Thursday, 10 August 2017

Just Another of Those Mythical 'Missing Links'

Alesi, the skull of the new extinct ape species Nyanzapithecus alesi (KNM-NP 59050).

Photo © Fred Spoor
The Leakey Foundation | New 13 million-year-old infant skull sheds light on ape ancestry

It's another bad week for creationism. Is there ever a good week?

Close on the report of the earliest known primate fossil we now have the remarkably complete skull of an infant who lived 13 million years ago in what is now Kenya, and which is close to the common ancestor of the hominids and the other African apes. It gives us a fairly good idea of what the last common ancestor would have looked like.

The skull was found by fossil hunter John Ekusi in 13 million year-old rock layers in the Napudet area, west of Lake Turkana in northern Kenya; a formation that is easy to date reliably because of the activity of a nearby volcano. The skull, along with forest trees, was buried by volcanic ash, showing that they were buried during the same catastrophic event.

The Napudet locality offers us a rare glimpse of an African landscape 13 million years ago. A nearby volcano buried the forest where the baby ape lived, preserving the fossil and countless trees. It also provided us with the critical volcanic minerals by which we were able to date the fossil.

Craig S. Feibel
Rutgers University-New Brunswick.
The research was conducted by an international team led by Isaiah Nengo of Stony Brook University-affiliated Turkana Basin Institute and De Anza College, U.S.A., funded by a grant from Leakey Foundation.

Like the early primate fossil I wrote about yesterday, the team used the same high-definition X-ray tomography facility at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France to construct a 3-D image of the skull.

3D animation of the Alesi skull computed from the ESRF microtomographic data. It shows first the skull in solid 3D rendering, then transparent surface rendering is used to show the endocast shape (light blue), the internal ears (green) and the permanent teeth germs (grey and brown).

© Paul Tafforeau / ESRF
Abstract
The evolutionary history of extant hominoids (humans and apes) remains poorly understood. The African fossil record during the crucial time period, the Miocene epoch, largely comprises isolated jaws and teeth, and little is known about ape cranial evolution. Here we report on the, to our knowledge, most complete fossil ape cranium yet described, recovered from the 13 million-year-old Middle Miocene site of Napudet, Kenya. The infant specimen, KNM-NP 59050, is assigned to a new species of Nyanzapithecus on the basis of its unerupted permanent teeth, visualized by synchrotron imaging. Its ear canal has a fully ossified tubular ectotympanic, a derived feature linking the species with crown catarrhines. Although it resembles some hylobatids in aspects of its morphology and dental development, it possesses no definitive hylobatid synapomorphies. The combined evidence suggests that nyanzapithecines were stem hominoids close to the origin of extant apes, and that hylobatid-like facial features evolved multiple times during catarrhine evolution.

Isaiah Nengo, Paul Tafforeau, Christopher C. Gilbert, John G. Fleagle, Ellen R. Miller, Craig Feibel, David L. Fox, Josh Feinberg, Kelsey D. Pugh, Camille Berruyer, Sara Mana, Zachary Engle, Fred Spoor.
New infant cranium from the African Miocene sheds light on ape evolution.
Nature,
2017; 548 (7666): 169 DOI: 10.1038/nature23456

Copyright © 2017, Rights Managed by Nature Publishing Group
Reprinted with kind permission under licence #4165400757337

Nyanzapithecus alesi was part of a group of primates that existed in Africa for over 10 million years. What the discovery of Alesi shows is that this group was close to the origin of living apes and humans and that this origin was African.

Isaiah Nengo.
Lead author
The unerupted adult teeth inside the skull show that this is a new species, named Nyanzapithecus alesi; ales being the local Turkana word for ancestor. This is the first Nyanzapithecus species known from more than just teeth so it was not even certain that they were even apes, however, the fully-developed ear tubes inside the cranium of N. alesi places this firmly in the ape group.

Although superficially resembling a baby gibbon, the balance organ in the ear shows that this species was far less at ease swinging through the branches than the acrobatic gibbons are. It would have been much slower and more cautious.

So, that's another gap closed and the pendulum of scientific opinion swings back to Africa as the home of our's and the other African ape's last common ancestor. As is traditional in creationist circles, this will be dismissed as just another extinct ape, probably drowned a few thousand years ago in a global flood. There will be no attempt to explain why all these extinct species of archaic apes and hominids became so well sorted in the geological columns and how they just happened to be carefully arrange so it looks just as you would expect of an evolutionary change over time, or how you get buried in 13 million year-old volcanic ash during a global flood a few thousand yeas ago on a 6000 year-old earth.

Creationism isn't about fact or truth; it's about ignoring them. It doesn't need to satisfy an enquiring mind; just one eager to swallow any simple explanation that satisfies their preconceived superstition so they can tell themselves that the science they detest supports them really.

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2 comments :

  1. Another great article.
    The 3D animation was particularly fascinating to watch. Almost as good as holding the real thing in your hands and in some ways even better.

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