THE CLASSIFICATION SYSTEM FIELD BIOLOGY THE CLASSIFICATION SYSTEM

BIOLOGY Bios (Greek) = Life Logos (Greek) = Study

BIOLOGY Two Sub-fields: - BOTANY - ZOOLOGY

BOTANY Botane (Greek) = Plant Logos (Greek) = Study

ZOOLOGY Zoon (Greek) = Animal Logos (Greek) = Study

TAXONOMY - were based on the idea of “fixity of species”. Original 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 the function of a structure. Carolus Linnaeus 1707-1778

Carolus Linnaeus - later others added the origin of the structure as a criteria. Carolus Linnaeus 1707-1778

- Was the structure from independent evolution? Origin of a structure - Was the structure from independent evolution? Euphorbia – African Desert Cactus – Mexican Desert

common ancestor? Origin of a structure - Or was it from a Ostrich - Africa Rhea – S. America

Is the structure an Analogous structure or an Homologous Structure?

Analogous Structures - have similar functions - different internal structure - no common evolutionary origin

- but may have different functions Homologous Structures - have a similar evolutionary origin - but may have different functions

The modern Linnaean system assumes that the more homologies two species share… the closer they must be in terms of evolutionary distance.

The closer they are in terms of evolutionary distance… the more likely they should be in similar classification groups.

Linnaean System Kingdom - Animalia Phylum - Chordata Class - Mammalia Order - Primates Family - Hominidae Genus - Homo Species - sapiens

Kingdoms? In Ancient times: 1 Animalia Woof !  

Kingdoms? In Ancient times: 1 Animalia 2 Plantae  

Kingdoms? 1 Animalia 2 Plantae 3 Fungi 3 4 Protista 5 Monera By 1969 we had . . . 1 Animalia 2 Plantae 3 Fungi 3   4 Protista 5 Monera

Kingdoms? 1 Animalia 3 Fungi 2 Plantae 4 Protista 5 Archaebacteria 5 ? 1 - 4 = Eukaryotic 5 - 6 = Prokaryotic Today: 1 Animalia 3 Fungi 2 Plantae 4 Protista 5. Eubacteria – true bacteria 6. Archaebacteria – bacteria-like (hot springs, sea vents, sewage plants & swamp sediments)   5 Archaebacteria 5 ? 6 ? 6 Eubacteria 1 - 4 = Cell Type? 5 - 6 = Cell Type?

Archaebacteria Eubacteria METAPROTOCELLS Anerobic

Archaebacteria Eubacteria METAPROTOCELLS

Archaebacteria Eubacteria Protista Plantae Animalia Fungi METAPROTOCELLS Protista Plant-like Protists Animal-like Protists Fungus-like Protists Plantae Animalia Fungi

Archaebacteria Eubacteria Protista Plantae Animalia Fungi METAPROTOCELLS Protista Plant-like Protists Animal-like Protists Fungus-like Protists Plantae Animalia Fungi

Kingdom Phylum Class Order Family Genus   Species    

Binomial Nomenclature - Two Latin Names; genus & species, to designate each type of organism

Homo is our genus sapiens is our species Species name: ex: Homo sapiens, or "man who is wise" Homo is our genus sapiens is our species

Define “Species” ? - if two organisms can mate and produce fertile offspring, they are probably members of the same species.

A few thoughts about life over the long term. . .

Supernovas can occur approx 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...