image: Comparison between Homo Sapiens and Homo Neanderthalensis view more
Credit: University of Granada
Creativity--the "secret weapon" of Homo sapiens--constituted a major advantage over Neanderthals and played an important role in the survival of the human species. This is the finding of an international team of scientists, led by the University of Granada (UGR), which has identified for the first time a series of 267 genes linked to creativity that differentiate Homo sapiens from Neanderthals.
This important scientific finding, published today in the prestigious journal Molecular Psychiatry (Nature), suggests that it was these genetic differences linked to creativity that enabled Homo sapiens to eventually replace Neanderthals. It was creativity that gave Homo sapiens the edge, above and beyond the purely cognitive level, by facilitating superior adaptation to the environment compared to that of now-extinct hominids and providing greater resilience to ageing, injury, and disease.
The research team comprises Igor Zwir, Coral del Val, Rocío Romero, Javier Arnedo, and Alberto Mesa from the UGR's Department of Computer Science and Artificial Intelligence, the Andalusian Research Institute in Data Science and Computational Intelligence (DaSCI), and the Biohealth Research Institute in Granada (ibs.GRANADA), together with Robert Cloninger of Washington University in St. Louis and colleagues from the Young Finns Study (Finland), the American Museum of Natural History (New York), and the Menninger Clinic (Houston, Texas).
Their findings are the result of an interdisciplinary study that brings together Artificial Intelligence (AI), Molecular Genetics, Neurosciences, Psychology, and Anthropology. This is the fifth consecutive paper published by this research team in one of the most prestigious scientific journals in the area concerned with the human personality.
The 267 genes identified by these scientists as being unique to Homo sapiens are part of a larger group of 972 that are linked to personality in healthy adults and were also discovered by the same authors. In previous studies, they showed that these 972 genes are organized into three dissociable brain networks of personality traits that are responsible for learning and memory.
Evolution of genetic networks
"These networks evolved in stages. The most primitive network emerged among monkeys and apes about 40 million years ago, and is responsible for emotional reactivity--in other words, it regulates impulses, the learning of habits, social attachment, and conflict-resolution," explain the UGR researchers. Less than 2 million years ago, the second network emerged. This regulates intentional self-control: self-direction and social cooperation for mutual benefit. Finally, about 100,000 years ago, the network relating to creative self-awareness emerged.
The new study that is published this week reveals that the genes of the oldest network, that of emotional reactivity, were almost identical in Homo sapiens, Neanderthals, and chimpanzees. By contrast, the genes linked to self-control and self-awareness among Neanderthals were "halfway between" those of chimpanzees and Homo sapiens.
Most of these 267 genes that distinguish modern humans from Neanderthals and chimpanzees are RNA regulatory genes and not protein-coding genes. Almost all of the latter are the same across all three species, and this research shows that what distinguishes them is the regulation of expression of their proteins by genes found exclusively in humans. Using genetic markers, gene-expression data, and integrated brain magnetic resonance imaging based on AI techniques, the scientists were able to identify the regions of the brain in which those genes (and those with which they interacted) were overexpressed. These regions are involved in human self-awareness and creativity, and include the regions that are strongly associated with human well-being and that appeared relatively recently, phylogenetically speaking.
Superior resilience
Furthermore, the authors continue, "thanks to these genes, Homo sapiens enjoyed greater physical fitness than now-extinct hominids, providing them with a superior level of resilience to ageing, injury, and disease." Using genetic data, the researchers were able to estimate from these genes that the adaptability and well-being of Neanderthals were approximately 60%-70% those of Homo sapiens, meaning that the difference between them in terms of physical fitness was significant.
The findings have far-reaching implications in our understanding of the factors that ultimately enabled Homo sapiens to replace Neanderthals and other species in the geologically-recent past. The authors hypothesize that creativity may have given Homo sapiens selective advantages beyond the purely cognitive realm.
"Living longer and healthier lives may have prolonged the period of learning associated with youth and adolescence, which would facilitate the accumulation of knowledge. This is a remarkable characteristic of behaviourally-modern humans and an important factor in economic and social success," explain the researchers. Creativity may have encouraged cooperation between individuals in a bid to encourage success among their descendants and their community. This would have set the stage for technological innovation, behavioural flexibility, and openness to exploration, all of which were necessary for Homo sapiens to spread across the world more successfully than other human lineages.
In the five studies published to date by these researchers in Nature, they have found--and verified using multiple data sources--that human behaviour is neither entirely fixed nor solely determined by our genes, but rather is influenced also by multiple interactions with the environment. "We have the capacity to learn and adapt in light of our experience, even to the extent of modifying the expression of our genes. Human creativity, prosociality, and healthy longevity emerged as a response to the need to adapt to the harsh and diverse conditions that reigned between 400,000 and 100,000 years ago," note the UGR researchers.
This study is just one example of how the use of AI techniques and the entirely bias-free treatment of data can help to solve many puzzles about the evolution of human beings. The results obtained pave the way to the development of new lines of research that can ultimately promote human well-being and help us to adapt creatively in order to overcome critical situations.
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Journal
Molecular Psychiatry