We have a new paper out in Molecular Ecology where we investigate variation in iridescent structural colour in the mimetic butterflies Heliconius erato and Heliconius melpomene. Both of these species vary from having to blue iridescent colour in Colombia to being matt black in Panama.
In her PhD thesis work Emma Curran showed that the colour change is more gradual in H. melpomene than H. erato and this is most likely due to weaker selection acting on the colour in this species. She also investigated population genomic structure and fund that while H. erato clusters into two different groups in Panama and Colombia, H. melpomene doesn’t. While the colour change happens in a similar place in both species, strongly suggesting that mimicry between the species has been important in its evolution, the differences between species hint at different evolutionary histories.
This is the first time that variation in iridescent structural colour has been investigated in wild Heliconius populations. This trait is also different to the colour pattern traits that have most commonly been investigated in Heliconius because it is a quantitative trait, controlled by many loci, rather being controlled by a single genetic locus. Our results therefore also shed light on the major question of how differences in quantitative traits evolve.
We have a new paper out in Evolution about the effects of altitude and life history on wing size and shape in Heliconius butterflies. Work done by PhD student Gabriela Montejo‐Kovacevich, and former Masters student Jennifer Smith, shows that species found higher up the slopes of the Andes tend to have larger and rounder wings. We also found that in species with gregarious larvae, females were larger than males, while the opposite was the case for species with solitary larvae. This is the first publication from our NERC funded project on adaptation to altitude in tropical insects.
We have a new paper out in the Journal of the Royal Society, Interface Focus, as part of a special issue on structural colour. Mel has used the variation in iridescent blue colour that we see in crosses between blue and black subspecies of Heliconius erato, to investigate the genetics of this trait. She shows that it is controlled by multiple genes, one or more of which are located on the Z sex-chromosome. Juan also investigates how one aspect of scale structure (ridge spacing) varies in these crosses. He shows that closer ridge spacing produces brighter blue colour, and that this trait also appears to be controlled by several genes. This is the first investigation of the genetics of structural colour in Heliconius. In fact, very little is known about the genetic control of structural colour in any animal. We plan to follow up this work by investigating the molecular genetics of structural colour production in these butterflies.
Congratulations to Emma who successfully defended her thesis at the end of November. Mel made this amazing hybrid zone cake to celebrate. It (very accurately) shows the hybrid zone that Emma worked on for her thesis, where the butterflies go from being black (in the north) to blue (in the south).
We are seeking an enthusiastic student with interests in ecology, evolution and genetics to work on a project investigating thermal adaptation in tropical Andean butterflies. Understanding organisms’ adaptation to their thermal environment is important for predicting responses to climate change. Tropical insects make up around half of all species on Earth, and yet very little is known about their thermal ecology. Butterflies are one of the best-studied insect groups concerning thermal adaptation, but relatively little is known about the responses of tropical species to climate change.
The Heliconius butterflies have been extensively studied, and there is good information about the distributions of species in this genus, but very little is known about what determines species ranges (e.g. temperature versus rainfall), or how ranges have shifted. Many of the species in the genus are found in and around the Andes, and it seems likely that thermal adaptation plays a role in delimiting niches in this area, and in driving distributions to shift uphill, but this has not previously been investigated. Excellent genomic resources are available for Heliconius, which have been used to investigate genes underlying adaptation and speciation. This provides the opportunity to investigate thermal adaptation in this group at multiple levels, from genes to populations, species and communities, to investigate and predict responses to climate change.
The project can be tailored to the interests of the student but could include a combination of field work, physiological and genetic laboratory work, computational analysis including analysis of genomic data and species distribution modelling, and working with historical collections and records. Key questions that could be addressed include: understanding how temperature affects survival, growth and fecundity of Heliconius species found at different elevations across the Andes; if and how these parameters relate to species distributions and range limits; if and how species ranges are changing or could change in response to habitat and climate change; the genetic basis of thermal adaptation and whether genetic changes have occurred or are they likely to occur in response to climate change.
This PhD will be linked to a newly funded NERC grant exploring variation in thermal adaptation across altitudinal gradients in Heliconius and the genetic basis of this. This collaborative project is led by Dr Nadeau in Sheffield, with Prof. Jiggins in Cambridge, Dr Saastamoinen in Helsinki and Dr Bacquet at the Amazonian Regional University, IKIAM, in Ecuador. The PhD student will expand this work to understand the implications for species distributions and climate change, with guidance from co-supervisor Prof. Hill in York.
