July 17, 2007 | David F. Coppedge

News Reporters Knuckling Under to Darwinian Storytelling

The science news media are virtually going ape over a claim about how chimpanzees might have evolved into upright-walking humans: what is going on?  It began with a paper in PNAS.1  Sockol, Raichlen and Pontzer measured the gaits of chimpanzees and humans and concluded that it is more efficient to walk upright than to propel oneself by knuckle-walking along the ground.  They began, “As predicted by Darwin, bipedalism is the defining feature of the earliest hominins and thus marks a critical divergence of the human lineage from the other apes.”  So their measurements seemed to support the idea that the cost of energy is what drove our imaginary forebears to gradually rise, stand up and walk.
    That was enough to send science reporters into a frenzy of headline writing:

  • PhysOrg said, “For early man, two legs better than four.”
  • News@Nature: “This chimp was made for walking.”
  • BBC News: “Energy use ‘drove human walking’”
  • Yahoo News (AP): “Humans walk upright to conserve energy…. ‘We think about the evolution of bipedalism as one of first events that led hominids down the path to being human.’”
  • National Geographic: “Humans beat chimps at walking efficiently…. anthropologists…get a glimpse of what drove the evolution of our bipedal stride.”
  • SciTech Today: “Humans Prove Genius with Bipedal Movement.”
  • Live Science: “Why We Walk Upright: Beats Being a Chimp…. According to this theory, the energy saved by walking upright gave our ancient ancestors an evolutionary advantage over other apes by reducing the costs of foraging for food.”
  • Science Daily: “Study Identifies Energy Efficiency As Reason For Evolution Of Upright Walking.”
  • Breitbart: “Why did humans evolve to walk upright?  Perhaps because it’s just plain easier.”
  • MSNBC News: “Why we quit aping around, began walking.”

In none of these stories did any reporter question the evolutionary angle.  They also failed to ask some of the obvious questions, among which might be: (1) If upright walking is so efficient, why didn’t the apes catch on for millions of years?  and (2) How could a desire to use energy more efficiently cause random mutations to appear so as to produce the multitude of anatomical changes involved?  Or, (3) Isn’t the assumption of energy cost leading to bipedalism a form of Lamarckism or orthogenesis, ideas long discredited?
    The original paper itself, in fact, did not address these questions.  Sockol, Raichlen and Pontzer only measured the energy cost of locomotion in modern humans and modern chimpanzees, assuming this was a determining factor in the rise of human bipedalism.  In their words, this was the extent of the investigation:

Here, we compare human and adult chimpanzee locomotor energetics and biomechanics to determine links among anatomy, gait, and cost.  Our study focuses on two primary questions.  First, do adult chimpanzees follow the pattern of costs found previously for juveniles?  Second, do differences in anatomy and gait between bipedal and quadrupedal walking, as well as between chimpanzees and humans, explain observed differences in cost?  Using this biomechanical approach to link differences in anatomy and gait to cost, we then examine what changes, if any, would lower the cost of bipedalism for an early hominin, such that bipedalism would be more economical than the ape-like quadrupedalism of the last common ancestor.

Thus, from the beginning, they merely assumed that there was an evolutionary “last common ancestor” of apes and humans, though no record of it exists.  This begs the question that humans evolved bipedalism from non-bipedalism.  Even so, in the end they admitted that their measurements could only in principle play some role in the story, not explain all the adaptations required for upright locomotion:

Our results, therefore, support the hypothesis that energetics played an important role in the evolution of bipedalismUnfortunately, a lack of postcranial evidence from the earliest hominins and their immediate forebears prevents us from testing the hypothesis that locomotor economy provided the initial evolutionary advantage for hominin bipedalism.  However, regardless of the context under which bipedalism evolved, our biomechanical analysis of adult chimpanzee costs, coupled with previous analyses of early hominin pelvic and hindlimb morphology, suggests that improved locomotor economy may have accrued very early within the hominin lineage.  Future fossil discoveries from the earliest hominins will resolve whether this energetic advantage was in fact the key factor in the evolution of hominin bipedalism.

Raichlen, one of the authors, won a runner-up for Stupid Evolution Quote of the Week with this short line: “We think about the evolution of bipedalism as one of first events that led hominids down the path to being human.”  William Jungers, the winner, topped this with: “Evolution needed a foot in the door, and we kind of got a snapshot of that here, which is kind of cool.


1Michael D. Sockol, David A. Raichlen, and Herman Pontzer, “Chimpanzee locomotor energetics and the origin of human bipedalism,” Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0703267104, published online before print July 16, 2007.

You have just seen another gratuitous, egregious, rambunctious, atrocious, nefarious, preposterous, loquacious, bodacious example of Darwin foot-kissing (cf. 11/19/2004).  Measurement of modern-day chimpanzees and humans has nothing to do with the evolution of upright posture, unless you already have sold your brain to the idea of evolution.  What does it mean?  Only that five chimpanzees, under artificially controlled conditions, spent a little more energy walking around on the ground with their knuckles than four human subjects did walking upright.  Big deal!  Guess what: chimpanzees spend much of their time climbing trees, for which they are well adapted.
    To get really rigorous here (as scientists are supposed to be), this study cannot really tell us anything about the entire population of chimpanzees or humans.  Why not measure a really fit monkey with a morbidly obese man?  Pygmy chimps vs marmosets and mandrills and orang-utans?  Tall people vs short people?  You cannot justify measuring five apes and four people on a treadmill and then making broad-brush generalizations about all apes and all hominins and all people for all time.  And you certainly cannot justify linking them historically through an unobservable process of evolution that happened once if at all, and cannot be repeated.  Why didn’t they ask Bonzo if he is envious of his human friends?  He seems pretty happy being all chimp.  He’s certainly more energy efficient moving about in the trees.
    To get an idea of how many major anatomical changes would be required to evolve upright locomotion, re-read our report on human endurance running.  What’s really disgusting is to see so many science reporters sucking up to Darwinian foolishness and spewing it out uncritically to the public, time after time.  Progress will only be made when science reporters acquire a new trait: an immaterial trait called courage.  Don’t expect it any time soon, though.  It requires intelligent design and purpose, and there’s a prerequisite: common sense.

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Categories: Dumb Ideas, Early Man

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