October 2, 2009 | David F. Coppedge

Step Aside Lucy; It’s Ardi Time

A new fossil human ancestor has taken center stage.  Those who love Lucy, the australopithecine made famous by Donald Johanson (and numerous TV specials), are in for a surprise.  Lucy is a has been.  Her replacement is not Desi Arnaz, but is designated Ardi, short for Ardipithecus ramidus – the new leading lady in the family tree.  Actually, she has been around for years since her discovery in Ethiopia in 1992.  It has taken Tim White and crew 15 years to piece together the bones that were in extremely bad condition.  But now, Ardi has made her debut and is stealing the limelight.
    The special issue of Science published this week had no less than 16 articles on this one fossil – an exceptional amount of coverage for any topic.  In the lead Editorial,1 Bruce Alberts proclaimed, “Darwin was certainly right” to predict that science would solve the mystery of human origins.  Popular science reporters, by habit, are going ape with “Read all about it!” headlines announcing the latest saga of human evolution.2  But wait – wasn’t Lucy the last word back in the 1970s?
    A completely new paradigm is emerging alongside the unveiling of Ardi.  The scoop is this: Lucy had nothing to do with our family tree after all.  She and her kinds were on a separate branch that did not lead to us.  In fact, all chimpanzees and great apes are now on different branches.  There goes a lot of storytelling.  The century and a half since Darwin commonly portrayed humans as higher up the family tree on a continuous lineage with chimpanzees our nearest living relatives.  Not any more.  Now we are to see all the great apes as highly-evolved (“derived”) mammals on separate branches from a more distant common ancestor that was probably more like small monkeys.  Getting tossed out with the housecleaning are some other popular notions: that humans came down out of the trees to hunt in the savannah (Ardi appears to have inhabited a woodland), and that hominids remained on the ground (it appears Ardi still had the feet for tree grasping).
    Most important, the new paradigm changes the mechanism of evolution itself.  In classical neo-Darwinism, traits evolve in a stepwise fashion through mutations and natural selection (the “referential model”).  Some evolutionists are now moving toward a more nuanced view called “adaptive suites.”  These are groups of traits that emerge together and evolve together as a package.  C. Owen Lovejoy (Kent State U) explained this idea in his Science article “Reexamining Human Origins in Light of Ardipithecus ramidus.”3  (Since reporting on all 16 articles about Ardi would be excessive, we will focus on this one article that surveys the broad issues.)  Before proposing his adaptive suite model, Lovejoy described how wrong all his predecessors had been:

An essential goal of human evolutionary studies is to account for human uniqueness, most notably our bipedality, marked demographic success, unusual reproductive physiology, and unparalleled cerebral and technological abilities.  During the past several decades, it has been routinely argued that these hominid characters have evolved by simple modifications of homologs shared with our nearest living relatives, the chimpanzee and bonobo.  This method is termed referential modeling.  A central tenet has been the presumption (sometimes clearly stated but more often simply sub rosa) that Gorilla and Pan are so unusual and so similar to each other that they cannot have evolved in parallel; therefore, the earliest hominids must have also resembled these African apes.  Without a true early hominid fossil record, the de facto null hypothesis has been that Australopithecus was largely a bipedal manifestation of an African ape (especially the chimpanzee).  Such proxy-based scenarios have been elevated to common wisdom by genomic comparisons, progressively establishing the phylogenetic relationships of Gorilla, Pan, and Homo.

Out with the old referential model, in with the new adaptive suites model:

An alternative to referential modeling is the adaptive suite, an extrapolation from optimization theory.  Adaptive suites are semiformal, largely inductive algorithms that causally interrelate fundamental characters that may have contributed to an organism’s total adaptive pattern.  One for the horned lizard (Phyrnosoma platyrhinos) of the southwestern U.S. serves as an excellent example (Fig. 1).  For this species, the interrelation between a dietary concentration on ants and its impact on body form imply, at first counterintuitively, that elevation of clutch size and intensification of “r” strategy (maximize the number of offspring by minimizing paternal care) are the ultimate consequences of this specialization.

