Interplay between genes and the environment has been pondered at least since the phrase "nature versus nurture" was coined in the mid-1800s.
But until the arrival of modern genomic sequencing tools, it was hard to measure the extent that the environment had on a species' genetic makeup.
Now, researchers with the Virginia Bioinformatics Institute at Virginia Tech studying fruit flies that live on opposite slopes of a unique natural environment known as "Evolution Canyon" show that even with migration, cross-breeding, and sometimes the obliteration of the populations, the driving force in the gene pool is largely the environment.
The discovery in this week's Proceedings of the National Academy of Sciences shows that the animals genetically adapt depending on whether they live on the drier, hotter side of the canyon, or the more humid, cooler side.
"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, an associate professor at the Virginia Bioinformatics Institute. "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 two slopes of Evolution Canyon, which is located at Mount Carmel, Israel, are little more than two football fields apart at their bases, but the south-facing slope is tropical and may receive eight times as much sun, while the north-facing slope is more like a European forest.
Knowledge that climatic and environmental factors seem to exert a significant effect on the fruit-fly genome in spite of migration or repopulations adds to current understanding of the biodiversity, resilience, and ability of a species to adapt to rapid climate change.
The native fruit fly in question — Drosophila melanogaster — is a well-studied laboratory animal and the source of the world's knowledge of how genetic information is packaged in chromosomes.
More than 65 percent of disease-causing genes in humans are believed to have functional counterparts in the fly, including many genes involved in certain cancers, Alzheimer's and Parkinson's diseases, heart disease, and other medical conditions.
Researchers used a technique known as whole genome sequencing to characterize the complete set of DNA in the total population of the fruit flies, noting differences in the genetic makeup between the populations on the opposing slopes.
The international team, which included scientists from the Institute of Evolution at Haifa University, the University of British Columbia in Vancouver, and Memorial Sloan-Kettering Cancer Center in New York, discovered 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, researchers discovered that genetic changes were accumulating in chromosomal "islands" in the north-facing-slope flies, suggesting adaptive gene mutations would sweep through the population, given time.
Migration of flies between the slopes was confirmed by capturing and marking them 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," Michalak said. "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 research confirms that natural selection — the process in nature where organisms genetically adapt to their surroundings — is a powerful influence in the canyon.
"It is nice to see the molecular work finally completed, and that the molecular signal confirms the phenotypic data: There is divergence between the two slopes," said Marta L. Wayne, a professor of biology at the University of Florida and a member of the UF Genetics Institute, who was not involved in the research. "This is interesting because the slopes are close enough that we know animals travel between them, yet selection is so strong that there are differences between animals on the two slopes. This is really strong natural selection."
The research was supported by the United States-Israel Binational Science Foundation.
John Pastor | EurekAlert!
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Trade Fair News
16.01.2017 | Automotive Engineering
16.01.2017 | Life Sciences