Primate evolution: old fossil, old news?

July 15, 2010 • 4:44 am

by Matthew Cobb

The question of why some research articles get published in high-profile scientific journals is one that perpetually preoccupies scientists (or at least, those of us who don’t habitually publish in such journals), and has been discussed here a number of times. The latest issue of Nature raises this question again.

Nature – a commercial publication – is one of two weekly science journals that has a high public and academic profile, and which publishes material covering the whole range of scientific endeavour. (the other is Science). To keep up its profile – and thereby its profits – Nature has to have a keen eye for research that is sexy and exciting. One person’s sexy is another’s dull, of course, and sometimes it’s hard to see what made the editor’s eye gleam – I’m happy to admit that I don’t understand the titles of many of the articles in Nature (“Intra-unit-cell electronic nematicity of the high-Tc copper-oxide pseudogap states” for example, which I’m sure is really fantastic, but I don’t get it…).

This week’s Nature has a dramatic cover of a frontal view of a battered fossil primate skull, with the headline “The parting of the ways”. Sure looks sexy:

The associated article, by Zalmut et al, is entitled “New Oligocene primate from Saudi Arabia and the divergence of apes and Old World monkeys“. It describes the skull of a new species, Saadanius hijazensis, which was found in Saudi Arabia and is an early (“stem”) catarrhine. “Catarrhine” is the term that describes old world monkeys and the apes (including us), which split away from the New World Monkeys (platyrrhines) around 40 MY ago. Exactly when the apes split from the old world monkeys has been a matter of some discussion, and this fossil, which has few catarrhine specialisations, dates to 28-29MY ago, suggesting the split took place after this date.

Here are the details of the fossil:

Original caption: a, Cranium in anterior view. b, Cranium in lateral view, anterior to the left. c, Ventral view of cranium, anterior to the left. d, Anterior view of right temporal bone, ventral at top, lateral to the right. e, Ventral view of right temporal bone, anterior at top, lateral to the left. f, Medial view of right occipital condyle, anterior to the left. g, Ventral view of right occipital condyle, anterior to the left. cf, carotid foramen; egp, entoglenoid process; gf, glenoid fossa; pgp, postglenoid process; smf, stylomastoid foramen; te, tubular ectotympanic.

The authors also include this useful diagram of primate evolution and the place of Saadanius within it. This will no doubt feature in many future lectures on primate evolution:

Is this Big News? Well probably not. When I suggested to Jerry he might blog on this, he mailed back “so what?” (He didn’t use those exact terms, but something more robust…). As he pointed out – “If it was a fly ancestor it would go to Drosophila Information Service…” (DIS – a highly valued publication – is pretty much what it says, and not exactly Nature.)

Basically, the fossil provides physical evidence that the split took place <28 MY ago (the previous youngest stem catarrhine fossil was from around 30 MY), which fits in which the molecular data, suggesting there may have been an early-Oligocene split (i.e. 23 MY at the earliest). Is that something that’s really amazing? I’m not sure. But the Nature editors obviously thought so.

Interestingly, the part of the story I found the most fascinating appeared in today’s Guardian, in an article by Ian Sample, which in its earlier editions appeared with a dramatic picture showing the skull in situ and goes on to describe how the poor animal met its end:

Iyad Zalmout, lead author of the study, spotted the damaged skull of Saadanius lying upside down in the sediment with its teeth glinting in the sun. Serious wounds on the front of the skull suggest the creature met a violent end. “He got in the way of a big carnivore and died in a horrible way,” Zalmout said. “The puncture marks in the skull suggest he was seized by the head, got chewed around a bit, and was then thrown away.”

Brenda Benefit, professor of biological anthropology at New Mexico State University, said: “For me this discovery is one of the most significant in my lifetime. Until now we have not had a very perfect fossil ancestor for the Old World monkeys and apes.”

“Some palaeontologists, inlcuding myself, thought that this is exactly what the common ancestor to Old World monkeys and apes would look like, based on resemblances between Miocene fossil Old World monkeys and apes, whereas others thought they would be shorter snouted and more round-headed like modern gibbons.

Saadanius resolves this debate and demonstrates the importance of the fossil record for knowing what our ancestors looked like.”

Now that’s a lot more convincing. Maybe for once the science journalist got it right, while the scientists and the journal editors didn’t.

Note to creationists: this post is not about the validity of the discovery, it’s more a reflection on our views about what is and is not noteworthy in science.

