Science Publishes 11 Papers On Ardipithecus ramidus

October 2nd 2009 Cover of Science Magazine
October 2nd 2009 Cover of Science Magazine

There’s more than 11 citations here, but the others are associated news and media covered by Science. They’ve even dedicated a special issue to it. Very impressive thorough volume of information. Now you have a some understanding why it took so long to publish… Anyways get to reading.

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6 thoughts on “Science Publishes 11 Papers On Ardipithecus ramidus

  1. this was a very interesting read, many compliments to many aspects of the research, esp. the fieldwork and catalogisations, and the effort put in more technical analyses.

    my criticism focusses on 3 points, firstly the surroundings, i can’t help thinking ‘ardi’ got buried in a muddy place, probably a drinking place, a very lowlying and humid floodplane,(bioturbation, and the amount off slib needed to keep the particular find uncrushed, water associated animals have their teeth worn, but not animals of a dryer context, suggesting they were prey). it is only the landsnails that keep me from being convinced.

    as a result of that impression it was a drinking
    place i am also unconvinced it represents their actual habitat, but that is covered somewhat with the microfossils analyses that only poses a mosaic landscape must have been in place. an interesting aspect i find that it suggests, except crocodiles there were no predators for the ardipithecus present, indeed it looks like a somewhat clumsy and vulnerable hominid/animal.

    i am not very surprised tho, i allways thought hominids stuck to trees a long while for safety. also i think the context is suggestive of a period when it became dryer, and (i’ll reread) i didn’t find an overal climate analyses covering the awash member.

    so i think the evolutionairy value of that is that it appears to evolve to make a better use of terrestrial food sources. so moreless from a floodplains climax landscape (explaining their long term prominence) to a dryer circumstance
    wich would explain that afarensis is much more adapted to drought and plains.

    there are about two ways that ardi became distributed like she was, that is within a year, and not within a year, in both cases the actual season of dispersal is suggestively different then other years, in the first case the factors that caused the thrift (water then) must have disappeared, or be much less pronounced to remain the fossils, in the second case a flooding or some such displaced the more conserved remains, but also not to be repeated in further seasons. if we take the occurence of one example of hominid and no examples of other species as associated finds, it also strongly suggests a catastrophical (like eg flashflood) context for the find. i understand much of the displacement is interpreted as to have taken place before the weathering out.

    my next critic focusses on the derived – primitive traits theory. by no means i am convinced that evolutionairy adaption after ramidus could not produce chimpansee and human, many of the discussed traits apparently arrive in monkeys or hominids and their relatives more often, and seem to also disappear (seemingly) reverting to the primitive. so i think the time scale is much to huge to support all the new conclusions about what be derived and what primitive and in what ordre.

    also by saying the last common ancestor is even a million year older, we get the statistical problem that 1 million extra years of no chimpansee or gorilla ancestor fossil is many times more improbable.

    next in the sequence we notice a trend to much more explicit sexual dimorphism, at least in dentition, my take for now is that the pan and human lineages split after ramides,
    and probably as research some years ago suggested with kadabba or afarensis.

    for that i have one more argument, i am quite thoroughly convinced the earlier the hominid, the more (surely) subspecies existed found that in general preserved the option to interbreed over long periods.

    so i think climate change during and especially after ramidus was responsible for the split of pan and hominid lineage. perhaps because some codominant more great apelike species was ever available as a remote cousin.(wich would explain some of the clumsiness treshold of the animal).

    note that as the finds are now, this specific region appears of utmost importance to the lineage development but not much later we find afarensis almost everywhere.

    so the points are: dry.. but where did all the slib come from, and the bioturbation.

    hominid but where are the relatives, or even the animals that share the niche, and the predator,

    we dont see chimpansee only in one jungle these days, why would afarensis of chimp ancestors have a very limited geographical distribution?

    (i answer that by posing it must have known subspecies)

    and i am having difficulty with the number of traits that have now been named primitive or derived. not because i think the physical analyses moots, but because i think the new set of definitons anatomically suffers from wishfull thinking. in effect i think what now is called derived could often evolve in 100 or 200k years,
    a strange observation, chimps and gorillas really look like animal that took to (facultative)bipedality, and ‘decided’ to use their arms in locomotion.

    armlength of hominids is very slow to change, and thus the long arms that are needed to potentially develop knucklewalking would be there for some time to come after ramidus. one million years later the human foot is fully developed, never to change,
    that is another indication the foot was rapidly changing, and after ramidus, perhaps in several directions).

    to examplify that, the hands are much less human like, or great ape like, yet they easily evolve into amanensis and afarensis hands, that share the longer bones with pan and pongo. that is not meant as a quantative proof tho, just that i still feel unwieldy with the apparent certainty that several traits are newly labelled derived or primitive.(for the hands it was no problem to still change divergent or convergent, so why wud it be for eg. a pelvis.)

    very many thanks anyhow, i look forward to the discussion and developments.

  2. I’ve just realised some may be interested in how this ‘new’ information fits exactly the scenario in which I had accomodated Ardi; even down to the possibility that chimps and gorillas may have evolved fro a more upright-walking ancestor:

    My commments there also fit current ideas about the Caucasus H. erectus/H. habilis/Australopithecus fossils.

    Naturally I’m quite pleased with myself. Much of science involves using an hypothesis to make a prediction which is later proved. Of course I’m not surprised. My hypothesis was based on a huge amount of other evidence.

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