FIELD BIOLOGY THE CLASSIFICATION SYSTEM. BIOLOGY Bios (Greek) = Logos (Greek) = Life Study

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...