1. The Origin of Life & Evolution

2. The Origin of Life
Heterotroph Hypothesis: 1st organisms were heterotrophs
Conditions
Raw materials: H2, NH3, CH4, H2O
Temperature: VERY HOT!
Other energy sources: Lightening, solar radiation, volcanos

3. http://science. discovery

4. Origin of Life: Results of Experiment
Synthesis Reaction!
“Build” aggregates (clumps) of simple sugars & amino acids
Amino acids building blocks for proteins!
“Reproduction”- amino acids split
Lead to simple single celled organisms

5. Origin of Life: Cont’d Anaerobic respiration
Energy + CO2 + H2O released
Autotrophs  use CO2 & H2O  release O2
Aerobic Respiration  Use O2 & glucose  release CO2

6. Evolution Evolution- process of change over time
Theory of organic evolution
Compare existing to previous forms of life

7. Homologous Structures
Age of Earth
Recent Fossil Finds
Biogeography
Evidence for Evolution
Pgs
Homologous Molecules
Embryology
Life’s Common Genetic
Code

9. The History of Evolution: LaMark
LaMark (1802)- “Changes occur in species for their improvement”
Develop traits due to a need for them
Example: Giraffes grow tall necks because they need to reach leaves at the tops of trees
Transmission of acquired characteristic
If a trait is acquired, it will be passed on
Evolution
Add up all characteristics, there is overall change

10. The History of Evolution: Weismann
Traits develop NOT based on need
Acquired traits cannot be passed on

11. The History of Evolution: Darwin
Adaptations: Traits that enable an organism to survive within a specific niche
Natural selection
Survival of fittest
The driving force behind evolution
Transmission of favorable characteristics
Pass on adaptations to next generation
Variation in species (adaptations)
Competition &
Environmental Conditions
Natural
Selection
Don’t survive
Survive!
Pass on traits to
next generation
Traits not passed on
Overall change in species:
EVOLUTION

12. The History of Evolution: DeVries
DeVries (1886): “Variation is the result of mutation”
Results from:
Random mutation
Sexual reproduction
Meiosis/Gamete formation
Different DNA!

13. Modern Theory of Evolution
Sources of variation
Random mutation
Sexual reproduction
Meiosis/gamete formation
Differing DNA transferred to next generation
Natural selection
Survival of the fittest
Influences how quickly species adapt

14. Modern Theory of Evolution: Cont’d
Rate of Evolution Relies on Environment
Unchanging/Stable Environment
Favored traits  passed on
Unfavored traits  not passed on
Slow adaptation
Changing/Unstable Environment
High turnover for survival of fittest
Must continue to adapt to changing environment
Limited resources

15. Changes in Species Gradualism
Slow, constant change in species over time

16. Changes in Species Punctuated Equilibrium
Long periods of time with little change in environment with short bursts with great change in species

17. Cladogram Determine similarities by comparing DNA sequences (gel
electrophoresis)