Now, a team of European researchers has taken this science to the next level, by developing spots of brain tissue from human stem cells that contain DNA and Neanderthal proteins, in the hope that they will clear up the way whose Neanderthals are related to modern humans.
"We were curious to what extent the Neanderthal genome could be explored if you only had access to the right stem cells from the right people," said Grayson Camp, head of the research group at the Institute for Molecular Ophthalmology and clinic in Basel, Switzerland, and author of a new study.
He said the research was a proof of concept that could potentially help understand the cognitive and other differences between humans and Neanderthals - although it isat a very early stage of research.
Brain, simplified
"We analyzed the genome of each of these individuals for which there are stem cells, and by comparing the reference genome generated by the Pääbo laboratory, we were able to determine which parts were probably derived from Neanderthals and which parts were not. not, "he told me.
"Per individual, there is between 1% and 4% of the genome probably derived from Neanderthals," he explained.
"If you then look at 200 individuals, you end up recovering about 20% of these Neanderthal genes. This means that in total, this stem cell resource contains most of the Neanderthal genes found inside Europeans."
The team then developed brain organoids - 3D spots of brain tissue a few millimeters wide and only visible to the naked eye - from these cells by feeding them in a Petri dish with a growth factor.
Organoids, which can roughly mimic many human organs, can be used to safely test the specific effects of drugs outside the body, which has revolutionized and personalized areas such as cancer treatment.
"Researchers have of course generated and analyzed organoids from human cells before, no one had ever bothered to look at what Neanderthal DNA could do," said Camp.
Proof of concept
Camp wanted to emphasize that these were not "laboratory-grown Neanderthal brains".
"These are human cells, not Neanderthal cells but human cells that naturally contain Neanderthal DNA," said Camp.
"It is totally different from Jurassic Park.It's more about studying the mechanism than trying to recreate something (which no longer exists.) "
In the future, other tissues of body parts could be grown and studied in this way to see how Neanderthal traits could have shaped ours, said Camp.
Likewise, it could potentially be used to create intestinal organoids to examine how sets of enzymes process food, providing information on the Neanderthal diet.
However, given the technical variations in the culture of these cells, the technique can take at least a few years to produce interesting data, said Camp.
"It is difficult to do these experiments properly, as there are not expected to be any major differences: the Neanderthals and the Humans were after all very similar. Furthermore, these cropping systems are not yet optimal, "he said.