I was reading up on 29 Evidences for Macro-evolution as suggested by @Christy and came across the “Anatomical Vestiges” portion of the article.
“Yet another human vestigial structure is the coccyx, the four fused caudal vertebrae found at the base of the spine, exactly where most mammals and many other primates have external tails protruding from the back. Humans and other apes are some of the only vertebrates that lack an external tail as an adult. The coccyx is a developmental remnant of the embryonic tail that forms in humans and then is degraded and eaten by our immune system (for more detail see the sections on the embryonic human tail and the atavistic human tail). Our internal tail is unnecessary for sitting, walking, and elimination (all of which are functions attributed to the coccyx by many anti-evolutionists). The caudal vertebrae of the coccyx can cause extreme and unnecessary chronic pain in some unfortunate people, a condition called coccydynia. The entire coccyx can be surgically removed without any ill effects (besides surgical complications), with the only complaint, in a small fraction of patients, being that the removal of the coccyx sadly did not remove their pain (Grossovan and Dam 1995; Perkins et al. 2003; Postacchini Massobrio 1983; Ramsey et al. 2003; Shaposhnikov 1997; Wray 1991). Our small, rudimentary, fused caudal vertebrae might have some minor and inessential functions, but these vertebrae are useless for balance and grasping, their usual functions in other mammals.” (Emphasis Mine)
Digging further I clicked on the “embryonic human tail” link which took me to this…
“Humans are classified by taxonomists as apes; one of the defining derived characters of apes is the lack of an external tail. However, human embryos initially develop tails in development. At between four and five weeks of age, the normal human embryo has 10-12 developing tail vertebrae which extend beyond the anus and legs, accounting for more than 10% of the length of the embryo (Fallon and Simandl 1978; Moore and Persaud 1998, pp. 91-100; Nievelstein et al. 1993). The embryonic tail is composed of several complex tissues besides the developing vertebrae, including a secondary neural tube (spinal cord), a notochord, mesenchyme, and tail gut. By the eighth week of gestation, the sixth to twelfth vertebrae have disappeared via cell death, and the fifth and fourth tail vertebrae are still being reduced. Likewise, the associated tail tissues also undergo cell death and regress.” (Emphasis Mine)
This is something I never heard of before… so I clicked on the images for more details on the Embryology.
http://embryo.soad.umich.edu/index.html <<< this is the link to Embryonic photos of a developing baby.
The author states that the remnants of the tail are most visible in pictures 14, 15, and 16, — it’s called the Neural Tube. And, according to the author, this tail gets digested due to cell division, preventing an actual tail from occurring. In stage 23 you can see the extreme differences in the Neural Tube.
I further investigated and clicked on the “Avatistic Tail” link to show human babies actually born with tails (very rare however). The site provided links —
So I’ve seen both the Embryonic tail and the “post-Embryonic tail” and it seems convincing to me. I’m not sure how to explain the existence of such of an expenditure without resorting to Common Descent explanations.
What do you guys think?