Select ‘Standard PhD’ and ‘Animal and Plant Sciences (APS)’ as the department
Fill in the Title of the project (‘Understanding temperature adaptation in tropical Andean butterflies’) and the name(s) of the supervisors (‘Dr Nicola Nadeau and Prof. Jane Hill’).
‘Study term,’ can be full-time or part-time
The starting date of PhD will be the start of the next academic year- 1 Oct 2019
‘Funding stage‘ on the form will be ‘project studentship‘
Contact Nicola Nadeau for informal enquiries and further information.
Fully funded studentships cover: (i) a stipend at the UKRI rate (at least £14,777 per annum for 2019-2020), (ii) research costs, and (iii) tuition fees. Studentship(s) are available to UK and EU students who have been living in the UK for the last three years immediately before the start of the studentship. EU nationals who do not meet the residency requirement are still eligible for ‘fees only award’, which covers fees and a research grant (RTSG), but no stipend.
This PhD project is part of the NERC funded Doctoral Training Partnership “ACCE” (Adapting to the Challenges of a Changing Environment). ACCE is a partnership between the Universities of Sheffield, Liverpool, York, CEH, and NHM.
Shortlisted applicants will be invited for an interview to take place at the University of Sheffield the w/c 11th February 2019.
Nadeau NJ et al. 2014 Population genomics of parallel hybrid zones in the mimetic butterflies, H. Melpomene and H. erato. Genome Res. 24, 1316–1333. DOI:10.1101/gr.169292.113
Scriven SA, Beale CM, Benedick S, Hill JK. 2017 Barriers to dispersal of rain forest butterflies in tropical agricultural landscapes. Biotropica 49, 206–216. DOI:10.1111/btp.12397
Rosser N, Phillimore AB, Huertas B, Willmott KR, Mallet J. 2012 Testing historical explanations for gradients in species richness in heliconiine butterflies of tropical America. Biol. J. Linn. Soc. 105, 479–497. DOI:10.1111/j.1095-8312.2011.01814.x
Next week the university is hosting the Festival of the Mind a collaboration between our academic colleagues and experts from Sheffield’s cultural and creative industries.
We have been working with artist Sarah Jane Palmer to create artwork telling the story of some our research. this will be on display in the millennium gallery from Thursday 20 – Thursday 27 September as part of the Futurecade. Sarah will also be giving a talk at 4pm on 20 September, with a question and answer session with Nicola.
We are currently advertising two positions on this grant:
A 3-year postdoc position. This will It will involve intensive rearing and phenotyping of butterflies to characterize both inter- and intra-specific differences in thermal adaptation at different altitudes in the Andes. This will be followed by generation and analysis of high-throughput genomic data to identify underlying genetic differences. The rearing and phenotyping will be conducted in Ecuador, therefore you will be expected to spend significant amounts of time working in Ecuador with partner organisations. You will have a strong commitment to evolutionary research with skills in at least one of:
analysis of large genomic data sets; analysis of quantitative trait variation; or insect ecophysiology. Being able to communicate in Spanish would also be an advantage.You will hold a PhD or equivalent experience in evolutionary biology and will have experience of research in evolutionary genetics and analysing large data sets.
A 2-year graduate research assistant position. This will involve assisting the postdoc, primarily with rearing and phenotyping of butterflies to characterize both inter- and intraspecific differences in thermal adaptation at different altitudes in the Andes. The rearing and phenotyping will be conducted in Ecuador, therefore you will be expected to spend significant amounts of time working in Ecuador. You will have an interest and enthusiasm for evolutionary research with good attention to detail and experience of accurate collection and handling of data. You will have a good honours degree or equivalent experience in a biological discipline and experience of recording and checking numerical data in a research context. You will have an enthusiasm for evolutionary/ ecological/ entomological research and experience of rearing insects. Being able to communicate in Spanish would also be an advantage.
The closing date for applications for both positions is the 18th of June 2018. The starting dates for both positions are around the 1st of September 2018, but there may be some flexibility. Contact Nicola for further information or informal enquiries about either position.