Are we just cousins of gibbons?

We’ve all seen the depictions of the “Tree of Life” with humans at the top (older versions had some races closer to the top than others), but as leading evolutionists have pointed out, that’s a misleading view of evolution. Indeed, it was held by a number of leading evolutionists in the past, who saw evolution as just such a progression of increasingly superior or “fitter” organisms leading up to us (and someday to descendants of ours so advanced we would look little different from chimps in comparison).

The more popular view these days is to emphasize that humans are nothing special in evolutionary terms. After all, look at the microbes that today leave traces (stromatolites) that appear identical to fossils dated billions of years old. How’s that for surviving? Humans are just the latest fad in this view, our tiny twig on the tree of life not being any more special or favored than any of the others. The perch we may eat for supper is seen as just as evolved in its own way as we are, and from the same fishy ancestor. For that matter, I might just as easily have titled this post, “Are we just colonies of specialized microbes?” However, it was inspired by a recent report a lot closer to home in evolutionary terms.

The story goes that around 6 million years or so ago, there lived a population of creatures most of us would call apes, from which gradually evolved the modern apes and, right alongside them, the ape-like creatures which over generations became more like us until … uh, they were us. That is, at some point (perhaps the recently discovered H. naledi, an evolutionist might say) they were more like us than like the ancestors we share with “other” apes.

Likewise, that common ancestor evolved from an ancestral population that was more like monkeys, which also evolved into gibbons and siamangs, our smaller, slimmer cousins. Perhaps it was something that went along with the old view of progressive evolution, or maybe just that there are more branches on our side of the split, but evolutionists had expected that this common ancestor of all apes would tend to look more like a hominoid ape (us, and our “close cousins” such as the chimps and gorillas), than the gibbons (and siamangs).

So, they were a bit surprised when an ape fossil they dated to more than 11 and a half million years ago turned out to look a lot like a gibbon as well as having some hominoid features.  The original research report in Science notes that trying to figure out what the common ancestor at this point would have looked like “is complicated by the mosaic nature of ape evolution, the confounding effects of independently evolved features (homoplasy), and the virtual lack of hylobatids (gibbons and siamangs) in the Miocene fossil record. ” Ah… complicated, indeed. Well, now this new fossil ape, Pliobates cataloniae, may be complicating things a bit more, if anything. Its “mosaic” of features is pretty much all over the map, with “primitive” monkey-like aspects, the surprising number and degree of gibbon-like traits, and enough hominoid-like traits to put it just this side of the split between gibbons and hominoids.

Ah well, perhaps someday it will occur to these researchers that they’ve just found one more extinct variety of ape. At least in this case they recognize it might not represent the ancestors of hominoids (according to the UPI report).

But as with most studies of this nature, the findings aren’t entirely clear. The new species could also be a close relative of ancient gibbons, its great ape features simply a coincidence of evolution.

“Pliobates might be the sister group of extant gibbons only,” admitted study co-author Salvador Moya-Sola, director of the ICP. “We hope that future discoveries in the landfill of Can Mata will help us to clarify the role played by small-bodied catarrhines in hominoid evolution and, finally, to solve the enigma of extant gibbons’ origins.”

Hang in there, guys, you’ve only been trying to figure out evolution for a 150 years or so. Look how little progress has been made in that time in electroni… uh, chemis…. phys…  Hmm, you guys have a lot of catching up to do!


Science 30 October 2015:  Vol. 350 no. 6260
DOI: 10.1126/science.aab2625
Miocene small-bodied ape from Eurasia sheds light on hominoid evolution
David M. Alba, et al. 


Newly discovered fossil could be apes’ common ancestor
Scientists expected apes’ common ancestor to have mostly great-ape features, but that appears not to be the case.
By Brooks Hays | Oct. 29, 2015 at 6:08 PM

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