1. Geography of Speciation Allopatric – Peripatric Parapatric Sympatric

2. Fig. 24-6 A. harrisi A. leucurus Sister species in allopatry

4. Peripatric Speciation (like allopatric, but offers drift a bigger role) Divergent natural selection &/or Genetic Drift = Speciation Divergent natural selection &/or Genetic Drift = Speciation

5. Sympatric and Parapatric Speciation What do we mean by sympatry or parapatry? – In same geographic area (or side-by-side)? – Exchanging gene flow during the speciation process? – How finely should we divide the environment? – Habitat isolation in the same geographic area = real sympatry?

6. Apple maggot fly Sympatric or Micro-allopatric? http://evolution.berkeley.edu/evosite/evo101/VC1eSympatric.sht ml Pre-mating RIM = host fidelity Post-mating RIM =  scent tracking in F1’s

7. Parapatric Speciation (sympatric, micro-allopatric?) Anthoxanthum odoratum Mine from mid-1800’s Contamination prevents most plant growth Strong, disruptive selection against interbreeding Different flowering times

8. Mine soils (black): Flowering is earlier (flowers more developed in a point sample) Antonovics, Heredity (2006) 97, 33–37. doi:10.1038/sj.hdy.6800835

9. Flowering stage along a transect from mine  field (border = dashed line) Common garden experiment included Trend persists over 40 years 40% less mating between forms

10. Parapatry, sympatry, or micro-allopatry?

11. Mechanisms of Speciation Mutation Drift Ecological Speciation (Driven by natural selection) Sexual Selection

12. Allopatric Speciation--Mutation http://evolution.berkeley.edu/evosite/history/modsynth2.shtml

13. Gene Duplication is common LOF mutation is common Fixation of alternate mutations can  hybrid inviability