2. Why Classify
Why Classify
• Biologists want to better understand
Biologists want to better understand
organisms so they organize them.
organisms so they organize them.
• One tool that they use to do this is
One tool that they use to do this is
classification
classification—the grouping of objects or
—the grouping of objects or
information based on similarities.
information based on similarities.
• Taxonomy
Taxonomy is the branch of biology that groups
is the branch of biology that groups
and names organisms based on studies of their
and names organisms based on studies of their
different characteristics.
different characteristics.
• Biologists who study taxonomy are called
Biologists who study taxonomy are called
taxonomists.
taxonomists.
3. Keeping track of species
Keeping track of species
• >1 million species named, up to 15 million more.
>1 million species named, up to 15 million more.
• Taxonomy is not new; cultures have been
Taxonomy is not new; cultures have been
naming plants and animals around them for
naming plants and animals around them for
1000’s of years.
1000’s of years.
• It’s practical to have names.
It’s practical to have names.
• The Greek philosopher Aristotle (384-322 B.C.)
The Greek philosopher Aristotle (384-322 B.C.)
developed the first widely accepted system of
developed the first widely accepted system of
biological classification.
biological classification.
• He classified all the organisms he knew into two
He classified all the organisms he knew into two
groups: plants and animals.
groups: plants and animals.
4. Which one is easier?
Which one is easier?
“
“Watch out—there’s a
Watch out—there’s a bear
bear behind that rock!
behind that rock!
OR
OR
“
“Watch out--there is a
Watch out--there is a large, furry, four-legged
large, furry, four-legged
creature with long claws, a big mouth set
creature with long claws, a big mouth set
in a short, stout muzzle, attached to a
in a short, stout muzzle, attached to a
round head containing small eyes and
round head containing small eyes and
short triangular ears
short triangular ears behind that rock!”
behind that rock!”
5. Q. What is the largest wild felid (cat)
Q. What is the largest wild felid (cat)
in the United States?
in the United States?
Mountain Lion
Mountain Lion
Cougar
Cougar
Panther
Panther
Painter
Painter
Puma
Puma
Catamount
Catamount
7. Who devised a system
Who devised a system
for classification?
for classification?
• Carolus Linneaus (1707 -1778)
Carolus Linneaus (1707 -1778)
a swedish naturalist.
a swedish naturalist.
• Devised a two part naming
Devised a two part naming
system known as binomial
system known as binomial
nomenclature.
nomenclature.
8. Binomial Nomenclature
Binomial Nomenclature
• Standard two-part system for naming things.
Standard two-part system for naming things.
• In this system, the first word identifies the
In this system, the first word identifies the
genus of the organism.
genus of the organism.
• A genus (genera-plural) consists of a group of
A genus (genera-plural) consists of a group of
similar species.
similar species.
• The second word, which sometimes describes
The second word, which sometimes describes
a characteristic of the organism, is called the
a characteristic of the organism, is called the
specific epithet.
specific epithet.
Linnaeus described and named > 6,000 animals
Linnaeus described and named > 6,000 animals
and >4,000 plants using Latin
and >4,000 plants using Latin
Scientific name does not replace, but instead
Scientific name does not replace, but instead
further defines common name
further defines common name
9. • Scientific names should be italicized in print
Scientific names should be italicized in print
and underlined when handwritten.
and underlined when handwritten.
• Taxonomists are required to use Latin
Taxonomists are required to use Latin
because the language is no longer used in
because the language is no longer used in
conversation and, therefore, does not change.
conversation and, therefore, does not change.
• The first letter of the genus name is
The first letter of the genus name is
uppercase, but the first letter of the specific
uppercase, but the first letter of the specific
epithet is lowercase.
epithet is lowercase.
Passer domesticus
Passer domesticus
Scientific and common names
Scientific and common names
10. • Even though the genus and species
Even though the genus and species
are thorough sometimes more is
are thorough sometimes more is
needed.
needed.
• Varities are splits of species. Example
Varities are splits of species. Example
peaches & nectarines are both from a
peaches & nectarines are both from a
peach tree.
peach tree.
• Subspecies are variations of species
Subspecies are variations of species
that occur in different regions.
that occur in different regions.
11. May tell you where it was first discovered:
– Didelphis virginiana “2 wombs from Virginia”
– Sylvilagus floridanus “wood-hare of Florida”
Or who discovered it:
– Lepus townsendii “hare” discovered by
“Townsend”
12. • Grouping organisms on the basis of their
Grouping organisms on the basis of their
evolutionary relationships makes it easier to
evolutionary relationships makes it easier to
understand biological diversity.
understand biological diversity.
Modern Classification
• Expanding on Linnaeus’s work, today’s
Expanding on Linnaeus’s work, today’s
taxonomists try to identify the underlying
taxonomists try to identify the underlying
evolutionary relationships of organisms and
evolutionary relationships of organisms and
use the information gathered as a basis for
use the information gathered as a basis for
classification.
classification.
