Marianne ELIAS

Publications before 2014

Presentation

CV

Since December 2009 : CNRS researcher at the National Museum of Natural History, Paris, France

• Since 2022: STRI Reasearch Associate (Panama)
• Since 2017: CNRS DR2
• 2016 : HDR
• 2013 : CNRS CR1
• Dec. 2009 : CNRS researcher at MNHN (CR2)
• 2009. Postdoc, Imperial College London, UK
• 2005 – 2008. Postdoc, Universities of Edinburgh and Cambridge, UK
• 2001 – 2004. Postdoc, Universities of Helsinki and Oulu, Finland
• 1996 – 2000. PhD in Evolutionary Biology, University of Montpellier II, France.

Main research interests

Understanding why so many species exist represents a major challenge for modern evolutionary biology, and is a prerequisite to define sensible conservation strategies. Our research on biodiversity focuses on 1) factors involved in speciation (how species originate) using a range of approaches that span different spatial, temporal and taxonomical scales, and 2) dynamic processes that permit multiple species to coexist, particularly in biodiversity “hotspots”.
My team mostly uses ithomiine butterflies as a model group (Nymphalidae : Ithomiini, 380 species). Ithomiines form a diverse neotropical tribe, that inhabit wet forest and span a wide range of elevation. All ithomiine species engage in Müllerian mimicry : co-occurring distasteful species converge in warning colour patterns, thereby decreasing the per-capita cost of predation (mutualistic mimicry). Mimetic butterfly locally form ‘mimicry rings’ (Figure 1), which comprise several species sharing a common warning pattern

Figure 1. Four mimicry rings formed by ithomiine species in Añangu, Ecuador

Credits

© MNHN

Projects

Patterns of diversification in mimetic tropical butterflies using species-level phylogenies

• Team members involved : Nicolas Chazot (former PhD), Lisa de Silva (former postdoc)
• Main collaborators : Keith Willmott (University of Gainesville, USA), André Freitas (University of Campinas, Brazil), Gerardo Lamas (Museo de Historia Natural, Lima, Peru), Carlos Eduardo Giraldo (Universidad de Medellin, Colombia)

We generate dated species-level molecular phylogenies of ithomiine genera or subtribes (and ultimately of the whole tribe) to investigate temporal and geographic patterns of diversification and trait evolution (e.g., wing colour pattern, biotic and abiotic niches) (Figure 2). Specifically we look for :

• Phylogenetic signatures of the role of major geological events (e.g. Andes uplift, Pebas system, closure of Panama isthmus)
• Phylogenetic signatures of adaptive radiations, expansion or decline
• Evidence for changes of diversification rates driven by a change of character state
• Evidence for association between changes in character state and speciation events
• Evidence for selection

 

Figure 2 : Comprehensive molecular phylogeny of the genus Napeogenes

Credits

© MNHN

Community ecology

Team members involved : Nicolas Chazot (former PhD), Thomas Aubier (PhD CEFE, Montpellier), Yann Le Poul (former PhD)

Main collaborators : Keith Willmott (University of Gainesville, USA), Chris Jiggns (University of Cambridge, UK), Zach Gompert (University of Utah, USA)

Forces that govern species assemblages in communities are complex, and can be classified into 3 categories : ’neutral’ forces (dispersal, drift), habitat filtering (linked to local adaptation) and interactions among species. We use community species composition, trait and abundance data and phylogenies of local species to investigate at various spatial scales (local community or entire region) the respective roles of habitat filtering and ecological niche (micro and macrohabitat) and of interspecific interactions (e.g., competition, mutualisic mimicry, Figure 3). In addition, we explore the phylogenetic structure of trophic networks, such as insects and their hostplants.

 

Figure 3. Mimicry drives microhabitat niche convergence among ithomiine butterflies

Credits

© MNHN

The ecology and the genomics of speciation

Team members involved : Melanie McClure (postdoc), Florence Prunier (AI), Céline Houssin (Tech.), Yann Le Poul (former PhD), Jérémy Gauthier (postdoc INRIA, Rennes)

Main collaborators : Claire Lemaitre and Fabrice Legeai (GenScale, Rennes), Emmanuelle Jacquin-Joly (iEES, Paris), Annabel Whibley (JIC, Norwich, UK), Kanchon Dasmahapatra (University of York, UK), Mathieu Joron (CEFE, Montpellier).

We focus on eight ithomiine species to measure divergence and experimentally test the role of various factors, such as colour patterns, hostplant, microhabitat and pheromones in reproductive isolation among parapatric subspecies (Figure 4). In parallel, we explore population genetic structure and the extent of genetic differentiation among these taxa using markers generated by high throughput sequencing.

Figure 4. Mating between Andean and Amazonian subspecies of Ithomia salapia

Credits

© MNHN

Evolution of transparency in Lepidoptera

Team members involved : Charline Pinna (Master’s), Monica Arias (postdoc CEFE, Montpellier)

Main collaborators : Doris Gomez (CEFE, Montpellier), Serge Berthier (INSP, Paris) and Christine Andraud (CRC, Paris), Nipam Patel (university of Berkely, USA), Johanna Mappes (University of Jyvaskyla, Finland)

Lepidoptera have evolved large wings covered with scales, which are involved in hydrophobicity, thermoregulation, flight aerodynamics and most importantly colour patterns. Yet, a number of lepidopteran lineages harbour partially or totally transparent wings… and many of those are chemically-defended, mimetic butterflies (Figure 5). At the interface between physics, evolutionary biology and developmental biology, we image wing structures (scales and membrane nanostructures) and measure optical properties of wings of transparent butterflies to understand their development, evolution, in light of their ecology. We also carry out experiments to investigate the impact of prey transparency on predators.

Figure 5. Hypomenitis enigma

Credits

© MNHN

Other projects

I collaborate with Doris Gomez (CEFE, Montpellier) to study the evolution of iridescent colour patterns in humming birds, using optical measures and comparative analyses (PhD of Hugon Gruson). I collaborate with Violaine Llaurens (ISYEB, Paris) and Bastien Nay (LSO, Palaiseau) to study the evolution of toxicity in Heliconius and Ithomiini butterflies, using chemical analyses and comparative analyses (PhD of Ombeline Sculfort). I am also part of the ANR project SPHINX led by Rodolphe Rougerie, which aims at unravelling spatial and temporal patterns of diversification of the moths Saturniidae and Sphingidae (PhD of Pierre Arnal).

Main current fundings

As PI

• 2017 - 2019 : HFSP research grant (Development, functions, and evolution of transparency in butterflies : an interdisciplinary approach)
• 2015 - 2018 : ANR SPECREP (Repeatability of the speciation process in butterflies : natural replicates in a suture zone system)

As partner

• 2017 - 2020 : ANR CLEARWING (Transparency : physical origin, adaptive functions and evolution in clearwing butterflies)
• 2017 - 2020 : ANR SPHINX (Understanding and predicting species adaptation to environmental changes in Insectes)