1. Recall… Evolution is change over time Proof of evolution Fossils
Comparative anatomy
Embryology
Cytology
Biochemistry
The sequence of amino acids in the cytochrome c molecule, an enzyme found in mitochondria, is identical in humans and chimpanzees
fossils

2. Early Earth Composition: molten body  solid crust surface (hot)
Atmosphere – probably gases from volcanic eruptions
Oxygen-poor
Eventual cooling, formation of oceans  life on Earth (~3.5 billion yrs ago)

3. The Early Earth “soup”
Heterotrophic Hypothesis: organic chemistry may spontaneously form from inorganic chemistry
autotrophs developed after the evolution of heterotrophs partly because the primitive environment of the Earth lacked carbon dioxide
Miller-Urey Experiment

4. Origin of Life: Cells First cells: prokaryotic Small
Prokaryotes have no nucleus and no membrane bound organelles
First cells: prokaryotic
Small
Capable of living in extreme environments (like deep sea vents)
Then the appearance of photosynthesizing prokaryotes (cyanobacteria)
Production of oxygen  ozone layer  appearance of eukaryotes

5. Appearance of Eukaryotes
~1.8 billion years ago
Endosymbiont Theory: eukaryotic cell ancestors living in association with prokaryotic cells
Evidence for the endosymbiont theory
mtDNA & cpDNA, and its circular arrangement
Prokaryotic ribosomes
Mitochondria and chloroplast reproduction by fission
Eukaroytes have a nucleus and membrane bound organelles

6. Theories of Evolution Lamarck- use and disuse
When environments changed, organisms had to change their behavior to survive.
If they began to use an organ more than they had in the past, it would increase in its lifetime.
If a giraffe stretched its neck for leaves, for example, a "nervous fluid" would flow into its neck and make it longer.
Its offspring would inherit the longer neck, and continued stretching would make it longer still over several generations.
Meanwhile organs that organisms stopped using would shrink.

7. Darwin- natural selection
Finches
Peppered moth game
peppered moth simulation
Ant simulation

8. Natural Selection Conditions vital to this process are Overproduction
Finite resources
Genetic variation (mutation and sexual reproduction including crossing over)
Adaptive value
Selection by the environment of those better able to survive and reproduce
“survival of fittest”

9. Natural selection acting on phenotypes
Stabilizing selection: favors a mean, eliminates extremes (ex: birth weight)
Directional selection: favors one extreme (ex: peppered moth)
Disruptive selection: favors two extremes, eliminates the mean (ex: Northern water snakes color patterns)

10. Examples of Adaptation
Camouflage: Cuttlefish, Leafy Sea Dragon

11. Examples of Adaptation
Mimicry: evolving to resemble another species (drone fly, ash borer)

13. Gradualism vs. punctuated equilibrium
Gradualism: selection and variation that happens more gradually
Over a short period of time it is hard to notice
Punctuated equilibrium: change comes in spurts
There is a period of very little change, and then one or a few huge changes occur