The Surprising Truth Behind the Neanderthal Population Crash 110000 Years Ago – Indian Defence Review

Around 110,000 years ago, a genetic bottleneck dramatically reduced Neanderthal diversity, foreshadowing their extinction. This collapse, revealed through fossil and DNA analysis, reshaped their evolutionary path.Neanderthal population, a species that thrived in Eurasia for over 250,000 years, experienced a dramatic decline in genetic diversity around 110,000 years ago. Recent studies indicate that this event—described as a genetic bottleneck—severely reduced their population size, leading to a loss of variability in their physical and genetic traits.While the extinction of Neanderthals around 40,000 years ago is well documented, this earlier population collapse suggests they had already been struggling for survival long before their final disappearance.Researchers analysing both fossil records and DNA evidence have found that this sudden reduction in numbers significantly altered the course of Neanderthal evolution on Earth.For decades, scientists believed that Neanderthals evolved gradually, with relatively stable populations. However, recent research challenges this view, suggesting that their history was far more complex and volatile. Fossils from different periods reveal that early Neanderthals exhibited significant genetic and morphological diversity, meaning they had a broad range of physical traits. This diversity likely helped them adapt to different environments across Europe and Asia.However, something catastrophic happened roughly 110,000 years ago. The diversity that once characterised Neanderthal populations sharply declined, indicating a significant loss of individuals and possibly entire groups.Fossil evidence suggests that between 430,000 and 120,000 years ago, Neanderthal diversity actually increased before suffering a dramatic collapse. This event may have had long-term consequences for their ability to withstand later environmental challenges.To better understand this population collapse, scientists analysed the bony labyrinth—a part of the inner ear responsible for balance and movement—in Neanderthal fossils. This method provides a unique way to study genetic variation when DNA is too degraded for analysis.The findings revealed a clear pattern: earlier Neanderthals, such as those from Krapina, Croatia (120,000–130,000 years old), showed much more variation in their inner ear structures than later, so-called “classic” Neanderthals.This aligns with genetic evidence suggesting a bottleneck event had severely impacted their population. Interestingly, the study also challenges the idea that Neanderthals started with low genetic diversity from the very beginning.Fossils from Sima de los Huesos, Spain (430,000 years old)—representing their pre-Neanderthal ancestors—displayed just as much diversity as early Neanderthals. This suggests that Neanderthals began as a genetically diverse species, only to lose much of that variation later.The causes of this genetic bottleneck remain uncertain, but several theories have emerged. One possible explanation is climate change, as extreme cold periods may have drastically reduced food sources, forcing Neanderthal populations into decline. Another hypothesis considers the role of competition with other hominins, particularly Denisovans, who occupied overlapping territories. While Homo sapiens were not yet widespread in Eurasia at this time, interactions with other hominin groups may have contributed to resource pressures. Some researchers suggest that disease outbreaks could have played a major role, with a sudden epidemic devastating isolated Neanderthal groups, leaving only a small surviving population. Finally, the study also challenges previous assumptions that Neanderthals had undergone an earlier genetic bottleneck at the origin of their lineage. Fossil morphology contradicts this idea, as early Neanderthals displayed as much diversity as their pre-Neanderthal ancestors, indicating that the species originally possessed a higher degree of variation than previously thought.Comment Save my name, email, and website in this browser for the next time I comment.

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