Sensory adaptations to convergent micro-habitats - NERC GW4+ DTP

How do animals tune in to the most relevant information in their environment? Microhabitat partitioning between mimicry rings in Neotropical butterflies provides a case study in adaptation to different sensory environments. Species belonging to the same mimicry ring show convergence in microhabitat preference, while closely related species belonging to different mimicry rings quickly diverge in microhabitat preference, exposing closely related species to contrasting sensory environments. This dual pattern of convergence and divergence provides a range of opportunities for comparative analyses that aim to understand the role of brain and sensory evolution during ecological divergence. This project will use ithomiine butterflies as a study system to ask how species adapt to their sensory environment: For example, does sensory adaptation involve changes in perception or processing? How does selection for sensory specialisation shape peripheral and central neural structures? And does the convergent colonisation of the same microhabitat involve the same sensory adaptations?

Focusing largely on a large community of ~60 species of ithomiines in eastern Ecuador, you will combine ecological, anatomical and molecular approaches to ask how species adapt to distinct sensory environments. We welcome the input of the student and will shape the project to meet their particular interests. However, core objectives will likely include:

Objective 1: How does microhabitat structure affect the sensory environment?
Using a range of field measurements, including spectrophotometry and light polarimetry, you will quantify how forest structure affects the light environment in different microhabitats. In conjunction with models of photoreception in butterflies, you will explore how the visual information available to individuals varies across different mimicry rings.

Objective 2: Do convergent ecologies select for convergent adaptations?
Using available brain samples for ~55 species of ithomiines, in conjunction with museum collections, you will examine how eye structure and brain composition vary across species. You will test the power of phylogeny, ecology and mimicry to explain this variation.

Objective 3: How concordant are patterns of anatomical adaptation and molecular evolution?
Using recently sequenced head transcriptome data, together with published genomes, you will characterise the repertoire of chemosensory and photoreceptor genes in ithomiines. By targeted amplification of key loci, you will test whether sensory receptors show similar patterns of evolution to anatomical traits.