DOI: 10.5061/dryad.4bk56qr
title: Data from: Evolution of thermal tolerance and its fitness consequences: parallel and non-parallel responses to urban heat islands across three cities

description: The question of parallel evolution—what causes it, and how common it
 is—has long captured the interest of evolutionary biologists. Widespread
 urban development over the last century has driven rapid evolutionary
 responses on contemporary timescales, presenting a unique opportunity to
 test the predictability and parallelism of evolutionary change. Here we
 examine rapid urban evolution in an acorn-dwelling ant species, focusing
 on the urban heat island signal and the ant’s tolerance of these altered
 urban temperature regimes. Using a common-garden experimental design with
 acorn ant colonies collected from urban and rural populations in three
 cities and reared under five temperature treatments in the laboratory, we
 assessed plastic and evolutionary shifts in the heat and cold tolerance of
 F1 offspring worker ants. In two of three cities, we found evolved losses
 of cold tolerance, and compression of thermal tolerance breadth. Results
 for heat tolerance were more complex: in one city, we found evidence of
 simple evolved shifts in heat tolerance in urban populations, though in
 another, the difference in urban and rural population heat tolerance
 depended on laboratory rearing temperature, and only became weakly
 apparent at the warmest rearing temperatures. The shifts in tolerance
 appeared to be adaptive, as our analysis of the fitness consequences of
 warming revealed that while urban populations produced more sexual
 reproductives under warmer laboratory rearing temperatures, rural
 populations produced fewer. Patterns of natural selection on thermal
 tolerances supported our findings of fitness tradeoffs and local
 adaptation across urban and rural acorn ant populations, as selection on
 thermal tolerance acted in opposite directions between the warmest and
 coldest rearing temperatures. Our study provides mixed support for
 parallel evolution of thermal tolerance under urban temperature rise.
description: Worker Ant
 CTminCTmin = critical thermal
 minimum in degrees Celsius; ColonyID = identity of the colony from which
 the individual worker ants were tested; habitat.designation = whether the
 habitat is "urban" or "rural"; longitude = the decimal
 degrees longitude of the collection site of the colony; latitude = the
 decimal degrees latitude of the collection site of the colony; treatment =
 the temperature treatment under which the colonies were reared in the
 laboratory, including 21, 23, 25, 27, or 29 degrees Celsius; city = the
 urbanization cline from which the colonies were obtained, including
 "Knx" (Knoxville, TN), "Cin" (Cincinnati, OH),
 "Cle" (Cleveland, OH)WorkerCTmin.csvWorker Ant CTmaxCTmax = critical thermal maximum in degrees Celsius; ColonyID = identity of the colony from which the individual worker ants were tested; habitat.designation = whether the habitat is "urban" or "rural"; longitude = the decimal degrees longitude of the collection site of the colony; latitude = the decimal degrees latitude of the collection site of the colony; treatment = the temperature treatment under which the colonies were reared in the laboratory, including 21, 23, 25, 27, or 29 degrees Celsius; city = the urbanization cline from which the colonies were obtained, including "Knx" (Knoxville, TN), "Cin" (Cincinnati, OH), "Cle" (Cleveland, OH)WorkerCTmax.csvQueen Ant CTminCTmin = critical thermal minimum in degrees Celsius; ColonyID = identity of the colony from which the individual queen ants were tested; habitat.designation = whether the habitat is "urban" or "rural"; longitude = the decimal degrees longitude of the collection site of the colony; latitude = the decimal degrees latitude of the collection site of the colony; treatment = the temperature treatment under which the colonies were reared in the laboratory, including 21, 23, 25, 27, or 29 degrees Celsius; city = the urbanization cline from which the colonies were obtained, including "Knx" (Knoxville, TN), "Cin" (Cincinnati, OH), "Cle" (Cleveland, OH)QueenCTmin.csvQueen Ant CTmaxCTmax = critical thermal maximum in degrees Celsius; ColonyID = identity of the colony from which the individual queen ants were tested; habitat.designation = whether the habitat is "urban" or "rural"; longitude = the decimal degrees longitude of the collection site of the colony; latitude = the decimal degrees latitude of the collection site of the colony; treatment = the temperature treatment under which the colonies were reared in the laboratory, including 21, 23, 25, 27, or 29 degrees Celsius; city = the urbanization cline from which the colonies were obtained, including "Knx" (Knoxville, TN), "Cin" (Cincinnati, OH), "Cle" (Cleveland, OH)QueenCTmax.csvAlate productionalates = number of alates (reproductive ants) produced over the course of the experiment; ColonyID = identity of the colony from which the number of alates produced was assessed; habitat.designation = whether the habitat is "urban" or "rural"; treatment = the temperature treatment under which the colonies were reared in the laboratory, including 21, 23, 25, 27, or 29 degrees Celsius; city = the urbanization cline from which the colonies were obtained, including "Knx" (Knoxville, TN), "Cin" (Cincinnati, OH), "Cle" (Cleveland, OH)AlateCounts.csv