10.G BIO, C1 Patterns of Evolution (PART G)

Microevolution

Allele frequencies diverge within a species occurs over years or decades due to mutations, genetic drift, gene flow and natural selection. Evidence comes from analyzing organisms and populations

Macroevolution (Description)

Large scale changes in allele frequencies within a species that results in the formation of a new species. Typically occurs over thousands or millions of years due to geographic and reproductive isolation.

Macroevolution (Examples)

Examples include:

- Extinction

- Adaptive Radiation

- Evolution

- Coevolution

- Punctuated Equilibrium

- Changes in Genes

Extinction

A term that typically describes a species that no longer has any known living individuals.

Adaptive radiation

The process by which many related species evolve from a single ancestral species. This is also referred to as divergent evolution.

Divergent evolution

The process by which many related species evolve from a single ancestral species. Also referred to as adaptive radiation.

Convergent evolution

The process by which unrelated organisms come to resemble one another due to being subjected to similar selective pressures that result in similar adaptations (e.g. shark/dolphin; bat/bird)

Coevolution

The process by which two species evolve in response to changes in each other over time (e.g. flowers and insects)

Hypotheses on Rate of Evolution

Gradualism

Punctuated Equilibrium

Gradualism

Idea that species originate through a gradual change of adaptations

Punctuated equilibrium

Idea that speciation occurs relatively quickly in rapid bursts (due to environmental change) with long periods of genetic equilibrium in between