Virtual Reconstruction Of A Neanderthal Woman’s Birth Canal Reveals Insights Into Evolution Of Human Child Birth

[Nikos]

http://www.sciencedaily.com/releases...0528133423.htm

Although the size of Tabun’s reconstructed birth canal shows that Neanderthal childbirth was about as difficult as in present-day humans, the shape indicates that Neanderthals retained a more primitive birth mechanism than modern humans. The virtual reconstruction of the pelvis from Tabun is going to be the first of its kind to be available for download on the internet for everyone interested in the evolution of humankind (PNAS, April 20th, 2009).
Childbirth in humans is more complicated than in other primates. Unlike the situation in great apes, human babies are about the same size as the birth canal, making passage difficult. The birth mechanism, a series of rotations the baby must undergo to successfully navigate its mother’s birth canal, distinguishes humans not only from great apes but also from lesser apes and monkeys.
It has been difficult to trace the evolution of human childbirth because the pelvic skeleton, which forms the margins of the birth canal, tends to survive poorly in the fossil record. Only three fossil female individuals preserve fairly complete birth canals, and they all date to earlier phases of human evolution.
Tim Weaver of the University of California (Davis, USA) and Jean-Jacques Hublin, director at the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) now present a virtual reconstruction of a female Neanderthal pelvis from Tabun (Israel). The size of Tabun’s reconstructed birth canal shows that Neanderthal childbirth was about as difficult as in present-day humans. However, its shape indicates that Neanderthals retained a more primitive birth mechanism than modern humans, without rotation of the baby’s body.
A significant shift in childbirth apparently happened quite late in human evolution, during the last 400,000 - 300,000 years. Such a late shift underscores the uniqueness of human childbirth and the divergent evolutionary trajectories of Neanderthals and the lineage leading to present-day humans.
The virtual reconstruction of the pelvis from Tabun is going to be the first of its kind to be available for download on the internet for everyone interested in human evolution. The computer files will be available from the websites of University of California at Davis and the Max Planck Institute for Evolutionary Anthropology.

Awesome! It seems that the human method of child birth only evolved within the last 400,000-300,000 years! That is very late, I'm very surprised. This also shows how unique our method of birth is with all the rotations and such. We truly are unique!

[Viking Prince]

Do you know of any evolutionary advantages to the more difficult process? I would think there must be or why the evolved change.

[Nikos]

Do you know of any evolutionary advantages to the more difficult process? I would think there must be or why the evolved change.

In humans and Neanderthals, the size of the fetus is abot the same as the birth canal. Neanderthals were more robustly built then humans are and probably did not need the rotations, In human beings, the rotations are necessary because of the size of the head. Human babies have large heads!

[FaneFlugt.DK]

From the look of it they are missing the sacrum, you would need that to make any final assumptions. Further one example of an Neanderthaler pelvis is to little to base a theory on, in my opinion. The text mentions three pelvis, but they arent included in the test, they should be.

[Nikos]

From the look of it they are missing the sacrum, you would need that to make any final assumptions. Further one example of an Neanderthaler pelvis is to little to base a theory on, in my opinion. The text mentions three pelvis, but they arent included in the test, they should be.

From the evidence we have however, it is a pretty good theory IMHO.

[IndianPrince]

Whats the reason to the pelvic fossilization being so rare or being hard to form/find ?

Prince

[chamaeleo]

Whats the reason to the pelvic fossilization being so rare or being hard to form/find ?

Prince

They's considerably more fragile than most bones, thus the prevalence of femurs in the fossil record.

Great find, Nikos! Somewhat relevant annecdote: my boss's pregnancy was complicated by the fact that her kid's head constricted her bladder, and she didn't pee for over 30 hours. I cannot imagine the pressures of carrying a overly large kid in the wrong orientation, there's only so much space for the rest of your organs to squish around for accomodation. So glad I have a penis.

[Nikos]

I cannot imagine the pressures of carrying a overly large kid in the wrong orientation, there's only so much space for the rest of your organs to squish around for accomodation. So glad I have a penis.

QFT

Whats the reason to the pelvic fossilization being so rare or being hard to form/find ?

Prince

What chamaeleo said, the bones of the pelvis are considerably more fragile then other bones that do survive.

[FaneFlugt.DK]

So glad I have a penis.