Speciation Modes: Pattern

1
Speciation Modes Pattern Process
Non-adaptive speciation
Adaptive speciation
Process
Geographic isolation, Isolation by
distance, Peripheral isolates
Allopatric speciation
Consumer-mediatedevolutionary branching
(Parapatric Speciation)
Pattern
Host race formation, Evolutionary branchingby
natural or sexual selection
Sympatric speciation
Chromosomalrearrangements
2
Three Key Characteristics

• Spatial differentiation
• Can either drive or be driven by the speciation
  process.
• Ecological differentiation
• Yields the only speciation criterion in
  asexuals.
• Reproductive differentiation
• Needs to evolve for speciation in sexuals.
• These characteristics can arise simultaneously or
  sequentially, and occur gradually or in
  externally determined phases

3
Speciation Cubes
Non-adaptive process
Adaptive process
Reproductive differentiation
Spatial differentiation
Ecological differentiation