Microevolution and Macroevolution

• 1. Mutation- addtion of new alleles to a population through changes in DNA
• 2. Immigration- introduction of new allele or additional copies of existing alleles via members of different populations
• 3. Genetic Drift- changes in frequency of alleles in a population due to random effects
• 4. Selection- changed in frequency of alleles in a population due to differential survival and reproductive sucess of individuals carrying specific alleles

Element that has a great inifinity to to bind to iron, usually comes from surface of extraterrestial sources- indicating major impact event

• 5 major mass extinctions have played a significatn role in shaping modern diversity
• ex. KT extinction

• Bolide impact events
• Flood Basal Eruptions- Volcanism
• Eustatic sea-level changes- changing sea level due to Plate tectonics and climate change <-- buggest mechanism for evolution

Comparision of clade diversification can reveal major events in the history of life

• representatives from 3 statistically distinct "Faunal Cohorts" showing patterns of diversification:
• 1. Vendian-Cambrian Fauna
• 2. Cambrian-Palaeozoic Fauna
• 3. Mesozoic-Cenozoic Fauna

• Orgin and extinction of clades can be modeled as a random process
• repeates many times before the "gambler losses"--> total extinction

Patterns of orgin, diversification & extinction of clades can reveal major events in the history of life

• arises through unique, large-scale phenomena
• contingent historical events are important-especially random
• e.g. KT extinction

Accummulated effects of microevolution over very long periods of time

• no unique phenomena
• extinction
• evolution is continous adaptations
• e.g. horse

Broad scale patterns of change above species level over geological time. Historical contingency determines which lineages persist.

• Cladogenesis(speciation) is the main creative process
• Extinction (lineage sorting) is the main destructive process

Genetic changed within a population level over ecological time scales; selection determines which traits persist.

• Mutation is the main creative process
• Selection is the main destructive process