UPDATE: The BBC website also reports this and concludes with this underwhelming phrase: “The new date, of 29 million years ago, fits more closely with what the researchers would have expected and is not surprising from a palaeontological point of view.” So Nature is putting “not surprising” results on its front cover…

Reference: Iyad S. Zalmout, William J. Sanders, Laura M. MacLatchy, Gregg F. Gunnell, Yahya A. Al-Mufarreh, Mohammad A. Ali, Abdul-Azziz H. Nasser, Abdu M. Al-Masari, Salih A. Al-Sobhi, Ayman O. Nadhra, Adel H. Matari, Jeffrey A. Wilson & Philip D. Gingerich (2010). New Oligocene primate from Saudi Arabia and the divergence of apes and Old World monkeys. Nature 466:360-364. [Subscription needed to see beyond abstract.]

18 thoughts on “Primate evolution: old fossil, old news?

  1. Meh, we all know why it’s “sexy”: “ZOMG a Missing Link!!1!1!11!!!!” For those laypeople who mistakenly think there is an evolution controversy but are prone to be sympathetic to the science-side of things, this makes them excited. For Creationists, it makes them enraged. Both get media attention.

  2. That was worth chewing on for a while.

    (But with a prototypical baboon snout it will be so much easier.)

    “Intra-unit-cell electronic nematicity of the high-Tc copper-oxide pseudogap states” for example, which I’m sure is really fantastic, but I don’t get it…

    Let me see if I can parse that for you; it’s an interesting mirror to your topic. [Disclaimer: I should have been, but it was a while since my solid state days and I haven’t kept up…]

    “the high-Tc copper-oxide”

    This mean it is a high temperature superconductor of the ubiquitous copper-oxide kind. (Tc is the superconductor critical temperature below which it conducts in the superconductor state.)

    Elucidating the mechanism of high temperature superconductors is one of the key areas in solid state physics, because it is: economically and socially interesting (low loss/high efficiency power technology), it is a now 20 year old mystery, and it was an unexpected phenomena.

    “pseudogap states”

    One of the hall marks for the superconducting state, as for many other electronic states, is a bandgap. Depending on the crystal topology, available quantum interactions, et cetera, it may however not be a true bandgap in all circumstances for the energy levels concerned. Hence “pseudogap”.


    Electron states may be more (localized electrons) or less localized (conduction electrons) in a conductor. These states are localized.

    “electronic nematicity”

    Huh! Now I would need the paper. This must be a loan from liquid crystal phases, where a nematic phase has the “standing lenses topology”. Apparently these localized electron states looks a lot like them when in their “intra-unit-cell” positions; enough to warrant a measure of their own. They would also have the same topological defects, which would be interesting with respect to the superconducting mechanism.

    In sum, probably a technical achievement (or not!) that shows some new physics to digest on an old and thoroughly scrutinized topic. In your words: “Is that something that’s really amazing? I’m not sure. But the Nature editors obviously thought so.”

    OTOH I’ll bet they would be sorry if the new information would unlock the area and lead to new Noble prizes, and someone else was publishing it. Their thinking may go “better safe than sorry; we can afford it”.

    1. Thanks for clearing that up. I figured it was something to do with superconductors but I wasn’t sure what.

  3. How do we encourage good science writing?

    I would suggest that it is not encouraged by phrases such as “Maybe for once the science journalist got it right…”

    I read a lot of science journalism, and used to nibble around the edges of it myself before moving on to other things (what I do now pays WAY better).

    I would suggest if you want to know what it’s like to be a science journalist that you summarize the Nature report on “Intra-unit-cell electronic nematicity of the high-Tc copper-oxide pseudogap states” in 750 words, using language that an 8th grader could understand. Do this in about two hours from the time you start until the time you stop, including time on the phone spent trying to contact both the author of the paper and a noted expert in that field who is not associated with the research.

    Do something similar twice a day, 5 days a week (when I was in journalism, my output was that PLUS a Sunday piece, PLUS work on an investigative story, so you’re getting off lightly).

    Is there a bell-shaped curve of competency in science journalism? You bet. Just like there’s a bell-shaped curve of competency in science, in science blogging, and in deep-water oil well drilling. But one does not improve the profession by only sniping or damning with faint praise.

    /End of rant.

    1. If it is that time limited a profession, I believe my “safe” option is the more relevant one.

      But I am, and maybe you too, then cutting the editors out of the loop, something that Cobb didn’t.

      As for the rest: yes!

      Until that last sentence on criticism. I think any criticism is of value. However, your point that there ought to be more diversity of it is well taken. That in turn would depend on getting more information on the profession, along the lines that you just made.

