Seasonal environments drive convergent evolution of a faster pace-of-life in tropical butterflies

Abstract

Author contributions: SH, PMB and OB designed the study; SH carried out the experiment;EvB and OB collected data for habitat preference; CJB wrote a custom ImageJ macro; OB made figure illustrations; SH and EvB carried out analyses and wrote the manuscript with inputs from CJB, PMB and OB. All authors read and approved the final version of the manuscript. 2 ABSTRACTGlobal change can trigger shifts in habitat stability and shape the evolution of organismal lifehistory strategies, with unstable habitats typically favouring a faster pace-of-life. We test this hypothesis in species-rich Mycalesina butterflies that have undergone parallel radiations in Africa, Asia, and Madagascar. First, our ancestral state reconstruction of habitat preference, using ~85% of extant species, revealed that early forest-linked lineages began to invade seasonal savannahs during the Late Miocene-Pliocene. Second, rearing replicate pairs of forest and savannah species from the African and Malagasy radiation in a common garden experiment, and utilising published data from the Asian radiation, demonstrated that savannah species consistently develop faster, have smaller bodies, higher fecundity with an earlier investment in reproduction, and reduced longevity, compared to forest species across all three radiations. We argue that time-constraints for reproduction favoured the evolution of a faster pace-of-life in savannah species that facilitated their persistence in seasonal habitats.

Leafminer attack accelerates the development of soil‐dwelling conspecific pupae via plant‐mediated changes in belowground volatiles

“…Developmental time is an important component of insect fitness, the latter defined as the total number of offspring produced by an individual during its lifetime that survive to join the mating population of the next generation (Thompson et al ., 2011). Fast life‐history strategies including high growth rates and fecundity, at the cost of reduced longevity, allow the rapid increase in insect population sizes in seasonal habitats (Halali et al ., 2021). Faster pupal development may therefore increase L .…”

Genotype‐environment interaction reveals varied developmental responses to unpredictable host phenology in a tropical insect

“…Among lepidopterans, a particularly relevant comparison for this study comes from work conducted in the tropical genus Bicyclus and related taxa (e.g., Halali et al. 2021). Like E. hecabe , these butterflies breed across wet and dry seasons defined by spatio‐temporally unpredictable patterns of rainfall (Brakefield et al.…”

“…Compared with simply using pupal mass (as is conventional for these type of studies; e.g., Halali et al. 2021), this should arguably provide a more relevant phenotypic basis for assessing the functional and evolutionary genetic variation in growth and body size. Six individuals from the LQ treatment escaped and therefore could not be weighed but their data for development time were included in the analysis.…”

“…2017; Halali et al. 2021), the lion's share of research into such phenomena has dealt with temperate northern hemisphere butterfly species. A large body of work has characterized the environmentally cued juvenile growth decisions of Pieris , Pararge and Polygonia (reviewed by Gotthard 2008), Colias (Kingsolver and Buckley 2018) and a range of other temperate species (Leimar 1996; Tammaru et al.…”

Acaulescence promotes speciation and shapes the distribution patterns of palms in Neotropical seasonally dry habitats

“…Owing to their rainforest origin (Meerow et al 2015), the colonization and astonishing in situ radiation of Cocoseae in Neotropical seasonally dry habitats (Kissling et al 2012) are commonly linked to enabling traits that facilitated adaptation to increasingly dry and fire-prone environmental conditions (Freitas et al 2016, Bacon et al 2017. In fact, the diversification triggered by new ecological niches arising from climate change, such as seasonal habitats, often relies on adaptations in a suite of clades' life-history traits (Halali et al 2021). The acaulescent growth form is present in all the Cocoseae genera (e.g.…”