(SOMATÓRIA)
RESTLESS GENES
Once modern humans began their migration out of Africa some 60,000 years ago, they kept going until they had spread to all corners of the Earth. How far and fast they went depended on climate, the pressures of population, and the invention of boats and other technologies. Less tangible qualities also sped their footsteps: imagination, adaptability, and an innate curiosity about what lay over the next hill.
If an urge to explore rises in us innately, perhaps its foundation lies within our genome. In fact there is a mutation that pops up frequently in discussions about exploration: a variant of a gene called DRD4, which helps control dopamine, a chemical brain messenger important in learning and reward. Researchers have repeatedly tied the variant, known as DRD4-7R and carried by roughly 20 percent of all humans, to curiosity and restlessness. Dozens of human studies have found that 7R makes people more likely to take risks; explore new places, ideas, foods, relationships, drugs, or sexual opportunities; and generally embrace movement, change and adventure.
Most provocatively, several studies tie 7R to human migration. The first large genetic study to do so, led by Chuansheng Chen of the University of California, Irvine in 1999, found 7R more common in present-day migratory cultures than in settled ones. A larger, more statistically rigorous 2011 study supported this, finding that 7R, along with another variant named 2R, tends to be found more frequently than you would expect by chance in populations whose ancestors migrated longer distances after they moved out of Africa.
Adaptado de: Restless Genes, de David Dobbs. National Geographic – January 2013.
Com base no texto como um todo, assinale o que for correto.
01) A necessidade de explorar o que o ser humano tem, pode ter origem genética.
02) As variantes do gene DRD4, o 7R e o 2R são frequentemente encontradas em populações cujos ancestrais percorreram maiores distâncias a partir da África.
04) Cerca de 20% da humanidade carrega o gene DRD4-7R.
08) Estudos mostram que portadores da variante 7R costumam gostar de correr riscos.