Human embryos have tails.
Possible Answers- True or false
Correct answer- True
A delicious (although not entirely accurate) witticism on this situation is that 'Ontogeny recapitulates phylogeny,' or embryonic development mirrors the evolutionary process. Although the human embryo doesn't entirely follow the evolutionary path, it does in some respects. If we never had creatures in our background with tails, why would our embryos ever have them?
7. Embryos don't have tails. You may want to do a bit more research and see how the whole of idea of vestigial organs is debunked.
There is absolutely no question that tails in humans do exist- both in all embryos and occasionally as vestigial tails in babies. Here are some links and information from scientific sources:
Fetal development: What happens during the first trimester?
“[At 9 weeks post-gestation] the embryonic tail at the bottom of your baby's spinal cord is shrinking, helping him or her look less like a tadpole and more like a developing person.”
The Fetus- Tail
“True vestigial tails… contain normal skin, connective tissue, muscle, vessels and nerves.”
“Fetal tail is a normal feature during embryonic development that should regress by the 8th week. Its persistence has been described beyond the 8th week… During the 5th-6th week, the human embryo has a tail with 10 to 12 vertebrae. Then, it starts to regress, reducing the number of vertebrae by fusion, leaving the vestigial coccyx. By this process, at 8 weeks, it disappears, although the exact moment varies. The persistent tail probably arises from the most distal non-vertebrate remnant of the embryonic tail.”
“Bartels …described five types of rudimentary
caudal appendages in man: three of these are variations
of a “soft” tail presumably arising from the embryonic
tail, the fourth is a bony tail caused by hypertrophy of the
sacrococcygeal vertebrae and the fifth is a true animal
tail containing additional vertebrae. “
Human tails and pseudotails.
“The true, or persistent, vestigial tail of humans arises from the most distal remnant of the embryonic tail. It contains adipose and connective tissue, central bundles of striated muscle, blood vessels, and nerves and is covered by skin. Bone, cartilage, notochord, and spinal cord are lacking. The true tail arises by retention of structures found normally in fetal development.”
I should mention here an argument found on many anti-evolution and anti-abortion websites- claims such as “the end of the spine sticks out noticeably in a one-month embryo, but that's because muscles and limbs don't develop until stimulated by the spine . As the legs develop, they surround and envelop the coccyx, and it winds up inside the body”
This is a misstatement. See the source “The Fetus-Tail” above for an explanation of what really occurs- dynamic change in the structure that becomes the coccyx. The same source goes on to state that humans never have true tails- “It doesn't have any bones in it; it doesn't have any nerve cord either.” which is also proven false above.
Modern-day scientists do not claim that the coccyx is vestigial, in the sense of “now useless.” The point is, the coccyx evolved from vertebrae that were once part of a tail, now fused together into something that is called “a tailbone” for a reason.