DOI: 10.5061/dryad.m63xsj486
title: Ecomorphological convergence following niche shifts in montane ground beetles (Carabidae: Nebria)

description: Aim: A critical step towards uncovering generalizable patterns of
 phenotype-niche relationships is understanding how functional traits have
 evolved as species occupy new habitats. Ecomorphological traits impact how
 organisms function in their environment and are predictive of habitat use
 and niche. Studying ecomorphological variation in the context of strong
 environmental filtering can provide opportunities to understand the role
 of convergent evolution in forming trait-habitat use patterns. By
 integrating a molecular phylogeny, habitat use, and morphometrics, this
 study aimed to understand the role of ancestry and convergent evolution in
 ecomorphological trait evolution.   Location: Montane
 and alpine streambeds, talus, and snowfields in Holarctic mountain ranges
 (0-5000 m. above sea level).   Time period: 1970-2021  
 Major Taxa Studied: Seventy-nine species comprising three species
 complexes in the ground beetle genus Nebria (Carabidae: Nebriini).
   Methods: Morphological measurements including pronotal
 ratio (widest point divided by the base), elytral length, elytral ratio
 (length divided by width), antennal scape length, and pronotal and elytral
 shape (Fourier decomposition) were used in this study, in conjunction with
 measurements of habitat use habitat where specimens were collected.
 Morphological variation was examined in relation to habitat use and
 phylogenetic relatedness, and morphological trait evolution was tested for
 convergence.   Results: Ecomorphological traits are
 evolving slower than expected under a null model of Brownian motion
 evolution. Nebria species cluster in multivariate morphospace according to
 relatedness, but habitat use and relatedness together are the best
 predictors of morphological variation. There is evidence for convergence
 in riparian species based on morphologicy alone, and additional evidence
 for morphological convergence in riparian and alpine species when
 phylogenetic distance is considered.    Main
 conclusions: In species assemblages of Nebria, we found evidence of rapid
 diversification followed by a slow rate of ecomorphological evolution,
 with convergent evolution playing a significant role in shaping
 trait-habitat use patterns and niche acquisition.
description: Specimens from the California Academy of Sciences were used.
 Morphometrics were collected by photographing specimens on a Leica camera
 (Leica AG, 2020) and measured in ImageJ. Silhouettes of morphological
 features were created in Inkscape (Inkscape, 2020) and analyzed using
 Fourier decomposition analysis using the R package momocs (Bonhomme et
 al., 2014). Methods from Sansalone et al., 2020 and Stayton, 2015 were
 used to test for convergence. The R package RRphylo (Castiglione et al.,
 2019) was used to assess the rate of trait evolution. The online database
 Worldclim (Fick & Hijmans, 2017) was used to extract bioclimatic
 data for species. Google earth (Google Maps 2021) was used to estimate
 lat/long and elevation of species based on museum locality data. All
 analyses were performed using R statistical software v4.2.0.1 (R Core
 Team, 2021).
description: # Ecomorphological convergence following niche shifts in montane ground
 beetles (Carabidae: Nebria)
 [https://doi.org/10.5061/dryad.m63xsj486](https://doi.org/10.5061/dryad.m63xsj486) ## Description of the data and file structure "Ecomorphological_convergence_following_niche_shifts_in_montane_ground_beetles_(Carabidae_Nebria)_all_specimens_no_NA.csv" contains measurements of each individual specimen. Included in this file are the variables (in order left to right): subspecies: Subspecies identifiers id: An id number to distinguish specimens sex: The sex of the specimen pronotum_wide: The pronotum width at the widest point (mm) pronotum_base: Pronotum width at the posterior end (mm) elytra_width: Elytron width at the widest point (mm) elytra_length: Elytron length at the longest point (mm) scape: Scape length (mm) elevation: Elevation where the specimen was collected (m) substrate: Substrate type where the specimen was collected (1 = gravel (&lt;10 cm in diameter), 2 = medium rocks (10-50 cm in diameter), 3 = large rocks (&gt;50 cm in diameter, 4 = vegetation covered rocks, 5 = alpine (talus and/or snowfield)) color: Color used to identify the species for making figures pronotum_ratio: The ratio of the pronotum  at its widest point to its base index: An identifying index number Color: An identifying color (but not saved as type "character") elytra_ratio: The ratio of the elytron at its widest point to its length E1 - 28: Fourier decomposition features for elytral shape (denoted by the letter E). P1 - 44: Fourier decomposition features for pronotal shape (denoted by the letter P). Some entries under the last two variables are "NA". This stands for "not applicable" because these specific Fourier features were not required to accurately estimate the shape of the morphology.  The zip file named "Nebria_spp" contains images of all the specimens used in this study. Elevation and coordinates (WGS84) for collection localities was estimated using Google Maps. Climatic variable information can be accessed at this site: [https://www.worldclim.org/data/worldclim21.html](https://www.worldclim.org/data/worldclim21.html). Variables used in this study included: mean annual temperature (Celsius), mean maximum temperature (Celsius), mean minimum temperature (Celsius), mean solar radiation (kJ per square meter per day), mean vapor pressure (kPa), mean precipitation (mm) and mean wind speed (meters per second). ## Code/Software R statistical software v4.2.0.1 was used for analysis (R Core Team 2021). The file "Ecomorphological convergence following niche shifts in montane ground beetles (Carabidae Nebria).R" contains analyses performed in this study.