Dynamic landscapes driving diversity T. Janzen, R.S. Etienne Community and Conservation Ecology Group University of Groningen Picture courtesy Jen Reynolds
Dynamic landscapes & diversity Diversity mainly driven by speciation – Sympatric speciation – Allopatric speciation Slow changes in landscape – Mountain ridges – Formation of lakes – Drifting of continents
Dynamic landscapes Fast (repetitive) changes in landscape: – Glaciation – Islands and changing sea levels – Fluctuating lake levels – On a different spatio-temporal scale: Predators Dispersal and expansion Alternating periods of allopatry and sympatry Aguilée et al. 2010
Aguilée et al 2010
Focal system
Lake Tanganyika Million years ago Water elvel below present
Eretmodini Ruber et al PNAS
Summary and aims Changes in landscapes can be relatively fast Lake Tanganyika has experienced dramatic changes in water level Have these changes in waterlevel driven the current diversity in cichlids?
The model
| 10 Lineages-through-time plots (LTT) Slide by R. S. Etienne
Lamprologini Sturmbauer et al. 2010
Typical run Simulation Empirical data Water level
Stochasticity
Extinction rate Speciation rate Rate of water level fluctuation
Found estimates ModelEmpirical Speciation events / MY 0.87± Extinction events / MY 5.00E-06NA Average time to Water level change 100ky±30k61ky±13k Spec rate: Coyne & Orr 2004 Waterlevel: Lezzar 1996, Cohen 1997, Scholz 2003
Conclusion & Perspectives Dynamic landscapes are important in shaping diversity Estimates of this model are well in line with empirical estimates Fit this model to similar systems
Thanks to: Rampal Etienne Lucas Molleman Hanno Hildenbrandt Stephan Koblmüller Picture courtesy T. Janzen