In the earliest stages of development of a human embryo, it has a little tail. This tail measures about 1/6th the size of the entire length of the embryo (the equivalent of a 12-inch tail on a 6-foot man). But as the fetus develops, the tail is absorbed. Enzymes dissolve the bones, and the entire structure retracts into the fetus's body.
Sometimes, for a variety of reasons, a baby is born with its vestigial tail still attached. According to the National Institute of Health, "There have been 23 vestigial tails reported in the literature since 1884," or approximately one baby born with a tail every 5 ½ years.
In most cases, the tail is just a small little tag sticking out from the base of the spine. But in some remarkable cases, the tail can be unusually long, or the owner may have motor control over it. One of the most surprising cases of a human vestigial tail belongs to a tea plantation worker in West Bengal, India named Chandre Oram, who has a tail that is 13 inches long and covered with dense hair.
He is regarded locally as an incarnation of Hanuman, the monkey god. Locals report that their ailments have been miraculously healed after they touched his tail. Unfortunately, Oram remains single, despite his search for a wife. Approximately twenty women have so far rejected his marriage proposals, because they refuse to accept his tail.
Many medical professionals regard Chandre Oram's tail as not being a true tail, but instead being an extremely rare form of spina bifida. Spina bifida is a birth defect (often caused by a lack of folic acid during conception and the early stages of pregnancy) where the spinal tube does not close properly. This causes spinal fluid to bulge out, and a small fleshy pouch sometimes forms.
This second kind of tail (caused by spina bifida, and not by a genetic abnormality which keeps the fetal tail from being reabsorbed) is considered more common. One tip-off that a human tail has been caused by spina bifida is the tail's location.
A true tail will project out from the very bottom of the spinal column, being an extension of the coccyx or tailbone. A tail caused by spina bifida will be attached somewhere higher on the back. In the case of Chandre Oram, the tail appears to be attached in his lumbar region, well above his coccyx. Other tails caused by spina bifida can happen even higher, all the way up to the base of the neck.