Evolution-
I. Biogenesis / Spontaneous Generation
a. Redi
b. Pasteur
II. Origin of Life
a. Earth- 4.5 billion yrs old
b. First Life 3.5-4 billion years ago
c. Oparin's Hypothesis- early atmosphere- water, methane, nitrogen, hydrogen
energy caused these to rearrange into simple organic molecules
from there- simple cells
d. first prokaryotes-1) heterotrophic anaerobes
2) heterotrophic and autotrophic (chemosynthesis) anaerobes
3) heterotrophic and photosynthetic anaerobes
4) heterotrophic and photosynthetic aerobes
e. first eukaryotes- endosymbiosis - 1.5-2 billion years ago
f. significance of Ps- oxygen- aerobic resp (more energy available)
ozone layer (allowed life on land)
g. Note- aerobic resp first evolved as a way to make oxygen harmless
III. Evolution- the theory that species change over time
A) Evidence- 1) fossils- sedimentary rock
2) Biochemical similarity- Genetic code, ATP
3) Structural similarity- homologous structures
4) DNA analysis
B) Theories of Evolution-
1) Lamarck- Importance of environment / Inheritance of acquired traits
2) Charles Darwin- sailed on the HMS Beagle
a) Natural Selection (Survival of the Fittest)
natural variety among organisms
not all can survive
those best suited to the environment survive and pass on the DNA for these
adaptations (inherited trait that helps survival)
C) 4 Major Eras in the evolution of life on earth
a) Pre cambrian-beginning of life to .5 billion yrs ago- mostly unicellular life
b) palezoic- .5 bill to .250 mill yrs ago inverts/fish/amphibs/reptiles/most plants
c) mesozoic 250 miil to 67 mill yrs ago- dinosaurs, birds, primnitive mammals
d) cenozoi- 67 mill yrs ago to present - modern mammals
IV. Patterns of Evolution
A) Co-evoluion - predator /prey
B) Convergent evolution shark and dolphin
C) divergent evolution- clam and octopus
D) Artificial selection- breeding
V. Factors that affect evolution- affect either the DNA or the environment or ability to reproduce
A) Mutation
B) Migration
C) Environmental changes- flood, drought, ice age etc.
D) Isolation
VI. Examples of Natural selection- the environment changes
1) directional selection- anteaters/tongue length
2) stabilizing selection - small lizards (slow) large lizards (easily seen)
3) disruptive selection - limpets color variation
VII. Gradualism vs Punctuated equilibrium
VII. Human evolution
A) Early Primates- fingers, stereo vision
B) Some evolved further- - opposable thumb, large brain compared to body size, These are monkey, apes etc.
C) Some evolved even further- Hominids: Bipeds and large frontal part of the brain
Hominids are humans and our caveman ancestors- we are the only living hominid