DOI: 10.5061/dryad.02v6wwqdg
title: Data from: Repeated evolution of reduced visual investment at the onset of ecological speciation in high-altitude <em>Heliconius</em> butterflies

description: Colonisation of new habitats is typically followed by divergent selection
 acting on traits that are immediately important for fitness. For example,
 differences between sensory environments are often associated with
 variation in sensory traits critical for navigation and foraging. However,
 the extent to which the initial response to novel sensory conditions is
 mediated by phenotypic plasticity, and the contribution of sensory or
 neural adaptation to early species divergence remains unclear. We took
 advantage of repeated cases of speciation in Heliconius butterflies with
 independent allopatric distributions in the west of the Colombian and
 Ecuadorian Andes. Using volumetric brain measurements, we analysed
 patterns of investment in primary sensory processing areas of the brain
 across different localities and habitats. We find that a higher-altitude
 species, Heliconius chestertonii, differs in levels of investment in
 visual and olfactory brain components compared to its lower altitude
 relative H. erato venus, mainly attributable to broad-sense heritable
 variation as inferred from comparisons between wild and common-garden
 reared individuals. We provide evidence that this variation is consistent
 with divergent selection, and compare these shifts with those reported for
 another high-altitude species, H. himera, and its parapatric lowland
 counterpart, H. erato cyrbia, to demonstrate parallel reductions in the
 size of specific optic lobe neuropils. Conversely, for the antennal lobe,
 we detected different trait shifts in H. himera and H. chestertonii
 relative to their lowland H. erato neighbours. Overall, our findings add
 weight to the adaptive potential of neuroanatomical divergence related to
 sensory processing during early species formation.
description: Tables 1-9 contain raw data and analyses results. Scripts are
 attached separatedly Supplementary information 1
 contains supplementary methods, results and discussion related to an
 ancestral state reconstruction of altitude
 in <em>Heliconius</em> species*.*
description: # Data from: Repeated evolution of reduced visual investment at the onset
 of ecological speciation in high-altitude *Heliconius* butterflies
 [https://doi.org/10.5061/dryad.02v6wwqdg](https://doi.org/10.5061/dryad.02v6wwqdg) ## Description of the data and file structure The data in the file Supplementary_Tables-Repeated_evolution_of_reduced_visual_investment_at_the_onset_of_ecological_speciation_in_hig-altitude_Heliconius_.xlsx contain the following: * Raw and log-transformed volumetric measurements of neuropils and allometric controls for wild-caught and insectary-reared *Heliconius erato venus* and *Heliconius chestertonii* individuals (S1). Column 1 indicates the individual's butterfly species, 2 its origin (wild caught or insectary reared), 3 its sex (male or female), 4 the year of collection and 5 its unique identification number. The neuropils (structures of the brain, as described in the article) shown are the medulla (ME), the lobula plate (LOP), the lobula (LO), the ventral lobula (vLO), the accessory medulla (AME), the anterior optic tubercle (AOTu), the antennal lobe (AL), the laminated (LA), the central complex (CC), the protocerebral bridge (PB), the posterior optic tubercle (POTu), the mushroom body (MB) and the central brain (CBR). The volumes of these structures are presented raw (cubic micrometers, columns 6-18) and log-transformed (columns 19-32),  * Log-transformed volumetric measurements of individuals of *Heliconius chestertonii*, *Heliconous erato venus*, *Heliconius himera* and *Heliconius erato cyrbia* (S2). Columns 1-5 convey species, origin, sex, year of collection and unique identification number. Column 7 indicates habitat type (high or low altitude forest) and column 8 indicates locality (Colombia or Ecuador). Columns 8-16 indicate neuropils selected for parallel evolution analyses (note this is a subset of, rather than all of the neuropils, as described in the article). * Results of allometric scaling analyses of brain variation between *Heliconius erato venus* and *Heliconius chestertonii* across groups of different origin (wild S3 and insectary S4) as well as within each species (wild vs insectary *Heliconius chestertonii*, S5 and wild vs insectary *Heliconius erato venus*, S6). In each case, it is indicated, for the neuropil under comparison, its location in the brain (optic lobe or central brain) and the parameters of tests for differences in slope, elevation and major-axis in scaling (each of which is described fully in the main article). * Results of Pst (neutral phenotypic variation)-Fst (neutral genomic variation) comparisons (S7) for different neuropils. For each neuropil, a Pst value is presented together with Pst estimate confidence intervals and the proportion of genomic Fst that lies under the Pst value. Columns 3-7 show Pst under strict sense heritability scenarios (squared h) ranging from 1 (column 3) to 0.5 (column 7). * Tests of correlation in log-transformed neuropil size in the medulla, the lobula and the lobula plate (S8).  * Neuropil volumes predicted from the allometric scaling function fitted for each species (S9). The parameters shown are the slope (column 5), the intercept (column 6) the mean volume of the allometric control (column 7), the lower confidence interval for mean volume of the allometric control (column 8), the upper confidence interval for the mean volume of the allometric control (column 9), the predicted neuropil volume (column 10), the lower confidence interval for neuropil volume (column 11) and the upper confidence interval for neuropil volume (column 12) The file "Supplemental Information.docx" contains details of an ancestral character reconstruction of altitude across butterfly species. ## Code/software The annotated scripts include SMATR regressions and Pst estimations as well as code for the variance partitioning approach used to infer levels of paralellism.