Department of Botany and Zoology
Prof. Allan G. Ellis
I am an evolutionary ecologist studying the evolution of diversity and its ecological and evolutionary consequences. I am fortunate to work in an extraordinary evolutionary laboratory, the hyperdiverse Cape Floristic Region, where the products of the diversification process have accumulated into diverse and complex communities of interacting species. Ultimately I am interested in the mechanisms which 1) determine levels of specialisation of interactions within these communities and 2) drive divergence of interactions/phenotypes across populations within species (and ultimately give rise to new species). Of particular interest to me is the influence of the ever changing biotic environment on diversification. How do (new) species integrate into existing communities? How does their addition alter interaction structure of communities and ultimately selection on all community members? Does accumulation of diversity itself stimulate further diversification in a positive feedback loop?
My current research is primarily focused around the evolution of specialization and its consequences in the community context. I am addressing various aspects of this problem using interactions between plants and their pollinators (Gorteria-Megapalpus and Tritoniopsis-nemestrinid fly systems), insect herbivores (Restionaceae-Cephalelus leafhoppers), bacterial symbionts (Acacia-rhizobia) and edaphic environments (Aizoaceae-soils). In each of these systems I use a multi-tiered approach to elucidate mechanisms driving evolution of specialisation and its ecological and evolutionary consequences. I use solid natural history observations and molecular datasets to establish the patterns – phenotypic variation, interaction networks, evolutionary history – and to derive hypotheses about likely mechanisms. Field and greenhouse based experiments are then used to test these mechanistic hypotheses.
I am characterising the biotic landscape gradients that underly the radical diversification of floral form in the beetle daisy (Gorteria diffusa) and experimentally attempting to tease apart the roles of pollinator community composition, pollinator densities, antagonist densities and plant competition environments in driving floral trait evolution.
Also in the Gorteria diffusa system, we are examining the influence of selection imposed be effective pollinators, ineffective pollinators and floral antagonists (nectar and pollen thieves) on floral specialization.
We are exploring the complex selection gradients underlying floral tube length evolution in the irid, Tritoniopsis revoluta, which is pollinated by nemestrinid flies and Amegilla bees. (with Bruce Anderson)
It has frequently been argued that Cape plants are strongly pollen limited and this promotes diversification. We are assembling available datasets to test whether this is in fact the case.
The existence and function of non-pigment based structural colours have long been known from animals, but have only very recently been investigated in plants. We are surveying Cape flowers for structural colour (iridescence and glossiness) and experimentally exploring floral iridescence and its functions in Spiloxene capensis. (with Heather Whitney)
We are studying variability of dispersal and dormancy traits across broad geographic areas for many daisy species to gain understanding of the influence of environmental predictability and reproductive traits (breeding system, pollination systems) on the evolution of dispersal in space and time. (with Bruce Anderson)
We are using the Restionaceae and their insect herbivores to take a first look at plant-insect diversity relationships, insect community (network) structure and the evolution of specialization in insect herbivores in the Cape. Insect ecology and evolution in the Cape is very poorly known in comparison to the plants. We don’t, for instance, know how the remarkable plant diversification in the Cape has influenced insect evolution. (with Bruce Anderson, Jaco Le Roux and Peter Linder)
We are characterizing legume-rhizobium interaction networks in the Cape and investigating the integration into and influence of invasive legumes on these underground mutualisms. (with Jaco le Roux)
We are examining the influence of plant size on diversification of the succulent Karoo flora, with a focus on experimentally assessing the influence of size on neutral and adaptive aspects of divergence. (with Tony Verboom)
“Evolutionary drivers of temporal and spatial host-use patterns in restio leafhoppers Cephalelus Percheron (Cicadellidae: Cephalelini)” (with B Anderson)
"The role of plant size in rates of diversification"
Contact me directly:firstname.lastname@example.org
48. De Waal C, B. Anderson & AG Ellis. 2015. Dispersal, dormancy and life history trade-offs at the individual-, population- and species-level in southern African Asteraceae. New Phytologist. Accepted.
47. Gildenhuys E, AG Ellis, SP Carroll & JJ Le Roux. 2015. From the Neotropics to the Namib: evidence for rapid ecological divergence following extreme long-distance dispersal. Botanical Journal of the Linnean Society. DOI: 10.1111/boj.12334
46. Pfaff MC, Branch GM, Fisher JL, Hoffman V, Ellis AG, JL Largier. 2015. Delivery of marine larvae to shore requires multiple sequential transport mechanisms. Ecology 96(5): 1399–1410.
45. De Waal C, B. Anderson & AG Ellis. 2015. Relative density and dispersion pattern of two southern African Asteraceae affect fecundity through heterospecific interference and mate availability, not pollinator visitation rate. Journal of Ecology 103: 513-525.
