In a laboratory in Germany, an advance that seems like science fiction has been achieved: they are cultivating human brain cells with Neanderthal characteristics. These cells, which form synaptic connections and emit electrical signals, seek to replicate how the brain of a living Neanderthal would have worked. Led by geneticist John Krausethe experiment is developed in the book that he published together with the journalist Thomas Trappe: Hybris.
The central objective is to understand the genetic differences that separate Homo sapiens from Homo neanderthalensis, and how these differences could have determined the fate of both species. Only about 90 genetic variations distinguish modern humans from Neanderthals, a surprisingly low number considering that the human genome contains approximately 20,000 genes.
These differences, although limited, could be key to understanding why Neanderthals became extinct about 40,000 years ago, while Sapiens not only survived, but came to dominate the planet. For the authors of Hybristhese genetic differences could contain crucial clues to confront humanity’s current challenges, such as the climate crisis and biodiversity loss.
The German experiment focuses on the creation of brain organoids, rudimentary structures that mimic the development of the human brain. Although these organoids are the size of a lentil and lack the ability to think or feel, they represent a significant technical advance. However, the authors acknowledge that to fully understand the implications of these genetic differences it would be necessary to construct complete organs or even Neanderthal individuals, something they consider ethically unacceptable.
Laura Spinney wrote in The Guardian an interesting review: “The authors state that there is no evidence that Neanderthals created art, which, if true, could imply that they had less capacity for abstract thought than we do. Not everyone would agree with this, but most would admit that Neanderthals differed from us linguistically and cognitively. The question is: can we take advantage of these differences to contain our greedy impulses before it is too late? “Can we mobilize culture to overcome biology?”
The book also offers a comprehensive review of human evolution, a field that has undergone a revolution in the last two decades thanks to technology that allows DNA to be extracted and analyzed from ancient fossils. This technology has revealed that most branches of the human family were evolutionary dead ends, and that only sapiens managed to survive. But what gave them this advantage? Krause and Trappe put forward several hypotheses, from the ability to build complex social networks to a risky and visionary approach to exploring new territories.
A prominent example of this human expansion is the colonization of Austronesia, where the sapiens’ ancestors set sail from Taiwan about 5,000 years ago, bringing with them animals, seeds, and children, but with no guarantee of finding new habitable lands. This drive to explore and colonize eventually led modern humans to occupy every corner of the planet, and now, to look towards the Moon and Mars as next destinations.
However, the authors warn that this expansionary impulse has not always been sustainable. According to the book, an emblematic case is that of Rapa Nui (Easter Island), where it has long been argued that the original inhabitants exhausted the natural resources, leading to their collapse. However, recent research questions this narrative, suggesting that the islanders lived sustainably until the arrival of Europeans in the 19th century.
This example, according to Krause and Trappe, underscores the ability of sapiens to adapt culturally, an ability that ultimately resides in our genes. The book also argues that the transformation of sapiens into an existential threat to themselves occurred in the 20th century, when exponential population growth, technological advances and climate change accelerated biodiversity loss.
