Canis (dog) domesticus
(domestic), whereas the coyote is Canis
(dog) latrans (barking).
• Notice that the genus name is capitalized,
the species name is not capitalized, and
both names are in italics.
• When writing an organism's genus and
species name by hand, don't try to italicize
them—-just underline them.
The Kingdoms of Life
• Back in the 18th century,
Linnaeus only defined two
kingdoms: Plantae and
Animalia—plants and animals.
• Since Linneaus's time, scientists
have added other kingdoms to
the original two.
The Kingdoms of Life
• There are now five widely
recognized Kingdoms
– Monera
– Protista
– Fungi
– Plantae
– Animalia
The Kingdoms of Life
• Monera: Includes bacteria and blue-green
algae.
• Monerans have no nuclei
• These single celled, microscopic
organisms are the most abundant lifeforms on Earth.
• They also may have been the first:
• Scientists believe that photosynthetic
monerans helped to oxygenate the Earth's
atmosphere billions of years ago.
The Kingdoms of Life
• Protista: Includes amoebas, euglenas,
and algae.
• Protists can be single celled and
microscopic,
• but unlike monerans, they have
nuclei.
• They can also be multicellular,
• but unlike plants or animals, they lack
any specialized tissues and organs.
• They are commonly called protozoa.
The Kingdoms of Life
• Fungi: Includes mushrooms,
yeasts, and molds.
• Yeasts are single celled, but
most other fungi are
multicellular.
• Fungi decompose other
organisms, an important role
in maintaining a healthy
ecosystem.
The Kingdoms of Life
*Plantae: Includes mosses,
ferns, and trees.
*Plants are multicellular and
make their own food by
absorbing sunlight.
*They generally cannot
move about freely.
The Kingdoms of Life
• Animalia: Includes
microscopic animals,
shellfish, and humans.
• Like plants, animals are
multicellular, but they eat
other life-forms for their
nutrition.
• Most animals can move
about freely.
The Kingdoms of Life
• Today, there isn't solid
agreement about how many
kingdoms there actually are.
• For example, many scientists
argue that the kingdom Monera
should be broken into two
kingdoms:
• Archaebacteria ("ancient
bacteria") and Eubacteria ("true
bacteria").
The Kingdoms of Life
• Archaebacteria thrive in extreme
conditions—near volcanic vents under the
sea or in hot springs too salty for other lifeforms to survive.
• Many scientists believe that members of
the kingdom Archaebacteria resemble the
first organisms to evolve on the Earth.
• Members of the kingdom Eubacteria, in
contrast, live everywhere on the planet—in
water, in the air, in your body, and even on
the page you are reading right now.
Kingdom
Phylum
• Scientists use
similarities and
differences among
body plans and
internal structures to
organize the vast
diversity of life into
groups called phyla
(singular phylum).
Kingdom
Phylum
• All members of the phylum
Arthropoda, for example, have a
hard outer shell and jointed legs.
• Insects, spiders, and crabs are all
types of arthropods.
Kingdom
• All members of the
phylum Chordata
start out their lives
with a notochord—a
long, flexible rod that
runs along a central
nerve cord.
Phylum
Kingdom
Phylum
• In vertebrates, the
notochord develops into a
spinal column with
vertebrae.
• This flexible, tough spinal
column protects the
delicate nerve cord inside.
• Fish, amphibians, reptiles,
birds, and mammals are all
classes of vertebrates.