A genetic change in our ancient ancestors may partly explain the absence of tails in humans compared to monkeys, according to a recent study led by researchers at NYU Grossman School of Medicine.
Researchers at NYU Grossman School of Medicine compared the DNA of tailless apes and humans with that of tailed monkeys, revealing an insertion of DNA, AluY, shared by apes and humans but missing in monkeys. By engineering mice to examine the effects of this AluY insertion in the TBXT gene related to tail development, the study found various tail effects, including some mice born without tails. The research addresses the genetic basis of tail loss in human evolution, highlighting the insertion’s influence on alternative splicing and resulting in diverse tail lengths. The study emphasizes the intricate nature of genetic regulation and its role in species evolution. The research suggests that tail loss in primates, including humans, occurred around 25 million years ago, potentially adapting to ground life. Future experiments will explore potential trade-offs and the impact of tail loss on neural tube birth defects.