So when we look at upright human bodies with all their specializations, we are to see them as suites of adaptations that evolved together out of some initial lifestyle change.  In the case of the horned lizard, some normal-looking lizard ancestor took on a taste for ants.  That made it consume more of its new prey because of the large amounts of chitin that had to be digested.  This, in turn, changed its body plan and made it more fat and sluggish.  Now it had to evolve armor (spines and horns) and camouflage for protection from predators.  So from one lifestyle change, a whole suite of adaptations evolved together.
    What, then, was the stimulus that made some unknown monkey begin its path to humanity?  Lovejoy looked at Ardi for clues.  The discoverers claim three traits stand out: (1) less sexual dimorphism (body size differences between males and females), although this is speculative; (2) reduced canine teeth; and (3) evidence Ardi walked upright (though this is disputed).  To him, this means the common ancestor changed its reproductive habits.  Sparing our readers the lurid details Lovejoy discussed about genitalia shapes and sizes, promiscuous behaviors and Darwinian concepts like “sperm competition” and “ovulatory crypsis”) he deduced that Ardipithecus had a suite of adaptations that would emerge in full flower in the human race – monogamy, straight teeth and upright stance.  Maybe it began as a sex-for-food deal.  This required explaining away some of the peculiar characteristics of male genitalia, but whatever: the adaptive suite is now the preferred explanatory model.  Along with the human adaptive suite came big brains, tool use, fire, language, spear-throwing, food hauling, hugging, and eventually, abstract mathematics and music.
    Lovejoy concluded that Lucy was an unfortunate detour in our understanding of where we came from:

Even as its fossil record proliferated, however, Australopithecus [Lucy and her friends] continued to provide only an incomplete understanding of hominid origins.  Paradoxically, in light of Ardipithecus, we can now see that Australopithecus was too derived—its locomotion too sophisticated, and its invasion of new habitats too advanced—not to almost entirely obscure earlier hominid evolutionary dynamics.
    Now, in light of Ar. ramidus, there are no longer any a priori reasons to suppose that acquisition of our unique reproductive anatomy and behavior are unconnected with other human specializations….
    When viewed holistically, as any adaptive suite requires, the early hominid characters that were probably interwoven by selection to eventually generate cognition now seem every bit as biologically ordinary as those that have also affected the evolution of lizards, frogs, voles, monkeys, and chimpanzees.  Comparing ourselves to our closest kin, it is somewhat sobering that the hominid path led to cognition, whereas that leading to Pan, our closest living relatives, did not, despite the near-synonymy of our genomes.

By closest living relatives, Lovejoy means close on different branches.  The old picture that they were closer down the same branch.  One notices that Lovejoy still employed the word “selection.”  That’s right; he is not abandoning Darwin.  “As Darwin argued, the ultimate source of any explication of human acumen must be natural selection,” he explained.  “The adaptive suite proposed here provides at least one evolutionary map by which cognition could have emerged without reliance on any special mammalian trait.”  Ostensibly this means that now evolutionists do not have to explain cognition by the sudden emergence by mutation of just one the “neural substrate” (big brain; see 09/24/2009).  Now they can employ the word “emergence” to an interwoven suite of adaptive traits that makes us human.
    The popular media are all echoing this line that chimpanzees are no longer on our branch of the family tree.  The image of Lucy’s famous skeleton has been supplanted by artwork from J.H. Matternes showing a hairy, upright female with Mona-Lisa-like cheeky smile.  Surely Johanson is not taking this sitting down, is he?  According to the U.C. Chronicle of Higher Education, he conceded that this fossil is “terribly important for all of our thinking” about human origins (emphasis on terribly), but “will undoubtedly generate widespread debate” in days to come.  The Chronicle added that the debate will include “the question of whether Ardi is actually a human ancestor.
    One point not emphasized in the popular reports is the fragmentary condition of the bones.  Casey Luskin of the Discovery Institute, writing for Evolution News and Views uncovered statements that the specimen was “crushed nearly to smithereens.”  The substrate was chalky and squished, resembling an “Irish stew” that would turn to dust at the slightest touch.  This included the critical pelvic bones necessary to establish whether the creature walked upright.  Six years ago, Tim White himself had cautioned fellow scientists that geological deformation of fossil fragments can produce misleading impressions of species diversity (03/28/2003).  Now it’s clear he was working on these badly-damaged Ardipithecus fragments at the time he said that (see, for example, 04/19/2006 and especially the 10/29/2002 and 09/23/2004 fights).
    In a second article for Evolution News, Luskin commented on the game-changing nature of this find.  Actually, Luskin pointed out, it’s another episode out of an old playbook – claiming that the new find “overturns the prevailing views on human evolution.”
    Perceptive readers may also take note of the fact that White dates Ardi at 4.4 million years BP (before present), while Johanson’s Lucy was found not far away and dated at 3.2 million years BP.  Some questions not being asked are (1) which way was evolution going for 1.2 million years between Ardi and Lucy, (2) how much did the landscape change geologically in that time, and (3) is it possible these species were contemporaneous.  Only Biblical creationists seem to be asking the other overlooked question: how can they prove those dates without assuming evolution?  For some creationist responses to Ardipithecus in particular and human evolution in general, see articles 1, 2, and 3 on CMI.

