What if Humans Had Kept Their Tails?

Humans once had tails—just like monkeys and most vertebrates. So why don’t we now? A new study pinpoints a tiny genetic change as the turning point in our ancestry.

🔬 **In this video, you'll learn:**

1. How our embryos briefly grow a tail during weeks 5–6, which then vanishes into the coccyx or tailbone. Rarely, it doesn’t regress—resulting in infant tail-like protrusions. (University of Melbourne, Wikipedia)

2. The big surprise: scientists discovered that jumping DNA elements—called Alu sequences—inserted into the gene TBXT triggered tail loss about 25 million years ago, coinciding with the evolution of apes. (Live Science, Science News)

3. Why it happened: Apes benefited from being tailless—tail loss may have aided upright posture and arboreal brachiation (arm swinging), making life in trees easier and walking more efficient. (University of Melbourne, Live Science)

4. Evolutionary tradeoff: mice engineered with this same mutation lost their tails but also had higher risk of spinal defects like spina bifida—suggesting a risky but beneficial evolutionary decision. (Science News, Live Science)

🚀 From embryonic trails to gene sparks, this tail-free journey shaped the primates—including us—that rule Earth today.

👍 Like, Comment: What would you do with a tail? Subscribe for more curious stories from evolutionary science!

---

🔖 Hashtags:

#Evolution #HumanAnatomy #Vestigial #TBXT #AluElements #Tailbone #GeneticMutation #LiveScience #ScienceAlert