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- No evidence for short‐term evolutionary response to a warming environment in DrosophilaPublication . Santos, Marta A.; Carromeu‐Santos, Ana; Quina, Ana; Santos, Mauro; Matos, Margarida; Simões, PedroAdaptive evolution is key in mediating responses to global warming and may sometimes be the only solution for species to survive.Such evolution will expectedly lead to changes in the populations’ thermal reaction norm and improve their ability to cope with stressful conditions. Conversely, evolutionary constraints might limit the adaptive response. Here, we test these expectations by performing a real-time evolution experiment in historically differentiated Drosophila subobscura populations. We address the phenotypic change after nine generations of evolution in a daily fluctuating environment with average constant temperature, or in a warming environment with increasing average and amplitude temperature across generations. Our results showed that (1) evolution under a global warming scenario does not lead to a noticeable change in the thermal response; (2) historical background appears to be affecting responses under the warming environment, particularly at higher temperatures; and (3) thermal reaction norms are trait dependent: although lifelong exposure to low temperature decreases fecundity and productivity but not viability,high temperature causes negative transgenerational effects on productivity and viability, even with high fecundity. These findings in such an emblematic organism for thermal adaptation studies raise concerns about the short-term effciency of adaptive responses to the current rising temperatures.
- Heat-induced female biased sex ratio during development is not mitigated after prolonged thermal selectionPublication . Santos, Marta A.; Antunes, Marta; Grandela, Afonso; Carromeu-Santos, Ana; Quina, Ana; Santos, Mauro; Matos, Margarida; Simões, PedroBackground The negative impacts of climate change on biodiversity are consistently increasing. Developmen‑ tal stages are particularly sensitive in many ectotherms. Moreover, sex-specifc diferences in how organisms cope with thermal stress can produce biased sex ratios upon emergence, with potentially major impacts on population persistence. This is an issue that needs investigation, particularly testing whether thermal selection can alleviate sex ratio distortions in the long-term is a critical but neglected issue. Here, we report an experiment analyzing the sex ratio patterns at diferent developmental temperatures in Drosophila subobscura populations subjected to long-term experimental evolution (~30 generations) under a warming environment. Results We show that exposure to high developmental temperatures consistently promotes sex ratio imbalance upon emergence, with a higher number of female than male ofspring. Furthermore, we found that thermal selec‑ tion resulting from evolution in a warming environment did not alleviate such sex ratio distortions generated by heat stress. Conclusions We demonstrate that heat stress during development can lead to clear sex ratio deviations upon emergence likely because of diferential survival between sexes. In face of these fndings, it is likely that sex ratio deviations of this sort occur in natural populations when facing environmental perturbation. The inability of many insects to avoid thermal shifts during their (more) sessile developmental stages makes this finding particularly troublesome for population subsistence in face of climate warming events.
- Experimental Evolution in a Warming World: The Omics EraPublication . Santos, Marta A.; Carromeu-Santos, Ana; Quina, Ana S; Antunes, Marta; Kristensen, Torsten N; Santos, Mauro; Matos, Margarida; De mendonça fragata almeida, Inês; Simões, PedroA comprehensive understanding of the genetic mechanisms that shape species responses to thermal variation is essential for more accurate predictions of the impacts of climate change on biodiversity. Experimental evolution with high-throughput resequencing approaches (evolve and resequence) is a highly effective tool that has been increasingly employed to elucidate the genetic basis of adaptation. The number of thermal evolve and resequence studies is rising, yet there is a dearth of efforts to integrate this new wealth of knowledge. Here, we review this literature showing how these studies have contributed to increase our understanding on the genetic basis of thermal adaptation. We identify two major trends: highly polygenic basis of thermal adaptation and general lack of consistency in candidate targets of selection between studies. These findings indicate that the adaptive responses to specific environments are rather independent. A review of the literature reveals several gaps in the existing research. Firstly, there is a paucity of studies done with organisms of diverse taxa. Secondly, there is a need to apply more dynamic and ecologically relevant thermal environments. Thirdly, there is a lack of studies that integrate genomic changes with changes in life history and behavioral traits. Addressing these issues would allow a more in-depth understanding of the relationship between genotype and phenotype. We highlight key methodological aspects that can address some of the limitations and omissions identified. These include the need for greater standardization of methodologies and the utilization of new technologies focusing on the integration of genomic and phenotypic variation in the context of thermal adaptation.