Serious Neurological Condition May Be Linked to Neanderthal Genes

Crossing between anatomically modern Homo sapiens And the Neanderthals thousands of years ago can be responsible for the malformation of Chiari, type 1, a serious and sometimes fatal neurological condition estimated as having an impact up to 1% of people today.

In 2013, scientists hypothesized that individuals develop a type 1 chiari malformation because some of their genes coding for cranial development derived from three extincts Homo Species that have a smaller base than what is typical for modern humans: Homo erectus,, Homo heidelbergensisAnd Homo neanderthalensis; Dive and al. used 3D data and geometric morphometry to assess this hypothesis. Image credit: Neanderthal Museum.

Type 1 chiari malformation occurs when the back of a human skull is too small to hold the brain correctly, part of the basis of the brain to blow up the skull and in the spinal channel.

This can lead to pinching the herni part of the brain, causing symptoms such as headaches, neck pain, dizziness and, in serious cases, death, if too much hernia brain.

“In medicine, as in other sciences, the clarification of causal channels is important”, “

“The more clearly it can be of the causal chain, which leads to a medical condition, the more you can be able to manage, even solve the condition.”

“The hypothesis must be tested further, but our study can mean that we are one more step to obtain a clear understanding of the causal chain which gives rise to the malformation of Chiari.”

In 2010, scientists discovered genetic evidence that the members of our species were maintained with dozens of Neanderthals thousands of years ago.

Living non-Africans have 2 to 5% of Neanderthal DNA which can be retraced to these crossing events.

The idea that type 1 chiari malformation could be the result of other hominin genes entering the pool of human genes by a crossing was initially proposed by the researcher of the Campinas State University, Yvens Barbosa Fernandes.

Because the modern human skull differs in several important ways from those of other homestones, Dr. Fernandes has reasoned, having a skull which is influenced by genes of other species of hominin can be one of the factors that causes malformation.

In a new study, Professor of the University Simon Fraser, Mark Collard, Dr. Kimberly Pomp of the University of the Philippines Diliman and their colleagues, put this theory to test using modern medical imaging technology and advanced statistical formal analysis techniques to compare 3D models of Skulls from living humans, including the old and without chiari -malformation of type 1, Understanding the old and without cherishing of Chiari Maleforation 1, with Homin Fossils, including the old and without chiari malformation type 1, with homin fossils, including the old and without the old. Homo sapiensNeanderthals, Homo heidelbergensisAnd Homo erectus.

They found that people with chiari malformation share more traits of common form with Neanderthals than people without malformation.

Interestingly, all the other fossil skulls were closer to the form of humans without the type 1 chiari malformation, indicating that the results are not due to shared ancestry, but rather support the hypothesis that certain people today have Neanderthal genes which affect their skull shape, and this form of skull results in a gap between the shape of the skull and the shape of the modern human brain.

It is this inadequacy that makes the brain not enough room in the skull, and therefore, the brain is pushed the only hole available, the vertebral canal.

With different populations from around the world with different levels of Neanderthal DNA, the study predicts that certain populations – including those of Europe and Asia – could be more at risk of type 1 chiari malformation than others, although additional research is necessary to confirm it.

“The study of archeology and human evolution is not only interesting,” said Professor Collard.

“It also has the potential to help us understand and, in some cases, to face problems in the present.”

“In this case, we used fossils to help us shed light on a medical condition, but there are many other contemporary problems that archaeological and paleontological data can help us better understand.”

The study was published in the journal Evolution, medicine and public health.

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Kimberly Pump and al. 2025. A test of the archaic Homo Hypothesis of introgression for the malformation of Chiari Type I. Evolution, medicine and public health 13 (1): 154-166; Doi: 10.1093 / EMPH / EOAF009