Genetic Variant 7R Has Been Identified as Potential "Explorer" Gene

While humans have made many notable strides in evolutionary differences between our fellow mammals – opposable thumbs, brain size and development, advanced language, etc – one notable stride has been gaining the attention of evolutionary biologists, neurologists, anthropologists, and geneticists alike. The expansion and exploration of humanity has fallen under the microscope and the research in this area is ever-growing. As reported by none other than National Geographic (who better?), multiple fields of scientists are examining human exploration, including geneticists. In recent studies, geneticists have been examining the effects of a variation on the DRD4 gene, a gene which influences dopamine, an important neurotransmitter in regards to learning, rewards, excitement, and pleasure. The variant in question, DRD4-7R, has been linked to Attention Deficit Hyperactivity Disorder (ADHD), and is starting to get linked to the exploratory tendency of human nature. In a broad sense, human studies have correlated the presence of the 7R variation to restlessness, curiosity, and higher inclination towards adventure and change. In a larger study  conducted by the University of California, the variant 7R was found more commonly in individuals whose ancestors were highly migratory than those who hailed from more sedentary populations. Other studies have found R7 to be more common in individuals whose ancestors had longer tracks of migration, individuals in modern-day migratory groups who are more physically fit and well-nourished when migrating often as opposed to poorly-nourished individuals in settled villages, and even more common in individuals who have lived to old age and exercised well during their lifetime (both in humans and mice) . While multiple studies do come to the conclusion that there is a correlation of the variant in individuals whose ancestors travel and who benefit well from enriching environments and movement in their lifetime, most professionals agree that human exploration, while unique even among hominids (not even Neanderthals were known to move far from their established territories) , cannot be placed solely onto a single gene. Humans are the only mammal known to explore beyond established territories without the need to do so (i.e. depleted resources, following prey, etc.), but there have been a lot of physical adaptations that have led to this unique trend. The change from quadrupedal to bipedal movement allowed humans to expand their territorial range and increase their endurance; the expansion of the brain and the delay in maturation has allowed for the increase in creative thinking as well as intellect that lead to innovative tools and understanding of scenario-based potential outcomes; the rather un-matched dexterity of human hands allowed the human imagination to expand and build tools to aid in travel. While the R7 gene may correlate to hyperactivity and perhaps to the urge to move and maybe even travel, there are many factors that have led to the expansion and exploration that is inherent in humanity.