Scientists from New York University Langone Health have made a groundbreaking discovery regarding the loss of tails in humans. Through their research, they have identified the genetic mutation responsible for this evolutionary change that occurred approximately 25 million years ago. The findings, published in the prestigious journal Nature, shed light on a question that has intrigued scientists for years.
Lead study author Bo Xia expressed his fascination with the topic, stating, “Our study begins to explain how evolution removed our tails, a question that has intrigued me since I was young.” The researchers focused on a specific segment of DNA that is shared by apes and humans but absent in monkeys. This segment, known as AluY, was randomly inserted into early humans and non-tailed apes during prehistoric times, leading to the loss of the tail gene TBXT.
The study revealed that the AluY snippet interacts with TBXT to produce two types of ribonucleic acid (RNA), which are crucial for cellular structure. These RNA variations ultimately resulted in the loss of tails in both humans and apes. Dr. Jef Boeke, the Sol and Judith Bergstein Director of the Institute for Systems Genetics, emphasized the significance of this finding, stating, “This finding is remarkable because most human introns carry copies of repetitive, jumping DNAs without any effect on gene expression, but this particular AluY insertion did something as obvious as determine tail length.”
To further validate their hypothesis, the scientists conducted experiments using mice. They inserted AluY into 63 mice and observed that the offspring either had shorter tails or were completely tailless. These results provided additional evidence supporting their theory.
Interestingly, the study also suggested a potential link between tail loss and an increase in neural tube defects. Neural tube defects can lead to conditions such as spina bifida, where the spine does not align properly with the spinal cord. Dr. Itai Yanai, one of the study authors, stated, “Future experiments will test the theory that in an ancient evolutionary trade-off, the loss of a tail in humans contributed to the neural tube birth defects.”
The discovery of the genetic mutation responsible for tail loss in humans opens up new avenues for research into the evolutionary history of our species. By understanding the mechanisms behind such significant changes, scientists can gain insights into the development of various traits and characteristics.
This study highlights the power of genetic research and its ability to unravel mysteries that have puzzled scientists for centuries. The team at New York University Langone Health has taken a significant step forward in our understanding of human evolution and the factors that have shaped our species over millions of years. As further experiments are conducted, we can expect even more fascinating discoveries that shed light on our complex genetic makeup.
