1
|
Wright DS, Rodriguez-Fuentes J, Ammer L, Darragh K, Kuo CY, McMillan WO, Jiggins CD, Montgomery SH, Merrill RM. Selection drives divergence of eye morphology in sympatric Heliconius butterflies. Evolution 2024; 78:1338-1346. [PMID: 38736286 DOI: 10.1093/evolut/qpae073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 05/02/2024] [Accepted: 05/10/2024] [Indexed: 05/14/2024]
Abstract
When populations experience different sensory conditions, natural selection may favor sensory system divergence, affecting peripheral structures and/or downstream neural pathways. We characterized the outer eye morphology of sympatric Heliconius butterflies from different forest types and their first-generation reciprocal hybrids to test for adaptive visual system divergence and hybrid disruption. In Panama, Heliconius cydno occurs in closed forests, whereas Heliconius melpomene resides at the forest edge. Among wild individuals, H. cydno has larger eyes than H. melpomene, and there are heritable, habitat-associated differences in the visual brain structures that exceed neutral divergence expectations. Notably, hybrids have intermediate neural phenotypes, suggesting disruption. To test for similar effects in the visual periphery, we reared both species and their hybrids in common garden conditions. We confirm that H. cydno has larger eyes and provide new evidence that this is driven by selection. Hybrid eye morphology is more H. melpomene-like despite body size being intermediate, contrasting with neural trait intermediacy. Overall, our results suggest that eye morphology differences between H. cydno and H. melpomene are adaptive and that hybrids may suffer fitness costs due to a mismatch between the peripheral visual structures and previously described neural traits that could affect visual performance.
Collapse
Affiliation(s)
- Daniel Shane Wright
- Division of Evolutionary Biology, Faculty of Biology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Juliana Rodriguez-Fuentes
- Division of Evolutionary Biology, Faculty of Biology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Lisa Ammer
- Division of Evolutionary Biology, Faculty of Biology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Kathy Darragh
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
- Smithsonian Tropical Research Institute, Gamboa, Panama
| | - Chi-Yun Kuo
- Division of Evolutionary Biology, Faculty of Biology, Ludwig Maximilian University of Munich, Munich, Germany
| | | | - Chris D Jiggins
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
- Smithsonian Tropical Research Institute, Gamboa, Panama
| | - Stephen H Montgomery
- Smithsonian Tropical Research Institute, Gamboa, Panama
- School of Biological Science, University of Bristol, Bristol, United Kingdom
| | - Richard M Merrill
- Division of Evolutionary Biology, Faculty of Biology, Ludwig Maximilian University of Munich, Munich, Germany
- Smithsonian Tropical Research Institute, Gamboa, Panama
| |
Collapse
|
2
|
Rossi M, Hausmann AE, Alcami P, Moest M, Roussou R, Van Belleghem SM, Wright DS, Kuo CY, Lozano-Urrego D, Maulana A, Melo-Flórez L, Rueda-Muñoz G, McMahon S, Linares M, Osman C, McMillan WO, Pardo-Diaz C, Salazar C, Merrill RM. Adaptive introgression of a visual preference gene. Science 2024; 383:1368-1373. [PMID: 38513020 DOI: 10.1126/science.adj9201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 01/30/2024] [Indexed: 03/23/2024]
Abstract
Visual preferences are important drivers of mate choice and sexual selection, but little is known of how they evolve at the genetic level. In this study, we took advantage of the diversity of bright warning patterns displayed by Heliconius butterflies, which are also used during mate choice. Combining behavioral, population genomic, and expression analyses, we show that two Heliconius species have evolved the same preferences for red patterns by exchanging genetic material through hybridization. Neural expression of regucalcin1 correlates with visual preference across populations, and disruption of regucalcin1 with CRISPR-Cas9 impairs courtship toward conspecific females, providing a direct link between gene and behavior. Our results support a role for hybridization during behavioral evolution and show how visually guided behaviors contributing to adaptation and speciation are encoded within the genome.
Collapse
Affiliation(s)
- Matteo Rossi
- Faculty of Biology, LMU, Munich, Germany
- Smithsonian Tropical Research Institute, Gamboa, Panama
| | | | | | - Markus Moest
- Department of Ecology and Research Department for Limnology, Mondsee, University of Innsbruck, Innsbruck, Austria
| | | | | | | | - Chi-Yun Kuo
- Faculty of Biology, LMU, Munich, Germany
- Smithsonian Tropical Research Institute, Gamboa, Panama
| | - Daniela Lozano-Urrego
- Faculty of Biology, LMU, Munich, Germany
- Faculty of Natural Sciences, Universidad del Rosario, Bogotá, Colombia
| | | | - Lina Melo-Flórez
- Faculty of Biology, LMU, Munich, Germany
- Faculty of Natural Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Geraldine Rueda-Muñoz
- Faculty of Biology, LMU, Munich, Germany
- Faculty of Natural Sciences, Universidad del Rosario, Bogotá, Colombia
| | | | - Mauricio Linares
- Faculty of Natural Sciences, Universidad del Rosario, Bogotá, Colombia
| | | | | | | | - Camilo Salazar
- Faculty of Natural Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Richard M Merrill
- Faculty of Biology, LMU, Munich, Germany
- Smithsonian Tropical Research Institute, Gamboa, Panama
| |
Collapse
|
3
|
Wright DS, Manel AN, Guachamin-Rosero M, Chamba-Vaca P, Bacquet CN, Merrill RM. Quantifying visual acuity in Heliconius butterflies. Biol Lett 2023; 19:20230476. [PMID: 38087940 PMCID: PMC10716659 DOI: 10.1098/rsbl.2023.0476] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Heliconius butterflies are well-known for their colourful wing patterns, which advertise distastefulness to potential predators and are used during mate choice. However, the relative importance of different aspects of these signals will depend on the visual abilities of Heliconius and their predators. Previous studies have investigated colour sensitivity and neural anatomy, but visual acuity (the ability to perceive detail) has not been studied in these butterflies. Here, we provide the first estimate of visual acuity in Heliconius: from a behavioural optomotor assay, we found that mean visual acuity = 0.49 cycles-per-degree (cpd), with higher acuity in males than females. We also examined eye morphology and report more ommatidia in male eyes. Finally, we estimated how visual acuity affects Heliconius visual perception compared to a potential avian predator. Whereas the bird predator maintained high resolving power, Heliconius lost the ability to resolve detail at greater distances, though colours may remain salient. These results will inform future studies of Heliconius wing pattern evolution, as well as other aspects in these highly visual butterflies, which have emerged as an important system in studies of adaptation and speciation.
Collapse
Affiliation(s)
- Daniel Shane Wright
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
| | - Anupama Nayak Manel
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
| | - Michelle Guachamin-Rosero
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
- Universidad Regional Amazónica IKIAM, Tena, Ecuador
| | - Pamela Chamba-Vaca
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
- Universidad Regional Amazónica IKIAM, Tena, Ecuador
| | | | - Richard M. Merrill
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
| |
Collapse
|