In case anyone wanted to know why Neanderthals went extinct, know that scientists at University of California, San Diego are working on finding the answer. By growing Neanderthal brains in petri dishes, which will later be placed inside crab-like robots, scientists believe that by studying the robot’s behavior, they’ll gain a new understanding of why the Neanderthals were wiped from the surface of the Earth.
The process started with human pluripotent stem cells, which were edited using a gene editing tool called CRISPR. Through the process, the stem cells became “Neanderthalized,” according to Live Science. This is done by using genetic information extracted from fossils. After six to eight months in a petri dish and an “in-house process,” the cells grow into tiny brains measuring about 0.2 inches. The brains don’t have a blood supply, so they stop growing when they reach that size.
As if that’s not enough, the brains will be hooked up to robots. From there, scientists will observe its behavior and learning patterns to gain knowledge of the Neanderthal brains. Study leader Alysson Muotri elaborated.
“By doing this systematically, we will learn what are the genetic alterations that made us uniquely human and why they were positively selected.”
Muotri also describes her motivation behind the project, saying that “Neanderthals are fascinating because they shared Earth with us and there is now genetic evidence we actually bred with them.”
The process of growing brains in petri dishes is not new. According to Scientific American, scientists have grown human brains before. The brains only grew to be about the size of lentils, and they were grown inside mice skulls. In this case, the mice gave the brain enough blood supply and nutrients to allow it to maintain its status for months.
“In our hands, the organoids stop growing around five weeks,” Fred Gage, the study’s leader said. “It’s a function of size rather than time. We see some cell death even in the edge of the organoids starting at 10 weeks, which becomes dramatic over time. This is an obvious hurdle for longtime study.”
And just like in the experiment with Neanderthal brains and robots, the mice were compared side by side. The mice with human brains and mice with regular mice brains appeared to have some differences. For example, the mice with human brains apparently made fewer mistakes in a maze, but that was only on the first day of testing.
As technology advances and more studies are conducted with animals and human brains, both the scientific and general community ought to consider the ethical and scientific implications of these groundbreaking studies.