44. Gildenhuys E, AG Ellis, SP Carroll & JJ Le Roux. 2015. Combining natal range distributions and phylogeny to resolve biogeographic uncertainties in balloon vines (Cardiospermum, Sapindaceae). Diversity and Distributions 21 (2), 163-174. DOI: 10.1111/ddi.12261
43. Ellis AG, T van der Niet, SD Johnson, GA Verboom & HP Linder. 2014. Speciation and extinction in the Greater Cape Floristic Region. In: N Allsopp, JF Colville, GA verboom (Eds). Fynbos:Ecology, Evolution and Conservation of a Megadiverse Region. Oxford University Press. P119-141.
42. Anderson B, AG Ellis, J Rodger, A Pauw, J Midgley, N Allsopp & SD Johnson. 2014. Biotic interactions. In: N Allsopp, JF Colville, GA verboom (Eds). Fynbos:Ecology, Evolution and Conservation of a Megadiverse Region. Oxford University Press
41. Anderson B., P Ros, TJ Wiese & AG Ellis. 2014. Intraspecific divergence and convergence of floral tube length in specialized pollination interactions. Proc. R. Soc. B 281, 20141420
40. De Waal C, JG Rodger, B Anderson & AG Ellis. 2014. Selfing ability and dispersal are positively related, but not affected by range position: a multispecies study on southern African Asteraceae. Journal of Evolutionary Biology 27: 250-259.
39. Mavengere NR, AG Ellis & JJ Le Roux. 2014. Burkholderia aspalathi sp. nov., isolated from root nodules of the South African legume Aspalathus abietina Thunb. International Journal of Systematic and Evolutionary Microbiology 64: 1906-1912.
38. Ellis AG, SF Brockington, ML de Jager, G Mellers, RH Walker & BJ Glover. 2014. Floral trait variation and integration as a function of sexual deception in Gorteria diffusa. Philosophical Transactions of the Royal Society B 369: 20130563
37. De Jager ML & AG Ellis. 2014. How the costs of deception affect learned resistance. Proc. Roy. Soc. B. 281: 20132861. http://dx.doi.org/10.1098/rspb.2013.2861
36. De Jager ML & AG Ellis. 2014. Floral polymorphism and the trade-offs of attracting pollinating and florivorous insects. Annals of Botany 113:213-222. doi:10.1093/aob/ mct189
35. Augustyn WJ, B Anderson, M Stiller & AG Ellis. 2013. Specialised host-use and phenophase tracking in restio leafhoppers, Cephalelus (Cicadellidae: Cephalelini) in the Cape Floristic Region. Journal of Insect Conservation 17 (6): 1267-1274.
34. Gildenhuys E, AG Ellis, SP Carroll & JJ Le Roux. 2013. The ecology, biogeography, history and future of two globally important weeds: Cardiospermum halicacabum Linn. and C. grandiflorum Sw. NeoBiota 19: 45–65. doi: 10.3897/neobiota.19.5279
33. Blignaut M, AG Ellis, JJ Le Roux. 2013. Towards a transferable and cost-effective plant AFLP protocol. PLoS One 8(4) : e61704
32. De Jager ML & AG Ellis. 2013. The influence of pollinator phylogeography and mate preference on floral divergence in a sexually deceptive daisy. Evolution 67: 1706–1714
31. Stangberg F, AG Ellis & AA Anderberg. 2013. Evolutionary relationships in Gorteria: a re-evaluation. TAXON 62(3) 537-549.
30. De Jager ML & AG Ellis. 2012. Gender specific preference for floral traits. Functional Ecology 26:1197-1204.
29. Ellis AG & SD Johnson. 2012. Lack of floral constancy by bee fly pollinators: implications for ethological isolation in an African daisy. Behavioral Ecology 23 (4), 729-734
28. Whitney HM, SA Rands. NJ Elton & AG Ellis. 2012. A technique for measuring petal gloss, with examples from the Namaqualand flora. Plos One: 7 (1): e29476
27. Ellis AG and B Anderson. 2011. Pollinator mediated floral divergence in the absence of pollinator shifts. In: Patiny S (Ed). Evolution of plant-pollinator relationships. Cambridge University Press. P237-262.
26. Ros P, AG Ellis & B Anderson. 2011. Maintenance of sympatric floral tube-length variation in a Cape irid. Biological Journal of the Linnean Society 104: 129-137.
25. De Jager ML, LL Dreyer & AG Ellis. 2011. Do pollinators influence the assembly of flower colours within plant communities? Oecologia. 166: 543-553.
24. Johnson SD, CI Peter, AG Ellis, E Boberg, C Botes; & T van der Niet. 2011. Diverse pollination systems of the twin-spurred orchid genus Satyrium in African grasslands. Plant Systematics and Evolution. 292: 95-103.
