Post on 18-Dec-2015
FIELD BIOLOGY
THE CLASSIFICATION
SYSTEM
BIOLOGY
Bios (Greek) =
Logos (Greek) =
Life
Study
BIOLOGY
- ZOOLOGY
- BOTANY
Two Sub-fields:
BOTANY
Botane (Greek) =
Logos (Greek) =
Plant
Study
ZOOLOGY
Zoon (Greek) =
Logos (Greek) =
Animal
Study
TAXONOMYOriginal classification schemes:
- were based on the idea of “fixity of species”.- were based on similar external features.
Carolus Linnaeus- first to catalog organisms based on thefunction of a structure.
Carolus Linnaeus 1707-1778
Carolus Linnaeus- later others added theorigin of the structure as acriteria.
Carolus Linnaeus 1707-1778
- Was the structure from independent evolution?
Origin of a structure
Euphorbia – African Desert
Cactus – Mexican Desert
- Or was it from a common ancestor?
Origin of a structure
Ostrich - Africa Rhea – S. America
Is the structure anAnalogous structureor anHomologousStructure?
- different internal structure
Analogous Structures
- no common evolutionary origin
- have similar functions
- have a similar evolutionary origin
Homologous Structures
- but may have different functions
The modern Linnaean system assumes that the more homologies two species share…the closer they must bein terms of evolutionarydistance.
The closer they are in terms of evolutionary distance… the more likely they should be in similar classification groups.
Linnaean System• Kingdom
• Phylum• Class• Order• Family• Genus• Species
- Animalia
- Chordata- Mammalia- Primates- Hominidae- Homo- sapiens
Kingdoms?
In Ancient times:
1 Animalia
Woof !
Kingdoms?
In Ancient times:
1 Animalia
2 Plantae
Kingdoms?
By 1969 we had . . .
1 Animalia2 Plantae3 4 Protista5 Monera
3 Fungi
Kingdoms?
Today:
1 Animalia2 Plantae
3 Fungi4 Protista
6 Eubacteria5 Archaebacteria
1 - 4 = Cell Type?5 - 6 = Cell Type?
1 - 4 = Eukaryotic5 - 6 = Prokaryotic
6 ?5 ?
Archaebacteria Eubacteria
Anerobic
Archaebacteria Eubacteria
Plantae Animalia Fungi
Protista
Animal-like Protists Fungus-like ProtistsPlant-like Protists
Archaebacteria Eubacteria
Plantae Animalia Fungi
Protista
Animal-like Protists Fungus-like ProtistsPlant-like Protists
Archaebacteria Eubacteria
Order
Family Family
Genus Genus Genus Genus
Species
Species
Species
Species
Species
Species
Species
Species
Kingdom
Phylum
Class
Binomial Nomenclature
- Two Latin Names; genus & species, to designate each type of organism
Species name:
ex: Homo sapiens, or
"man who is wise"
Homo is our genus
sapiens is our species
- if two organisms can mate and produce fertile offspring, they are probably members of the same species.
Define “Species” ?
A few thoughts about life over the long term. . .
Supernovas can occur approx. every 50,000 years and can bombard this planet with up to 700 roentgens of radiation.
Most forms of life can not survive over 500 roentgens.
99% of all plant and animal species that have ever existed on this planet have already become extinct.
Large animals, including humans, are freakishly rare life forms, since 99% of all known animal species are smaller than bumble bees.
Just THINK about that for a moment...