Changing habitats, changing populations?

1. Changing habitats,changing populations? Life-history evolution of coexisting Drosophila species in a heterogeneous environment. Kim van der Linde , Institute for Evolutionary and Ecological Sciences, Section Animal Ecology and Section Evolutionary Biology, Leiden University, The Netherlands.

2. Changing habitats, changing populations? • Darwin finches (Grant & Grant) Beaksize variation between generations is correlated with size of available seed. • Guppies (??) Life-history strategies vary with predator. Transplantation to other stream with other predator induces evolution to the other strategy. • ??? Add self more examples! Changing habitats, changing populations?

3. A life history trade off and community structure in a variable environment. Sevenster JG & van Alphen JJM (1993) J. Anim. Ecol. 62: 720-736. The environment is variable through the year. Species differ in life-history. A short development time is an advantage when fruit is abundant. A long survival time under food stress is an advantage when fruit is scares. A physical trade-off between development time and starvation resistance make that different species have a competitive advantage during different times of the year! Changing habitats, changing populations?

4. Changing habitats • Changes in: • vegetation structure • fruit availability • temperature • humidity • …. Changing habitats, changing populations?

5. Which traits? • Ecological important traits: • Development time • Starvation resistance • Life-history model of Sevenster & van Alphen (1993) • Body size • Egg size (Relative egg size) • Extension to the model by Toda & Kimura (1996) Changing habitats, changing populations?

6. Different habitats • Habitats differ in year round breeding substrate availability. • Local populations are likely to adapt to those differences. • Expected result is that populations from different habitats from the same species will show differences in the life-history traits. Changing habitats, changing populations?

7. Philippines 1994 • Collecting flies from four habitats: secondary forest, forest edge, kaingin and grassland. • Bring them to a common environment of the lab. • Measuring development time and starvation resistance. Changing habitats, changing populations?

8. Development times Changing habitats, changing populations?

9. Starvation resistances Changing habitats, changing populations?

10. Conclusions and questions • Habitat related variation between populations in development time. • Variation is of same pattern for all (7) species of the Sophophora subgenus. • But what are the realized values in the field? • Are some or all traits genetically correlated? Changing habitats, changing populations?

11. Common environment versus real environment Changing habitats, changing populations?

12. Genetic correlation's in D. melanogaster Development time + + 0 0 Body size 0 ± Longevity + Starvaton resistance / fat content Source: Zwaan, BJ (1993) Genetical and environmental aspects of aging in Drosophila melanogaster. Ph.D. thesis, Groningen Changing habitats, changing populations?

13. Questions after that • Does natural selection shape the life-history traits even throughout the year? • E.g. are there differences within flies collected in different times of the year? Changing habitats, changing populations?

14. Panama 1998 1 Expression of life-history traits in the original habitat 2 Transplantation experiment, offspring of many females 3 Transplantation experiment, offspring of a single female Changing habitats, changing populations?

15. Experiment 1 Transect 1 Transect 2 Hab. C Hab. A Hab. B Hab. A Hab. B Hab. C All stocks All stocks All stocks All stocks All stocks All stocks Transect 1 Transect 2 Hab. C Hab. A Hab. B Hab. A Hab. B Hab. C Changing habitats, changing populations?

16. Experiment 2 Transect 1 Hab. C Transect 2 Hab. A Hab. B Hab. A Hab. B Hab. C Hab. A of transect 1 Species 1 of Hab. A Species 2 of Hab. A Species 3.. of Hab. A Replica 1 Replica 1 Replica 2 Replica 2 Replica 3 Replica 3 Species 1 of Hab. B Species 2 of Hab. B Species .. of Hab. B Replica 1 Replica 1 Replica 2 Replica 2 Replica 3 Replica 3 Changing habitats, changing populations?

17. Experiment 3 Transect 1 Transect 1 Hab. C Transect 2 Hab. A Hab. A Hab. A Hab. B Hab. B Hab. B Hab. C Hab. A Species 1 of Hab. A Species 2 of Hab. A Species 3 of Hab. A Species 1 of Hab. A Species 2 of Hab. A Species 3 of Hab. A Species 1 of Hab. A Species 2 of Hab. A Species 3 of Hab. A Species 1 of Hab. A Species 2 of Hab. A Species 3 of Hab. A Replica 1 Species 1 of Hab. A Replica 1 Species 2 of Hab. A Replica 1 Species 3 of Hab. A Replica 1 Replica 1 Replica 1 Replica 2 Replica 2 Replica 2 Replica 1 Replica 1 Replica 1 Replica 2 Replica 2 Replica 2 Replica 3 Replica 1 Replica 3 Replica 1 Replica 3 Replica 1 Replica 2 Replica 2 Replica 2 Replica 3 Replica 1 Replica 3 Replica 1 Replica 3 Replica 1 Replica 2 Replica 2 Replica 2 Replica 3 Replica 3 Replica 3 Replica 2 Replica 2 Replica 2 Replica 3 Replica 3 Replica 3 Replica 3 Replica 3 Replica 3 Species 1 of Hab. B Species 2 of Hab. B Species 3 of Hab. B Species 1 of Hab. B Species 2 of Hab. B Species 3 of Hab. B Species 1 of Hab. B Species 2 of Hab. B Species 3 of Hab. B Species 1 of Hab. B Species 2 of Hab. B Species 3 of Hab. B Replica 1 Species 1 of Hab. B Replica 1 Species 2 of Hab. B Replica 1 Species 3 of Hab. B Replica 1 Replica 1 Replica 1 Replica 2 Replica 2 Replica 2 Replica 1 Replica 1 Replica 1 Replica 2 Replica 2 Replica 2 Replica 3 Replica 1 Replica 3 Replica 1 Replica 3 Replica 1 Replica 2 Replica 2 Replica 2 Replica 3 Replica 1 Replica 3 Replica 1 Replica 3 Replica 1 Replica 2 Replica 2 Replica 2 Replica 3 Replica 3 Replica 3 Replica 2 Replica 2 Replica 2 Replica 3 Replica 3 Replica 3 Replica 3 Replica 3 Replica 3 Changing habitats, changing populations?

18. Experiment 2& 3 Transect 1 Transect 2 Stocks Hab. C Hab. A Hab. B Hab. A Hab. B Hab. C Transect 1 Transect 3 Hab. C Hab. A Hab. B Hab. A Hab. B Hab. C Expe- riment Changing habitats, changing populations?