• Taxonomists group similar organisms, both
Taxonomists group similar organisms, both
living and extinct. Classification provides a
living and extinct. Classification provides a
framework in which to study the relationships
framework in which to study the relationships
among living and extinct species.
among living and extinct species.
13. How Living Things Are Classified
How Living Things Are Classified
• In any classification system, items are
In any classification system, items are
categorized, making them easier to find and
categorized, making them easier to find and
discuss.
discuss.
• Although biologists group organisms, they
Although biologists group organisms, they
subdivide the groups on the basis of more
subdivide the groups on the basis of more
specific criteria.
specific criteria.
• A group of organisms is called a taxon (plural,
A group of organisms is called a taxon (plural,
taxa).
taxa).
• Organisms are ranked in taxa that range from
Organisms are ranked in taxa that range from
having very broad characteristics to very specific
having very broad characteristics to very specific
ones.
ones.
• The broader a taxon, the more general its
The broader a taxon, the more general its
characteristics, and the more species it contains.
characteristics, and the more species it contains.
15. Taxonomic rankings
Taxonomic rankings
• The smallest taxon is species. Organisms
The smallest taxon is species. Organisms
that look alike and successfully interbreed
that look alike and successfully interbreed
belong to the same species.
belong to the same species.
• The next largest taxon is a genus—a group of
The next largest taxon is a genus—a group of
similar species that have similar features and
similar species that have similar features and
are closely related.
are closely related.
16. • Compare the appearance of a lynx,
Compare the appearance of a lynx, Lynx rufus,
Lynx rufus,
a bobcat,
a bobcat, Lynx canadensis
Lynx canadensis, and a mountain
, and a mountain
lion,
lion, Panthera concolor
Panthera concolor.
.
Lynx Mountain
lion
Bobcat
Taxonomic rankings
Taxonomic rankings
17. Taxonomic goals
Taxonomic goals
Place organisms into logical categories
– system must be capable of being used for
information retrieval, so anyone can
properly identify any organism
Place organisms into categories that
show ancestor-descendant
relationships
18. Taxonomic hierarchy
Taxonomic hierarchy
Kingdom (Animalia)
Phylum (Chordata)
Class (Mammalia)
Order (Carnivora)
Family (Canidae)
Genus (Canis)
Specific epithet (species) (familiaris)
Scientific name: Canis familiaris
21. • The evolutionary history of a species is called its
The evolutionary history of a species is called its
phylogeny
phylogeny.
.
Phylogenetic Classification: Models
Phylogenetic Classification: Models
• A classification system that shows the
A classification system that shows the
evolutionary history of species is a
evolutionary history of species is a phylogenetic
phylogenetic
classification and reveals the evolutionary
classification and reveals the evolutionary
relationships of species.
relationships of species.
• One biological system of classification that is
One biological system of classification that is
based on phylogeny is cladistics.
based on phylogeny is cladistics.
• Scientists who use cladistics assume that as
Scientists who use cladistics assume that as
groups of organisms diverge and evolve
groups of organisms diverge and evolve
from a common ancestral group, they retain
from a common ancestral group, they retain
some unique inherited characteristics that
some unique inherited characteristics that
taxonomists call derived traits.
taxonomists call derived traits.
23. Kingdom Archaebacteria
Kingdom Archaebacteria
• Unicellular, Prokaryote
• Either autotroph or
heterotroph
• Cell walls made of
peptidoglycan
• Reproduces by binary
fission
• Lives in Harsh
environments: salty lakes,
hot springs, anaerobic
environments
• AKA–Kingdom Moneran
24. Kingdom Eubacteria
Kingdom Eubacteria
• Unicellular, prokaryote
• Either autotroph or
heterotroph
• Cell walls made of
peptidoglycan
• Reproduces by binary
fission
• Includes common bacteria:
tooth decay, yogurt
production, food poisoning
• AKA–Kingdom Moneran
25. Kingdom Protista
Kingdom Protista
• Unicellular or multicellular
• Eukaryotic
• Cell walls made of varying
materials
• Autotroph or heterotroph
• About 50,000 species
• Reproduces-asexually
• Examples include:
– Euglena
– Amoeba
26. Kingdom Fungi
Kingdom Fungi
• Unicellular or multicellular
• Eukaryotic
• Heterotrophic
• Cells walls made of chitin.
• Reproduces - asexually
• 100,000 species
• Including: toadstools,
mushrooms, puffballs,
rusts or smut
27. Kingdom Plantae
Kingdom Plantae
• Multicellular
• Eukaryotic
• Autotrophic
• Can reproduce both
ways.
• Cell walls made of
cellulose.
• All but a few are land
dwellers. 350,000
species
• Including:mosses, ferns,
conifers, flower plants
28. Kingdom Animalia
Kingdom Animalia
• Multicellular
• Eukaryotic
• Heterotrophic
• No cell walls
• Reproduces
sexually by meiosis.
• All animals have
some type of
symmetry
