Department of Botany & Zoology, University of Stellenbosch, Private Bag X1, Matieland, 7602 South Africa
 


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Contact details:

Department of Botany & Zoology
University of Stellenbosch
Private Bag X1
Matieland 7602
South Africa

Tel: +27 21 808-3158
Fax: +27 21 808-2405
E-mail:
agellis@sun.ac.za

   

Allan Ellis

Prof. Allan Ellis


Publications

Primary research interests

Evolution of specialization • floral diversification • plant-insect interactions • plant-insect diversity relationships • insect behaviour, especially as it relates to floral evolution • colour • dispersal evolution • the origin and maintenance of species • species coexistence • diversification of the Cape flora and fauna

My 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).


Ongoing research projects

1. Biotic context and the floral diversification of beetle daisies
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.

2. The role of filtering in the evolution of floral specialization
Also in the Gorteria diffusa system, we are examining the influence of selection imposed by effective pollinators, ineffective pollinators and floral antagonists (nectar and pollen thieves) on floral specialization.

3. Floral evolution across geographic mosaics of multiple effective visitors
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)  

4. Pollen limitation and pollinator dependence in the Cape flora.
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.

5. Structural colour in flowers of the Cape flora
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)

6. Linking dispersal in space and time and pollination dynamics of Namaqua daisies 
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) 

7. Evolution of specialization and community assembly of restio leaf-hoppers
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)

8. Rhizobia-legume interaction networks in an invasion context
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)

9. Evolution of minutism and its effects on plant diversification
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)


Postgrads / lab members

Current:

Willem Augustyn  (PhD) “Evolutionary drivers of temporal and spatial host-use patterns in restio leafhoppers Cephalelus Percheron (Cicadellidae: Cephalelini)” (with B Anderson)

Jurene Kemp (PhD) “Pollinator specialization resulting from the filtering of less effective pollinators”

Jan-Hendrik Keet (PhD) “Understanding the biodiversity impacts of invasive species: Investigating changes in below- and above-ground mutualistic networks in response to invasions” (with JJ Le Roux, C Hui)

Blessing Mutiti (Hons) “Insights into the identity and diversity of rhizobial symbionts associated with South African Rooibos tea (Aspalathus linearis, Burm. f. Dahlg., Fabaceae): a comparison between wild and cultivated populations”. (with JJ Le Roux)

Nicolas Hosking (Hons) “Insights into the architecture of rhizobial-legume interactions and their responses to biological invasions” (with JJ Le Roux)

Completed:

Postdoc

James Rodger (2012 - 2015)  “Evolution of selfing in the Cape flora”

Natasha Mavengere (2012 - 2013) “Specialization in rhizobial interactions and its role in invasions” (with J Le Roux)

PhD

Caroli De Waal (2012 – 2015) “The ecology and evolution of dispersal and dormancy: risk-reducing strategies in a changing climate” (with B Anderson)

Marinus De Jager (2009 - 2013) “Phylogeographic and behavioural variation in a pollinator as a driver of floral divergence in the beetle daisy, Gorteria diffusa (Asteraceae)”.

Tony Knowles (2009 - 2012) “The ecological and financial feasibility of avoided deforestation and carbon sequestration activities in sub-Saharan Africa” (with B Scholes, A. van Jaarsveld)

MSc

Jurene Kemp (2013 - 2014) “Plant-insect diversity relationships in the Cape Floristic Region”

Hannes Wiese (2012 – 2013) “Co-diversification and the evolution of host choice in a plant-insect-symbiont-parasitoid interaction in the CFR.” (with J Le Roux)

Enelge Gildenhuys (2012 - 2013) “Unravelling taxonomic uncertainties among Balloon vine species within the genus Cardiospermum using phylogenetic and biological species concepts.” (with J Le Roux)

Petra Ros. (2008-2010) “Pollinator driven floral variation in Tritoniopsis revoluta” (with B Anderson)

Honours

Lize-Mari van Zyl (2014) “Impacts of rhizobial mutualists and soil properties on the performance of invasive wattles from the genus Acacia in South Africa’s Cape Floristic Region” (with JJ Le Roux)

Andre Vermeulen (2013) “Insect diversity and herbivore specialization on Erica species in Cape fynbos.”

Ryan Kaye (2012) “Relating recruitment strategy to pollen limitation and gender-specific selection on floral traits in Oxalis” (with L Dreyer)

Hannes Wiese (2011) “Phylogeography of Cephalelus leafhoppers and their bacterial endosymbionts”

Nadene Smith (2009) “Does pollinator abundance and diversity differ between burnt and unburnt veld?” (with A Pauw, B Anderson)

DuToit Malherbe (2009) “The influence of fire on pollination rates in the Cape fynbos” (with A Pauw, B Anderson)

Marinus De Jager (2008) “The assembly of flower colour within communities of Oxalis (Oxalidaceae) through pollinator-mediated selection” (with L Dreyer).

Muri Soares (2007) Community-level analysis of floral UV reflectance. (with N Bergh at UCT)

Vera Hoffman (2007) “Components of reproductive isolation between Jamesbrittenia racemosa and J. pedunculosa (Manulae)” (with GA Verboom at UCT)

Amrei von Hase (2000) “Petal movement in Cape wildflowers protects pollen from exposure to moisture” (with RM Cowling at UCT)

Visiting research students

Sam Brockington (2011, 2014) “Trait integration in Gorteria” (postdoc Cambridge University)

Gregg Mellers (2014) “Evolutionary history of Gorteria diffusa” (PhD student with B. Glover at Cambridge University)

Johanna Ecklund (2013) “Crypsis through the eyes of a predator” (undergraduate from Lund University, Sweden)

Florent Grenier (2013) “Reproductive isolation in coexisting Haworthia species” (MSc student from Ecole Normale Supérieure of Paris)

Rachel Walker (2011) “Evolutionary development of Gorteria petal spots” (PhD student with Beverley Glover at Cambridge University)

Meredith Thomas (2009) “Evolutionary development of Gorteria petal spots” (PhD student with Beverley Glover at Cambridge University)


Teaching

Undergraduate: introduction to evolution, community ecology, field ecology techniques, angiosperm diversification
Honours: evolutionary ecology


Publications

for citation metrics see Google Scholar
https://scholar.google.co.za/citations?user=oYDWGmYAAAAJ&hl=en&oi=ao

for pdfs see Research Gate
https://www.researchgate.net/profile/Allan_Ellis/publications

2015

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

2014

43. Ellis AG, T van der Niet, SD Johnson, GA Verboom & HP Linder. 2014 In Press. 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 In Press. 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

2013

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.

2012

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.

2011

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.

2010

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.

Before 2010

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.