Are there genetically controlled habitat-specific differences in spatial aggregation of drosophilids?
Tóm tắt
Variation in spatial patterns of competing organisms is of fundamental importance for community and population processes. Yet the mechanisms controlling subjects like the degree of spatial aggregation in competing insect larvae across fragmented resources have rarely been addressed. In the present study, we tested for systematic differences in the spatial distribution patterns of Drosophila subobscura in natural fly communities, and found significant differences in two habitats that differ in the availability of breeding substrate types (decaying fruits). Assuming that the spatial egg-laying behaviour of drosophilids is under genetic control, and that different breeding substrates mediate different density-dependent larval fitness consequences, we tested whether adaptive genotypic variability is involved in the local variation of egg distribution patterns. We extracted isofemale lines from both habitats and analysed the spatial distribution of eggs achieved by single female flies under controlled laboratory conditions. This is a reasonable first test, because spatial patterns at the fly population level can be attributed to individual egg-laying behaviour. The degree of individual egg aggregation significantly depended on fly line identity, which indicates the existence of behavioural variants in natural populations. Based on habitat-dependent differences in the degree of spatial aggregation, we discuss to what extent our findings may reflect a behavioural adaptation to local breeding conditions.
Tài liệu tham khảo
Begon ME, Harper JL, Townsend CR (1996) Ecology—individuals, populations and communities. Blackwell, Oxford
Courtney SP, Kibota TT, Singleton TA (1990) Ecology of mushroom-feeding drosophilidae. Adv Ecol Res 20:225–274
del Solar E (1968) Selection for and against gregariousness in the choice of oviposition sites by Drosophila pseudoobscura. Genetics 58:275–282
Driessen G, Hemerik L (1991) Aggregative response of parasitoids and parasitism in populations of Drosophila breeding in fungi. Oikos 61:96–107
Gillespie JH, Turelli M (1989) Genotype-environment interactions and the maintenance of polygenic variation. Genetics 107:321–330
Godfray HCJ, Partridge L, Harvey PH (1991) Clutch size. Annu Rev Ecol Syst 22:409–429
Gu H, Dorn S (2000) Genetic variation in behavioral response to herbivore-infested plants in the parasitic wasp, Cotesia glomerata (L.) (Hymenoptera: Braconidae). J Insect Behav 13:141–156
Hartley S, Shorrocks B (2002) A general framework for the aggregation model of coexistence. J Anim Ecol 71:651–662
Heard SB (1998) Resource patch density and larval aggregation in mushroom-breeding flies. Oikos 81:187–195
Heard SB, Remer LC (1997) Clutch-size behavior and coexistence in ephemeral-patch competition models. Am Nat 150:744–770
Hoffmeister TS, Rohlfs M (2001) Aggregative egg distributions may promote species co-existence—but why do they exist? Evol Ecol Res 3:37–50
Ives AR (1988) Aggregation and coexistence of competitors. Ann Zool Fenn 25:75–88
Kimura M (1983) The neutral theory of molecular evolution. Cambridge University Press, Cambridge
Krimbas CB (1993) Drosophila subobscura—biology, genetics and inversion polymorphism. Dr Kovac, Hamburg
Kuno E (1991) Sampling and analysis of insect populations. Annu Rev Entomol 36:285–304
Lloyd M (1967) Mean crowding. J Anim Ecol 36:1–30
Manel S, Schwartz MK, Luikart G, Taberlet P (2003) Landscape genetics: combining landscape ecology and population genetics. Trends Ecol Evol 18:189–197
McKay JK, Latta RG (2002) Adaptive population divergence: markers, QTL and traits. Trends Ecol Evol 17:285–291
Messina FJ (1998) Maternal effects on larval competition in insects. In: Mousseau TA, Fox CW (eds) Maternal effects as adaptations. Oxford University Press, New York, pp 227–243
Rohlfs M (2003) Einen evolutionsökologische Analyse des Aggregations-Koexistenz-Modells für Drosophila. Dissertation thesis. Christian-Albrechts-University of Kiel. http://e-diss.uni-kiel.de/diss_719/d719.pdf
Rohlfs M, Hoffmeister TS (2003) An evolutionary explanation of the aggregation model of species coexistence. Proc R Soc Lond B (suppl) 270:S33–S35
Rohlfs M, Hoffmeister TS (2004) Spatial aggregation across ephemeral resource patches in insect communities: an adaptive response to natural enemies? Oecologia 140:654–661
Ruiz-Dubreuil G, del Solar E (1986) Effect of selection on oviposition site preference in Drosophila melanogaster. Aust J Biol Sci 39:155–160
Ruiz-Dubreuil G, Burnet B, Connolly K (1994) Behavioural correlates of selection for oviposition by Drosophila melanogaster females in a patchy environment. Heredity 73:103–110
Sevenster JG (1996) Aggregation and coexistence. I. Theory and analysis. J Anim Ecol 65:297–307
Shorrocks B, Rosewell J, Edwards K, Atkinson W (1984) Interspecific competition is not a major organizing force in many insect communities. Nature 310:310–312
Shorrocks B, Sevenster JG (1995) Explaining local species diversity. Proc R Soc Lond B Biol Sci 260:305–309
Southwood TRE (1978) Ecological methods. Chapman and Hall, London
van Tienderen PH, de Haan AA, van der Linden CG, Vosman B (2002) Biodiversity assessment using markers for ecologically important traits. Trends Ecol Evol 17:577–582
Tilman D, Kareiva P (eds) (1997) Spatial ecology—the role of space in population dynamics and interspecific interactions. Princeton University Press, Princeton
Toda M, Kimura M, Tuno N (1999) Coexistence mechanisms of mycophagous drosophilids on multispecies fungal hosts: aggregation and resource partitioning. J Anim Ecol 68:794–803
Vet LEM (2001) Parasitoid searching efficiency links behaviour to population processes. Appl Entomol Zool 36:399–408
Wajnberg E, Rosi MC, Colazza S (1999) Genetic variation in patch time allocation in a parasitic wasp. J Anim Ecol 68:121–133
Wertheim B (2001) Ecology of Drosophila aggregation pheromone: a multitrophic approach. PhD thesis, Wageningen Agricultural University, Netherlands
Wertheim B, Sevenster JG, Eijs IEM, van Alphen JJM (2000) Species diversity in mycophagous insect communities: the case of spatial aggregation vs. resource partitioning. J Anim Ecol 69:335–351
Wertheim B, Marchais J, Vet LEM, Dicke M (2002) Allee effects in larval resource exploitation in Drosophila: an interaction between density of adults, larvae and micro-organisms. Ecol Entomol 27:608–617
Wilson K, Lessells CM (1994) Evolution of clutch size in insects. I. A review of static optimality models. J Evol Biol 7:339–363
Woodcock BA, Watt AD, Leather SR (2002) Aggregation, habitat quality and coexistence: a case study on carrion fly communities in slug cadavers. J Anim Ecol 71:131–140