Environment Drives Genetics in 'Evolution Canyon': Implications for Climate Change

It turns out that the environment has more influence on genetics than we thought--especially when it comes to species in the wild. Scientists have discovered that even with migration, cross-breeding and sometimes the obliteration of populations, the driving force in the gene pool is largely the environment. The findings could have major implications for the results of climate change in the future.

In order to examine how the environment might impact evolution and genes, the researchers examined fruit flies that live on opposite slopes of a unique natural environment known as "Evolution Canyon." Located at Mount Carmel, Israel, the two slopes of the canyon are little more than two football fields apart at their bases. However, the south-facing slope is tropical and may receive eight times as much sun. The north-facing slope is more like a European forest.

"Despite complicating factors, such as likely gene flow between the two populations and changing demographics, the difference in the microclimate in this canyon apparently is so pervasive that it is sufficient to drive the genetic differences," said Pawel Michalak, one of the researchers, in a news release. "We don't have many examples of rapid environmental adaptation to stressful conditions from the field. We can simulate such conditions in a lab, but it is valuable to observe this actually happening in a natural system."

The researchers used whole genome sequencing in order to characterize the complete set of DNA in the total population of the fruit flies. They then noted differences in the genetic makeup between the populations on the opposing slopes. In the end, they found that 572 genes were significantly different in frequency between the populations, corroborating previous observations of differences in heat tolerance, life history and mating behavior. In addition, the researchers confirmed migration between the slopes by capturing and marking the flies with florescence.

"Although we were not correlating genetic change with climate change, we were looking at heat-stress effects, which gives us an indirect understanding relevant to global climate changes," said Michalak in a news release. "We need some good indicators of genomic changes induced by climate changes. People have ways to cope unlike those of other organisms, but stress-resistance mechanisms are well-conserved in nature. The basic question of how organisms adapt to stressful environments is going to be more important in the years ahead. It affects us as a whole."

The findings reveal a little bit more about how the environment can impact species. This, in turn, has major implications for climate change. As our environment shifts, species will be drastically impacted.

The findings are published in the journal Proceedings of the National Academy of Sciences.