    2. “for once” was ill-judged. I was trying to contrast this particular piece by Ian Sample with the nonsense about chickens and eggs in the Daily Mail that Jerry was complaining about in the previous post (and which was no doubt at least partly the responsibility of the scientists/university media officers).

      1. Thanks for the clarification and the mea culpa.

        Perhaps some way to encourage people to read excellent science journalism should be a goal of this and/or other science blogs?

        Maybe something akin to the “Eat This, Not That” series…”Read Her, Not Him”?

    3. Until I got to the following phrase, I was brashly saying to myself, “Hell yeah I could do it!”

      Do this in about two hours from the time you start until the time you stop,

      Okay, ouch. Give me five or six hours, and I’m actually pretty sure I could do a decent job of it. I have not read Torbjorn’s deconstruction of the title, so maybe I don’t know what I’d be getting myself into… but I’m not one of those people who is frightened by big words or abstract concepts, and I can usually get at least a vague notion of what’s going on with a technical subject pretty quickly.

      But two hours, to condense a paper on an unfamiliar subject AND get an interview with the author of the paper? You’re right, that’s brutal.

      1. It’s not a profession for slow typists, that’s for sure.

        My record from zero to finish for an 11-column inch story (about 1,000 words) that made the section front was 20 minutes. On deadline, with an editor screaming at me (so they could write a headline) while I was both typing my initial source’s comments AND interviewing a second source. I do not recall the subject — or if the story was really any good in the end.

  4. I’m not sure that I understand the complaint here. The Nature article emphasizes the morphology of the fossil just as much as the scientist interviewed for the popular article does. The date isn’t particularly surprising (and the article really only devotes a few lines to that, anyway), but the morphology is great for those of us in the field to look at. I get that you don’t deem the little guy Nature-worthy, but what did the popular article get right that the scientists missed?

    1. I agree with this comment. It seems that Matthew Cobb, who has no expertise in paleoanthropology, thinks Saadanius isn’t significant, while Nature and those with actual knowledge of the issues at stake do think it’s significant. I’ll go ahead and trust the latter and lower my opinion of the former.

  5. If you will bear with me, a bit of reflection on the words “catarrhine” and “platyrrhine”:

    I doubt that there are precious few among science majors who, when first confronted with such exotic terms in high school and later in college, did not have to make do with brute-force memorization in order to remember their meanings. For the most part my teachers spouted words to be memorized. (E.g., in high school Latin, the “genitive” case would have made some sense had the word been compared to genesis, generation, gender, genial. Same with the “ablative” case re: “ablation” of the many layers of the heat shield of a space capsule.)

    Anyway, one day in my older post-college age it occurred to me to start considering a GOOD dictionary (showing the etymological history, generally Greek and Latin) my good friend to help find etymological clues to make it much easier to remember the meanings of such words.

    Hence, “Catarrh” – “down” + “run.” I.e., mucus running down the throat due to mucous membrane inflammation, perhaps more likely to happen the more “catarrhine” – narrow – ones nasal passages, as with the New World monkeys, as contrasted with the “platyrrhine” (re: plate, platter, plateau), the flatter, broader, wider nose, nasal passages of the Old World monkeys, apes, humans.

    (Re: “rhino,” “rhinoceros,” “nose” + “horn” —>”ceros” [re: “triceratops – “three” + “horns”] –> Gk. “keras,” hence “keratin,” substance making up making up horns, claws and nails.

    Said in the spirit of finding ways to make science (and math) more engaging and interesting to the easily-bored, entitled, spoiled “Entertain Me” generation.

    1. Good idea!

      Caveat: “from New Latin Catarrhina (for sense 1), all ultimately from Greek katarrhin having a hooked nose, from kata- down + rhis nose” [TheFreeDictionary. This makes more sense to me, having the nose physiology as term originator/comparator.

  6. In second para., first sentence of my previous post, amend “I doubt” to “I do NOT doubt.” Apologies for the brain cramp.

  7. I find it interesting how our own evolution gets oodles of screen-time (or page-space, whichever) when the evolution of less prominent but much more interesting creatures (e.g. millipedes, liverworts, slime molds) are lucky if they get a short mention in an unrelated article.

  8. Flies are very cool to be sure, but this fossil anthropoid helps to resolve an interesting debate in primate evolution — and it’s one well articulated by the authors and by Benefit (per zinjanthropus’ comment and query). Virtual ancestors conjured up by algorithms based on character states in living species often need a reality check — AKA the fossil record. Long live paleontology!

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