Climate, Connectivity, and Diversification: The Biogeographic History of Tropical Butterflies

Supervisor: Andrea Manica

Co-supervisor: Joana Meier

Project Summary:

Understanding how biodiversity originates and is maintained across space remains a central challenge in biogeography and evolutionary biology. Although phylogenetic and species distribution approaches are widely used to infer patterns of diversification, they often treat species as homogeneous units and therefore overlook the demographic and evolutionary processes that generate geographic structure within species. This project will investigate how historical climate change, landscape dynamics, and dispersal have shaped patterns of genetic differentiation and diversification across space, ultimately contributing to the origins of biodiversity.
Using population genomics, students will reconstruct the demographic history, connectivity, and spatial structure of populations through time. The focus will be on Ithomiini butterflies, a highly diverse Neotropical radiation that exhibits substantial variation in geographic ranges, habitat specialization, and levels of population differentiation. Whole-genome data will be used to infer historical isolation, range expansion, gene flow, and population fragmentation, and these patterns will be linked to reconstructions of past climatic and environmental change. By integrating genomic and biogeographic approaches, the project will test how environmental stability, dispersal barriers, and historical refugia have influenced diversification processes and the emergence of evolutionary lineages. The research will provide new insights into the mechanisms generating species richness in tropical ecosystems and the factors determining genetic and geographic structure within species.

Type of Work:

The student will use climate informed population genetic models, a framework to quantitively combine ecological, genetic and climatic information, to study responses of species to past climate change. The work is computer based, and requires mastering a number of disciplines. The student should be proficient in R programming, and will join a group of students and postdocs who work together in developing tools to ask ecological and evolutionary questions. They will participate in weekly hackathons, facilitating their up-skilling in coding (in R, and potentially other languages). 

Importance of the area of research concerned:

Biogeography seeks to explain one of the most fundamental questions in biology: why species occur where they do and how new species arise over time. Understanding how historical climate change, dispersal, and geographic barriers have shaped genetic diversity provides crucial insights into the processes that generate and maintain biodiversity. Advances in genomics now allow us to reconstruct these evolutionary histories in unprecedented detail, revealing the mechanisms underlying population divergence and speciation. This knowledge is particularly important in tropical ecosystems, where much of the world's biodiversity has evolved but where the origins of species richness remain poorly understood. By linking genomic patterns to environmental change, this research helps explain both the emergence of biodiversity and its resilience to future environmental challenges.

References:

Xue, Z., Paijmans, JLA., Pozzi, AV., Leedham, S., Leonardi, M., Padilla-Iglesias, C., Colucci, M., Hovhannisyan, A., & Manica, A. (2025). Climate Shaped the Global Population Structure of Leopards and their Extinction in Europe. bioRxiv. 2025.10. 03.680393 Miller, EF., Leonardi, M., Xue, Z., Beyer, R., Krapp, M., Somveille, M., Somma, GL., Delser, PM., & Manica, A. (2021). Post-glacial expansion dynamics, not refugial isolation, shaped the genetic structure of a migratory bird, the yellow warbler. BioRxiv. 2021.05. 10.443405