A recent analysis has uncovered a genetic link between Denisovans, an extinct species of humans, and modern-day Indigenous American populations. The study, conducted by evolutionary biologist Emilia Huerta-Sánchez and colleagues, reveals that a specific genetic variant inherited from Denisovans may have provided a survival advantage in the Americas.
The MUC19 region of the human genome codes for a mucin protein involved in forming mucus. Research found that Indigenous Americans are more likely to carry a particular variant of this gene, which can be traced back to Denisovans. This variant did not appear directly in modern humans’ DNA but was introduced through multiple introgression events involving Neanderthals and other human species.
The study discovered that the Denisovan chunk of DNA is present at high frequencies within ancient Indigenous American genomes found in Alaska, California, and Mexico. Contemporary Latino Indigenous Americans also exhibit this signature Denisovan gene. Researchers believe that the expansion of repeated sequences in the MUC19 region may have provided an adaptive role, allowing modern humans to cooperate with beneficial microorganisms or reject harmful ones.
The discovery sheds new light on human evolutionary history and highlights the importance of studying genetic variation. It is suggested that the Denisovan-like genes may still hold a functional role for Indigenous American populations in the future.
Source: https://www.sciencealert.com/denisovan-mucus-gene-may-have-helped-humans-survive-in-the-americas