The Evolutionary Tale of Cannibalism, Genetic Resistance, and a Mysterious Brain Disease
Photo by Vika Jordanov on Unsplash
In a remote region of Papua New Guinea, the narrative of a tribe known as the Fore people takes a turn that is both tragic and fascinating. Their practice of cannibalism, a ritual act that involved consuming human brains, introduced them to a deadly brain disease known as kuru. But in a twist, nature seems to have favored some members of the tribe, as they now carry a gene that appears to not only protect against kuru but other prion diseases, like mad cow. This development offers researchers a new vista into understanding these fatal brain conditions and possibly unlocking treatments for them.
The Historical Context: The Fore People and the Kuru Epidemic
For the Fore people, consuming the human brain was part of a funeral ritual. However, as the 20th century began, an unforeseen consequence of this practice emerged. Members of the tribe started showing signs of kuru, a neurological ailment induced by infectious prions. These are proteins that misfold, leading to the formation of brain lesions. As a result, the tribe experienced a devastating epidemic of kuru, which at its peak in the 1950s, claimed up to 2 percent of the tribe annually.
By the late 1950s, the tribe had ceased the practice of cannibalism, leading to a gradual decline in kuru occurrences. However, the nature of the disease meant that it could lay dormant for years before manifesting, hence cases persisted for subsequent decades.
A Genetic Resistance: The V127 Mutation
Fast-forward to recent times, and researchers made a groundbreaking discovery. They found that some individuals who lived through the kuru epidemic have a genetic mutation termed V127, which was conspicuously absent in those who succumbed to kuru. This hinted that the V127 mutation might be a protective shield against the disease.
Eager to test this hypothesis, in a recent study, mice were genetically modified to possess the V127 mutation. These mice were then exposed to infectious prions. The outcomes were revealing: Mice with a single copy of the V127 mutation showed resistance to kuru and the related Creutzfeldt-Jakob disease. Those with two V127 copies were resistant to these and also to the variant Creutzfeldt-Jakob disease, sometimes dubbed the “human version of mad cow disease.”
Had the Fore people continued with the cannibalistic rituals, the research indicates that kuru might have further spread, but eventually, individuals resistant to kuru, due to the V127 mutation, might have repopulated the region.
The Bigger Picture: Evolution at Play
It’s vital to clarify that the cannibalistic rituals weren’t the direct cause of the V127 mutation’s development. The mutation likely existed in the community prior to the kuru outbreak. However, those with the mutation had a distinct survival advantage when the epidemic struck, leading to its proliferation within the population. This phenomenon, where genetic traits are selected due to advantages they confer, underpins the principles of evolution.
Dr. John Collinge, the lead author of the study and a distinguished professor at University College London, remarked, “This event highlights a powerful instance of Darwinian evolution in humans; an epidemic that favored a particular genetic alteration, granting full protection against a lethal neurological disorder.”
Understanding this genetic mutation and its preventative action against prion protein misfolding can potentially shed light on new preventive measures against prion diseases.
In the intricate dance between culture, genetics, and nature, the tale of the Fore people serves as a stark reminder of the unforeseen consequences of our practices and the unpredictable ways in which nature can respond.
Link to a about it : https://tourtravelsvibes.blogspot.com/
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