DOI: 10.5061/dryad.0r75421
title: Data from: Evolution, not transgenerational plasticity, explains the adaptive divergence of acorn ant thermal tolerance across an urban-rural temperature cline

description: Although studies increasingly disentangle phenotypic plasticity from
 evolutionary responses to environmental change, few test for
 transgenerational plasticity in this context. Here, we evaluate if
 phenotypic divergence of acorn ants in response to urbanization is driven
 by transgenerational plasticity rather than evolution. F2 generation
 worker ants (offspring of lab-born queens) exhibited similar divergence
 among urban and rural populations as field-born worker ants suggesting
 that evolutionary divergence rather than transgenerational plasticity was
 primarily responsible for shifts towards higher heat tolerance and
 diminished cold tolerance in urban acorn ants. Hybrid offspring from
 matings between urban and rural populations also indicated that
 evolutionary divergence was likely the primary mechanism underlying
 population differences in thermal tolerance. Specifically, thermal
 tolerance traits were not inherited either maternally or paternally in the
 hybrid pairings as would be expected for strong parental or grandparental
 effects mediated through a single sex. Urban-rural hybrid offspring
 provided further insight into the genetic architecture of thermal
 adaptation. Heat tolerance of hybrids more resembled the urban-urban pure
 type, whereas cold tolerance of hybrids more resembled the rural-rural
 pure type. As a consequence, thermal tolerance traits in this system
 appear to be influenced by dominance rather than being purely additive
 traits, and heat and cold tolerance might be determined by separate genes.
 Though transgenerational plasticity does not appear to explain divergence
 of acorn ant thermal tolerance, its role in divergence of other traits and
 across other urbanization gradients merits further study.
description: F2_CTmax_CTminThis dataset contains 5 columns, including “colonyID”, “date.tt”, “thermal.tolerance.trait”, “thermal.tolerance”, and “cross”. Each row of the dataset represents the response of an individual worker acorn ant. colonyID – a unique identifier for each acorn ant colony; multiple individual workers were tested from the same colony. date.tt – the date (month/day/year) that the thermal tolerance assessment was conducted. thermal.tolerance.trait – a categorical variable describing whether the critical thermal minimum (ctmin) or critical thermal maximum (ctmax) was assessed on the individual worker ant. thermal.tolerance – a continuous numeric value describing either the ctmax or ctmin. Values are presented in units of degrees Celsius. cross – a categorical variable describing the type of cross used to generate the F2 acorn ant workers. This variable has 4 levels, including “rur-rur” which describes a cross where both parents are from rural populations; “urb-urb” which describes a cross where both parents are from urban populations; “rur-urb” which describes a cross where the mother was from a rural population and the father from an urban population; and “urb-rur” which describes a cross where the mother was from an urban population and the father was from a rural population.Field_versus_F2_CTmaxThis dataset contains 4 columns, including “colonyID”, “ctmax”, “generation”, and “population”. Each row of the dataset represents the response of an individual worker acorn ant. colonyID – a unique identifier for each acorn ant colony; multiple individual workers were tested from the same colony. ctmax – a continuous numeric variable describing the value for the critical thermal maximum in degrees Celsius. generation – a categorical variable describing whether the data come from the field-caught generation or the F2 (lab-born) generation. population – a categorical variable describing whether the ants originated from a rural or an urban site.Field_versus_F2_CTminThis dataset contains 4 columns, including “colonyID”, “ctmax”, “generation”, and “population”. Each row of the dataset represents the response of an individual worker acorn ant. colonyID – a unique identifier for each acorn ant colony; multiple individual workers were tested from the same colony. ctmin – a continuous numeric variable describing the value for the critical thermal minimum in degrees Celsius. generation – a categorical variable describing whether the data come from the field-caught generation or the F2 (lab-born) generation. population – a categorical variable describing whether the ants originated from a rural or an urban site.