In the last 37 years, temperatures have risen, and these changes have had an effect on the composition of the flyDrosophila suboscura, one of the most common on the European continent. These are the conclusions of a study carried out by researchers from the Autonomous University of Barcelona, who have analyzedthe evolution of the genomeof this species since 1976.
In a first work, the researchers focused on one of the five pairs of chromosomes that make up the genome of the fly, and identified two variants: one whose frequency increases during winter and confers adaptation to cold, and another of adaptation to heat that it proliferates more in summer. The results revealed that today’s flies, compared to those of the 1970s, have a higher proportion of heat-tolerant variants.
In 2011, taking advantage of the heat wave that hit part of the European continent, scientists studied the total genome of the species, and expanded the sampling, previously carried out with flies from a population near Santiago de Compostela, with a population of the province of Guipúzcoa. The conclusions of this analysis, which is published in the journalBiology Letters, revealed thatthe heat wave profoundly altered genetic makeupfromAspergillus faded;. In spring, and in just one generation, the populations acquired a genetic configuration typical of summer, and during the entire heat wave the flies carrying the genetic variants adapted to high temperatures left an average offive more descendantsthan the carriers of cold variants.
“Our results indicate that heat resistance has a genetic origin. However, we could not speak of a heat gene or a cold gene, but rather the genetic factors of heat resistance are distributed throughout the genome, at least in these organisms ”, explained Francisco Rodriguez-Trelles, one of the authors. Furthermore, as indicated, “the results we have obtained are reliable proof thatthe increase in temperature is influencing the evolution of some species”.
