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.

10 dec 1998Changing habitats, changing populations? 2 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!

10 dec 1998Changing 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: 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!

10 dec 1998Changing habitats, changing populations? 4 Changing habitats Changes in: –vegetation structure –fruit availability –temperature –humidity –….

10 dec 1998Changing 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)

10 dec 1998Changing 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.

10 dec 1998Changing 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.

10 dec 1998Changing habitats, changing populations? 8 Development times

10 dec 1998Changing habitats, changing populations? 9 Starvation resistances

10 dec 1998Changing 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?

10 dec 1998Changing habitats, changing populations? 11 Common environment versus real environment

10 dec 1998Changing habitats, changing populations? 12 Genetic correlation's in D. melanogaster Development time Body size Longevity Starvaton resistance / fat content ±0 Source: Zwaan, BJ (1993) Genetical and environmental aspects of aging in Drosophila melanogaster. Ph.D. thesis, Groningen

10 dec 1998Changing 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?

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

10 dec 1998Changing habitats, changing populations? 15 Transect 1Transect 2 Transect 1Transect 2 Hab. AHab. B Hab. C Hab. AHab. BHab. C Experiment 1 Hab. AHab. B Hab. C Hab. AHab. BHab. C All stocks All stocks All stocks All stocks All stocks All stocks

10 dec 1998Changing habitats, changing populations? 16 Transect 1 Transect 2 Hab. AHab. B Hab. A of transect 1 Species 1 of Hab. A Replica 1 Replica 2 Replica 3 Species 2 of Hab. A Replica 3 Replica 2 Replica 1 Species 1 of Hab. B Replica 1 Replica 2 Replica 3 Species 2 of Hab. B Replica 3 Replica 2 Replica 1 Species.. of Hab. B Species 3.. of Hab. A Hab. A Hab. B Experiment 2 Hab. C

10 dec 1998Changing habitats, changing populations? 17 Transect 1 Hab. AHab. B Hab. A Species 1 of Hab. B Replica 1 Replica 2 Replica 3 Species 2 of Hab. B Replica 3 Replica 2 Replica 1 Experiment 3 Species 3 of Hab. B Replica 3 Replica 2 Replica 1 Species 1 of Hab. B Replica 1 Replica 2 Replica 3 Species 2 of Hab. B Replica 3 Replica 2 Replica 1 Species 3 of Hab. B Replica 3 Replica 2 Replica 1 Species 1 of Hab. B Replica 1 Replica 2 Replica 3 Species 2 of Hab. B Replica 3 Replica 2 Replica 1 Species 3 of Hab. B Replica 3 Replica 2 Replica 1 Species 1 of Hab. B Replica 1 Replica 2 Replica 3 Species 2 of Hab. B Replica 3 Replica 2 Replica 1 Species 3 of Hab. B Replica 3 Replica 2 Replica 1 Species 1 of Hab. B Replica 1 Replica 2 Replica 3 Species 2 of Hab. B Replica 3 Replica 2 Replica 1 Species 3 of Hab. B Replica 3 Replica 2 Replica 1 Species 1 of Hab. A Replica 1 Replica 2 Replica 3 Species 2 of Hab. A Replica 3 Replica 2 Replica 1 Species 3 of Hab. A Replica 3 Replica 2 Replica 1 Species 1 of Hab. A Replica 1 Replica 2 Replica 3 Species 2 of Hab. A Replica 3 Replica 2 Replica 1 Species 3 of Hab. A Replica 3 Replica 2 Replica 1 Species 1 of Hab. A Replica 1 Replica 2 Replica 3 Species 2 of Hab. A Replica 3 Replica 2 Replica 1 Species 3 of Hab. A Replica 3 Replica 2 Replica 1 Species 1 of Hab. A Replica 1 Replica 2 Replica 3 Species 2 of Hab. A Replica 3 Replica 2 Replica 1 Species 3 of Hab. A Replica 3 Replica 2 Replica 1 Species 1 of Hab. A Replica 1 Replica 2 Replica 3 Species 2 of Hab. A Replica 3 Replica 2 Replica 1 Species 3 of Hab. A Replica 3 Replica 2 Replica 1 Transect 1 Hab. AHab. B Hab. C Transect 2 Hab. A Hab. B Hab. C

10 dec 1998Changing habitats, changing populations? 18 Transect 1Transect 3 Hab. AHab. B Hab. C Hab. AHab. BHab. C Transect 1Transect 2 Hab. AHab. B Hab. C Hab. AHab. BHab. C Experiment 2& 3 Stocks Expe- riment