Nature and nurture: Human brains evolved to be more responsive to environmental influences (Phys.org):
“Chimpanzees are our closest living relatives, but what is it about the human brain that makes us so different? Researchers at the George Washington University may have unearthed another piece of the puzzle. In a study published on Nov. 16, scientists discovered that human brains exhibit more plasticity, propensity to be modeled by the environment, than chimpanzee brains and that this may have accounted for part of human evolution…
“We found that the anatomy of the chimpanzee brain is more strongly controlled by genes than that of human brains, suggesting that the human brain is extensively shaped by its environment no matter its genetics,” said Aida Gómez-Robles, postdoctoral scientist at the GW Center for the Advanced Study of Human Paleobiology and lead author on the paper. “So while genetics determined human and chimpanzee brain size, it isn’t as much of a factor for human cerebral organization as it is for chimpanzees.”
Study: Relaxed genetic control of cortical organization in human brains compared with chimpanzees (PNAS)
- From the abstract: Despite decades of research, we still have a very incomplete understanding of what is special about the human brain compared with the brains of our closest fossil and living relatives. Parsing the genetic versus environmental factors that govern the structure of the cerebral cortex in humans and chimpanzees may shed light on the evolution of behavioral flexibility in the human lineage. We show that the morphology of the human cerebral cortex is substantially less genetically heritable than in chimpanzees and therefore is more responsive to molding by environmental influences. This anatomical property of increased plasticity, which is likely related to the human pattern of development, may underlie our species’ capacity for cultural evolution.