DOI: 10.5061/dryad.q573n5tns
title: Exploring the macroevolutionary signature of asymmetric inheritance at speciation

description: Popular comparative phylogenetic models such as Brownian Motion,
 Ornstein-Ulhenbeck, and their extensions, assume that, at speciation, a
 trait value is inherited identically by two descendant species. This
 assumption contrasts with models of speciation at a micro-evolutionary
 scale where descendants’ phenotypic distributions are sub-samples of the
 ancestral distribution. Different speciation mechanisms can lead to a
 displacement of the ancestral phenotypic mean among descendants and an
 asymmetric inheritance of the ancestral phenotypic variance. In contrast,
 even macro-evolutionary models that account for intraspecific variance
 assume symmetrically conserved inheritance of ancestral phenotypic
 distribution at speciation. Here we develop an Asymmetric Brownian Motion
 model (ABM) that relaxes the assumption of symmetric and conserved
 inheritance of the ancestral distribution at the time of speciation. The
 ABM jointly models the evolution of both intra- and inter-specific
 phenotypic variation. It also infers the mode of phenotypic inheritance at
 speciation, which can range from a symmetric and conserved inheritance,
 where descendants inherit the ancestral distribution, to an asymmetric and
 displaced inheritance, where descendants inherit divergent phenotypic
 means and variances. To demonstrate this model, we analyze the evolution
 of beak morphology in Darwin finches, finding evidence of displacement at
 speciation. The ABM model helps to bridge micro- and macro-evolutionary
 models of trait evolution by providing a more robust framework for testing
 the effects of ecological speciation, character displacement, and niche
 partitioning on trait evolution at the macro-evolutionary scale.
description: # Exploring the macroevolutionary signature of asymmetric inheritance at
 speciation --- This dataset contains what is needed to reproduce the
 application of the ABM model on the Coerebinae dataset. ## Description of
 the Data and file structure Data/Coerebinae.csv: Trait dataset in a .csv
 format. This file contains individual measurements of 4 beak traits as
 well as information about the measured individual (Species name, specimen
 ring number, sex, and whether the individual was a juvenile or not). Bill
 total culmen (cm) refers to the length of the upper part of the beak from
 the tip to the skull. Bill nares (cm) refers to the length of the upper
 part of the beak from the tip to the nares. Bill width (cm) refers to the
 width of the upper part of the beak at the nares. Bill depth (cm) refers
 to the height of the beak at the nares. Missing data is marked as NA.
 Data/Coerebinae.tre. Phylogenetic tree file in Newick format with branch
 lengths representing divergence time in my. Scripts/Analysis_thraupidae.R:
 to run the analyses in R Scripts/mcmc_ADIM.R: script with the
 implementation of the ABM model. Scripts/sim_data_ABM.R can be used to
 reproduce the simulations. The model can then be run with the function
 mcmc_ADIM() and the tuning provided in the manuscript. ## Sharing/Access
 Information The data is derived from Reaney, A. M., Y. Bouchenak-Khelladi,
 J. A. Tobias, and A. Abzhanov. 2020. Ecological and morphological
 determinants of evolutionary diversification in Darwin’s finches and their
 relatives. *Ecology and Evolution* 10:14020–14032. The scripts are
 original. The ABM model is maintained and developed further in the
 repository
 [https://github.com/theogab/ABM](https://github.com/theogab/ABM)