An elongated tailbone occurs rarely in some newborn children, what does the presence of a tailbone indicate? . a)that the tail will grow in length as the child grows. b)that our early ancestors were tailed primates. c)that the child's genome must have undergone mutation.
The correct answer is option b) "That our early ancestors were tailed primates".
Rarely, some newborn children developed an elongated coccyx, known as an elongated tailbone or a pseudotail. This is an example of vestigiality, which is the presence of ancient body structures that do not longer serve a purpose. In this case, vestigial tails indicate that our early ancestors were tailed primates. Other examples of human vestigiality include wisdom teeth, appendix, and body hair.