The Origin of Species

1
The Origin of Species
2
Species

• Biological Species

3
Ring Species
4
Barriers

• Prezygotic
• Habitat Isolation
• Behavior Isolation
• Temporal Isolation
• Mechanical Isolation
• Gametic Isolation

• Postzygotic
• Hybrid Sterility
• Hybrid Inviability
• Hybrid Breakdown

5
Habitat Isolation
6
Behavior Isolation
7
Behavior Isolation
8
Temporal Isolation
9
Mechanical Isolation
10
Gametic Isolation
11
Hybrid Sterility
12
Hybrid Inviability
13
Hybrid Breakdown
14
Modes of Speciation
15
Allopatric Speciation
16
Adaptive Radiation
17
Sympatric Speciation

• Autopolyploidy

18
Sympatric Speciation

• Allopolyploidy

19
Macroevolution
20
Gradualism

• Also called Neodarwinism
• Small changes over time
• Supporter Ernst Mayr

21
Punctuated Equilibrium

• Supporters Niles Eldredge Stephen J. Gould
• Speciation occurs in episodic events large
  periods of time with little change and short
  periods of time with large changes

22
Origin of Evolutionary Novelty

• Most novelties are modified versions of older
  structures
• preadaptation

23
Evo-devo

• Evolutionary Biology and Developmental Biology
  working together

24
Homeotic Genes

• Hox Genes- position information

25
Evolutionary Trends

• Evolutionary trends are not goal oriented

26
Adaptive Radiation

• The emergence of numerous species from a common
  ancestor introduced into an environment,
  presenting a diversity of new opportunities and
  problems