Lecture #24 

taxonomy 

binomial system 

both words are always in Latin and
are printed in italics or underlined 

Genus species 

Felis domestica  

Carl Linnaeus (1707-1778)

Linnaean System 

systematics 

Kingdom
Phylum  (plural: phyla)
Class
Order
Family
Genus (plural: genera)
Species (plural: species) 

Mechanisms of Species

Formation:
1. Isolation
2. Hybridization

1. Isolation
reproductive barrier
geographic or physical
genetic isolation

ecological isolation
   different habitats
   different activity patterns
         nocturnal
         diurnal
         crepuscular 

2. hybridization
     fertile hybrids
     nondisjunction    

     polyploidy

About half of all plant species are polyploid.

potato (Solanum)  N = 12

24, 36, 48, 60, 72, 96,
108, 120, 144

Spartina alterniflora    70
Spartina stricta    56
N = 7
Townsend’s Grass
Spartina townsendii    126 

the harem effect 

Origin of Life 

CH₄  methane
NH₃  ammonia
H₂O  water
H₂     hydrogen
H₂S   hydrogen sulfide 

Sources of Energy:
1. cosmic radiation
2. ultraviolet light
3. electrical discharge
4. heat
5. shock waves 

Miller and Urey 

Primal Soup Theory 

Linkage of monomers to form polymers probably
occurred on the surface of rocks and on clay
particles. 

aggregates 

colloids 

membranes 

enzymes 

nucleic acids 

autotrophic organisms 

heterotrophic organisms 

A. T. Oparin “The Origin of Life” 1938 

4 billion years ago