ORigin and evolutION of biodiversity at the microevolutionary and macroevolutionary scales in swallowtail butterflies

Patterns of species distribution across space, time, and taxonomic groups have long fascinated scientists. The origins of species diversity lie in speciation events, and uneven species richness is evidence of different rates of speciation. Understanding the drivers of biodiversity has taken two approaches: either focusing on allelic frequency variation and quantitative trait evolution within species (microevolution) or examining speciation rates and phenotypic evolution across species (macroevolution). However, a conceptual gap persists between these fields that questions the ability of microevolutionary processes to explain macroevolutionary rates. The concept of speciation is a critical link between these scales, with population-level processes theoretically influencing macroevolutionary rates. Reconciling micro- and macroevolution has produced conflicting evidence on the relationship between population-level processes and macroevolutionary rates, highlighting the need for further investigation. In this context, the ORION project will bridge the gap between micro- and macroevolution to address a pressing question in biodiversity research: can microevolutionary processes reliably predict macroevolutionary rates? Using a multidisciplinary approach focused on swallowtail butterflies (Papilionidae) – an iconic insect family with well-understood systematics and taxonomy of 640 globally distributed species – we will collect and integrate genomic, phenotypic, and ecological data at both species and subspecies levels. We will test whether population isolation, reproductive isolation, ecological and phenotypic differentiation, and population persistence (microevolutionary processes) play a role in controlling speciation rate and rates of phenotypic and niche evolution (macroevolutionary rates). The project aims to elucidate the intricate connections between micro- and macroevolutionary processes and to provide insights into the mechanisms that shape biodiversity gradients.