1. Paradox of the Cichlids outline of my PhD project Thijs Janzen Supervisor: Rampal Etienne Picture courtesy Jen Reynolds

2. Cichlids

3. The success of the cichlids Pharyngeal jaw Mouthbrooding Barlow 2000

4. Oliver 2010

5. The African Rift Lakes

6. Differences between the lakes Lake Victoria Lake Malawi Lake Tanganyika Age (My)0.25-0.753 – 59 – 12 # Species~700 ~250 Area (km 2 )68 63529 60032 893 Depth83 m706 m1 471 m

7. Lake VictoriaLake TanganyikaLake Malawi

8. Why should there be more? Age Water level Bathymetry

9. Waterlevel Water level changes frequently –King Mwangonde (1820) Owen 1990, Barlow 2000, Salzburger 2002

10. Why should there be more? Age Water level Bathymetry

11. TanganyikaMalawi Talling 1969, Scholz et al. 2007 Victoria

12. Water level Water level: 0 m

13. Water level Water level: -100 m

14. Water level Water level: -250 m

15. Water level -300 m Water level: -300 m

16. Water level Water level: -400 m

17. Water level Water level: -600 m

18. Water level Water level: -1000 m

19. Effects of water level changes Decrease in lake size Splitting in proto lakes Merging of sub-populations after water level rise

20. Summary of possible causes Age Water level Bathymetry

21. Research Questions What external factors determine the differences in biodiversity between the African Rift Lakes? How does biogeography influence biodiversity?

22. Approach Standard neutral model –Influence of environment size –Spatiality –Environmental change –Cyclic environment change –Splitting and merging of communities –Repeated splitting and merging

23. Approach Tailored model Check predictions with a tailored version –Correct size of lakes –Include explicit bathymetry –Remodel water level changes

24. The end Questions? Suggestions?

26. Conformism

27. Local variability

28. Picture courtesy Jen Reynolds

30. Other stuff to do Time-scale difference between speciation and environmental change Interaction between tectonic drift and biodiversity