PBS Eons writes “We’re the only primate without a coat of thick fur. It turns out that this small change in our appearance has had huge consequences for our ability to regulate our body temperature, and ultimately, it helped shape the evolution of our entire lineage.”
Steven B
Easy answer: When humans learned to make fire they also learned what burning fur/hair smells like…primitive conclusions:
Oont: “Fire bad…”
Groont: “No…fire good…fur bad”
And, well, after some years of experimentation, they found that a certain poultice smeared over the body, while draped in animal skins, would remove hair and leave the skin silky soft. After generations of doing this, their bodies gave up producing hair and fire definitetly became VERY good indeed…