1.  Bruce Alberts, “Understanding Human Origins,” Science, 2 October 2009: Vol. 326. no. 5949, p. 17 DOI: 10.1126/science.1182387.
2.  A short list of popular reports: National Geographic News, Science Daily, Live Science, PhysOrg and the BBC News.
3.  C. Owen Lovejoy, “Reexamining Human Origins in Light of Ardipithecus ramidus.” Science, 2 October 2009: Vol. 326. no. 5949, pp. 74, 74e1-74e8, DOI: 10.1126/science.1175834.

OK, so Tim White is getting his 15 minutes of fame (see 04/27/2006).  If you have been following the Early Man stories in CEH for any length of time, you know the rivalries that exist between the fossil hunters.  Every year or so, as if on cue, the news media go berserk with euphoria over the latest human ancestor fossil, essentially declaring EYKIW (everything you know is wrong).  Rewrite the textbooks; all the stuff taught up till now has been overturned and revised by this latest fossil.  There’s the Leakey group, the Haile-Selassie Group, the Johanson group, the Spaniards, the Georgians and others, all competing for the spotlight.  With a successful media blitz comes speaking tours, book deals and fame.  The competition is especially effective when you can give a cute name to your fossil – Lucy in the Sky with Diamonds, Ardi, or Ida.  (Speaking of Ida, that attempt at EYKIW last May flopped badly – see 05/19/2009.  Even the shameless overboard paleoanthropology crowd thought that was a little too shameless and overboard.)
    If you enjoy comedy, read through the 271 Early Man stories we have published here over the last 9 years.  You see the playbook played out over and over again.  The latest contender promises that the new find “sheds light on evolution” and is helping us “understand our origins.”  Each time, numerous miracles are required to get humans their cognition and “unparalleled cerebral and technological abilities” (e.g., 03/29/2004).
    This time they are trying to forestall criticism with the sheer volume of words being written.  It’s like launching a hundred decoy missiles to get the enemy to waste all their interceptors.  You can go read all those papers if you wish, but there’s no sense in taking any of it seriously, because as we have pointed out repeatedly, it’s self-refuting nonsense to begin with.  If Tim White’s brain is a product of some ancient sex-for-food game played by Ardi’s genes, without her cognitive choice in the matter, then we have no way of knowing that Tim White’s brain is a product of some ancient sex-for-food game played out by Ardi’s genes.  Get it?  It undermines his whole reasoning apparatus.  We can’t believe a word he said.  His scenario crumbles to dust like Ardi’s bones.  If he really wants to reason, if he cares about finding the truth, then he has to abandon Darwinism and become a creationist.  Then he will have the causal resources to employ reason, logic, evidence and rhetoric – not until.
    What is most sad about all this is the deception to our young people.  How many of you were taught one of these tales in school?  Maybe it was Java Man (if you are getting into your senior years), or one of Louis Leakey’s National Geographic cover stories (if you are middle-aged), or Orrorin, Kenyanthropus, Toumai, Lucy or any number of other more recent tales.  The artwork is so deceiving.  Tim White cannot possibly know what that creature looked like in the condition those bones were in (don’t forget his statements from 2003).  Artists take the fragments and emphasize some traits and de-emphasize others to communicate the desired message, that this fossil has something to do with our origins.  The hair, the soft tissues, and the facial expressions are all imaginary.  National Geographic has been one of the worst offenders over the years.  The charts these people make up, placing each fossil into an artificial timeline and connecting dots between them, are just as bad.  Don’t trust any of it (e.g., 03/05/2004).   Would you follow one of these blind guides up ten floors of a house of cards so he can show you a steel girder he claims is holding up a ceiling, or a light fixture that is shedding light on a dark closet?  Their superstructure of paper, no matter how elaborate their origami, lacks substance.  What’s more, it sits on quicksand in a windstorm.  Get out of the away.
    It is alarming to look at old textbooks and NG mags and see how much revision there has been.  Paleoanthropology is not converging on a progressive, steadily-improving story coming into sharper focus.  It’s stanza after stanza of the EYKIW dirge.  Playing a dirge with a hip-hop rhythm doesn’t help.

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