This is a bit of a trick question, as technically all primates, including great apes, have hair, not fur. The distinction lies in density and texture. “Fur” is typically denser and softer. Over the last 40 million years, primates have experienced a gradual reduction in hair density, resembling a process of “going bald.” For instance, the hair on a chimpanzee is much sparser than the fur on a ring-tailed lemur.
The common ancestor of humans and chimpanzees, which split about 7.5 million years ago, almost certainly had a dense, ape-like coat, but with a body-wide follicle pattern already similar to modern apes and humans. After this split, hominins did not so much lose hair as progressively miniaturize it, producing finer, shorter strands across most of the body. The sparse, human-like appearance we recognize today likely finalized within the last few hundred thousand years. However, evidence suggests that Homo erectus, around 1.5 million years ago, may have already exhibited substantially reduced body hair—especially in thickness and length—likely tied to endurance walking, running, and heat regulation, though research on this remains ongoing.
Importantly, this means the basic map of human hair follicles is ancient, likely predating the human–chimp split itself — a pattern in primates that likely goes back over 50 million years. Modern humans and chimpanzees have roughly the same number of hair follicles, arranged in nearly identical patterns. What changed over time was not where hair grows, but how each follicle behaves—a shift from thick, insulating fur to fine, heat-dissipating hair.
Even today, humans display a wide range of hairiness, reflecting the complex evolution of our unique hair patterns. The great apes, which include orangutans, gorillas, chimpanzees, and humans, all have hair. The evolution of great ape-like hair likely occurred about 20 million years ago. Sparse human-like hair patterns began to evolve more distinctly after 3 million years ago, coinciding with significant changes in habitat and lifestyle.