2. Patterns of Evolution
There are several broad patterns of evolution observable in nature:
Speciation
Extinction
Gradualism
Punctuated equilibrium
Adaptive radiation (or Divergent evolution)
Convergent evolution
Coevolution

3. Speciation
Speciation - forming of a new species by evolution from pre-existing species.
Gene pools gradually become different & are no longer able to reproduce.
Some sort of isolation must occur
At this point the 2 groups are different species.
Pause and Play: Crash Course YouTube video on speciation:
Note: This video is a part of the Lab Station Activity after Concept 3 Notes

4. Extinction Extinction - elimination of a species.
Gradual extinction - occurs at a slow rate.
Ex: changes in climate, natural disasters.
Mass extinction - occurs when a catastrophic event changes the environment suddenly
Ex: massive volcano, meteor

5. Gradualism Slow changes over a long period of time
Example: The gradual evolution of peppered moths to become darker and darker over time due to the industrial revolution and the darkening of tree bark due to ashes

6. Punctuated equilibrium
Bursts of change followed by periods of stability
Example: Long periods of stability in the mammal population interrupted by bursts of change due to major environmental changes

7. Adaptive Radiation aka, Divergent Evolution
A number of different species arise from one common ancestor.
New environments caused them to evolve to be different
Leads to homologous structures
Similar structure, different use

8. Convergent Evolution
When unrelated species evolve similar characteristics because they live in similar environments
Leads to analogous structures
Different structure, same use

9. Coevolution
Two organisms change in response to each other forming a specialized relationship.

10. Sexual vs. Asexual Reproduction
Sexual Reproduction: takes two organisms to make offspring; process of meiosis to create gametes
Genetic changes  transcription/translation of different proteins  change in phenotype of an individual organism
Makes organisms better suited for changing environments
Asexual Reproduction: process of binary fission or mitosis where only one parent produces genetically identical offspring
Genetic variation can only occur through mutations of DNA
Better suited for stable environments