23. Ellis AG. 2011. Deserts as laboratories of evolution. South African Journal of Science 107: 9-10.
22. Whitney HM, Glower BJ, Walker R & AG Ellis 2011 The contribution of epidermal structure to flower colour in the South African flora. Curtis’s Botanical Magazine 28 (4): 349-371
21. Duncan G & AG Ellis 2011. 723 Gorteria diffusa. Curtis’s Botanical Magazine 28 (4): 341-348.
20. Duncan G & AG Ellis 2011. 716 Spiloxene capensis. Curtis’s Botanical Magazine 28 (4): 260-268.
19. Ellis AG & SD Johnson. 2010. Floral mimicry enhances pollen export: the evolution of pollination by sexual deceit outside of the Orchidaceae. American Naturalist. 176 (5): E143-E151.
18. Ellis AG & SD Johnson. 2010. Gender differences in the effects of floral spur length manipulation on fitness in a hermaphrodite orchid. International Journal of Plant Sciences 171(9): 1010-1019.
17. Anderson B, JS Terblanche & AG Ellis. 2010. Predictable patterns of trait mismatches between interacting plants and insects. BMC Evolutionary Biology 10:204.
16. Thomas MM, BJ Glover, AG Ellis, V. Savolainen and PJ Rudall. 2009. Development of a complex floral trait: The pollinator-attracting petal spots of the beetle daisy, Gorteria diffusa (Asteraceae). American Journal of Botany 96(12): 2184-2196.
15. de Merxem DG, B Borremans, ML de Jager, T Johnson, M Jooste, P Ros, RD Zenni, AG Ellis & B Anderson. 2009. The importance of flower visitors not predicted by floral syndromes. South African Journal of Botany 75: 660-667.
14. Ellis AG & SD Johnson. 2009. The evolution of floral variation without pollinator shifts in Gorteria diffusa (Asteraceae). American Journal of Botany 96(4): 793-801.
13. Dumri K, L Seipold, J Schmidt, G Gerlach, S Dötterl, AG Ellis & LA Wessjohann. 2008. Non-volatile floral oils of Diascia spp. (Scrophulariaceae). Phytochemistry 69: 1372-1383.
12. Ellis AG, AE Weis & B Gaut. 2007. The spatial scale of local adaptation and population genetic structure in a miniature succulent, Argyroderma pearsonii. New Phytologist 174 (4): 904-914.
11. Johnson SD, AG Ellis & S Dotterl. 2007. Specialization for pollination by beetles and wasps: the role of lollipop hairs and fragrance in Satyrium microrrhynchum (Orchidaceae). American Journal of Botany 94 (1): 47-55.
10. Ellis AG, AE Weis & B Gaut. 2006. Evolutionary radiation of “stone plants” in the genus Argyroderma: unravelling the effects of landscape, habitat and flowering time. Evolution 60(1): 39-55.
9. Ellis AG & AE Weis. 2006. Coexistence and differentiation of “flowering stones”: the role of local adaptation to soil microenvironment. Journal of Ecology 94: 322-335.
8. von Hase A, RM Cowling & AG Ellis. 2006. Petal movement in Cape wildflowers protects pollen from exposure to moisture. Plant Ecology 184: 75-84.
7. Franke DM, AG Ellis, M Dharjwa, M Freshwater, M Fujikawa, A Padron & AE Weis. 2006. A steep cline in flowering time for Brassica rapa in southern California: Population-level variation in the field and greenhouse. Intl. J of Plant Sciences 167(1): 83-92.
6. Desmet PG, RM Cowling, AG Ellis & RL Pressey. 2002. Integrating biosystematic data into conservation planning: perspectives from Southern Africa’s succulent Karoo. Systematic Biology 51(2): 317-331.
5. Ellis AG & SD Johnson. 1999. Do pollinators determine hybridization patterns in sympatric Satyrium (Orchidaceae) species? Plant Systematics and Evolution 219: 137-150.
4. Cowling RM, RL Pressey, AT Lombard, PG Desmet and AG Ellis. 1999. From representation to persistence: requirements for a sustainable system of conservation areas in the species-rich mediterranean-climate desert of southern Africa. Diversity and Distributions 5: 51-71.
3. Desmet PG, AG Ellis and RM Cowling. 1998. Speciation in the Mesembryanthemaceae. ALOE 35 (2): 38-43.
2. Ellis AG and JJ Midgley. 1996. A new plant-animal mutualism involving a plant with sticky leaves and a resident hemipteran insect. Oecologia 106: 478-481.
1. Johnson SD, AG Ellis, PJ Carrick, A Swift, S van Rensburg, N Horner and WJ Bond. 1993. Moth pollination and rhythms of advertisement and reward in Crassula fascicularis (Crassulaceae). South African Journal of Botany 59(5): 511-513.
Photo: Caroli Diener