DOI: 10.5061/dryad.4xgxd25mr
title: Experimental evolution reveals trade-offs between sexual selection and heat tolerance in Drosophila prolongata

description: Sexual selection promotes traits that enhance mating or fertilization
 success, but these traits can be very costly under harsh environmental
 conditions. The extent to which differential investment in costly traits
 under varying intensities of sexual selection is related to their
 susceptibility to environmental stress remains unclear. This study
 explored how experimental evolution under different operational sex ratios
 (OSRs) shapes traits and reproductive success of male Drosophila
 prolongata, and how developmental and/or adult heat stress affect the
 expression of these traits. We found males from even and slightly
 male-biased OSRs to be larger and display greater reduction in body size
 under developmental heat stress, suggesting pre-mating sexual selection on
 body size and condition-dependent thermal sensitivity. These populations
 also exhibited consistently high mating and fertilization success across
 temperatures, potentially indicating selection for robust phenotypes with
 ‘good genes’ that perform well regardless of temperature. Conversely,
 males from strongly male-biased OSR populations experienced more
 pronounced decline in sperm competitiveness following exposure to
 developmental or adult heat stress. These results highlight how
 environmental stressors differentially impact populations, shaped by
 varying strengths of pre- and post-mating sexual selection. These observed
 patterns suggest potential interactions between past selection and the
 ability to adapt to changing environments.
description: # Experimental evolution reveals trade-offs between sexual selection and
 heat tolerance in Drosophila prolongata
 [https://doi.org/10.5061/dryad.4xgxd25mr](https://doi.org/10.5061/dryad.4xgxd25mr) ## Description of the data and file structure ### Files and variables The data corresponds to the experiment described in the paper. These are the explanations for the columns in the data set: * **uniqueID**: unique identifier for each individual male * **Block**: Refers to the starting day of the mating experiment (A-F) * **Line:** Identifier of the replicate population * **DevTemp:** Developmental temperature treatment: Low or High (L or H) * **AdTemp:** Adult heat exposure treatment: Low or High (L or H) * **Mated_on:** date on which the mating occurred, if NA -&gt; no mating, thus many of the other variables missing due to not having mated * **start_time:** start time of mating * **end_time:** end time of mating * **first*_*check:** "no" if there was no larval development after the first mating * **ver_off:** number of* vermillion* offspring --&gt; from first male * **wt_off:** number of wild type offspring --&gt; from second male * **P2:** second male paternity (untransformed) * **exclude:** 1 if needs to be excluded (i.e., because no larval development after first mating and ver_off = 0 --&gt; unsuccessful first mating; 0 not excluded * **total_female_offspring:** number of female offspring * **thorax:** thorax length as measured under stereoscope (divide by 4 for mm) * **testis_area:** area of both testes combined in pixel (divide by 196.6^2 for mm^2) * **time_frozen:** time of freezing after mating (for testes replenishment): 2dl = 2 days later, dom = day of mating * **deformed:** number of deformed testes: 0, 1 or 2 * **intact_dissection:** whether dissection led to clean result --&gt; those with 0 excluded for testes analysis * **WL:** Wing length in pixel * **WW:** Wing width in pixel * **FLL:** Foreleg length in pixel * **FLL_mm:** Foreleg length in mm * **Tibia_A_sqmm:** Tibia area in mm^2 * **Femur_A_sqmm:** Femur area in mm^2 NAs are data points that are "not available", e.g., due to males not having mated, we did not get P2 data and did not measure testes size.