The Discovery Institute recently published a book entitled Science and Human Origins that gives the ID take on human evolution. The book is authored by Douglas Axe, Anne Gauger (Both of the Biologic Institute), and Casey Luskin (from the Discovery Institute) From the book description at Amazon:
Evidence for a purely Darwinian account of human origins is supposed to be overwhelming. But is it? In this provocative book, three scientists challenge the claim that undirected natural selection is capable of building a human being, critically assess fossil and genetic evidence that human beings share a common ancestor with apes, and debunk recent claims that the human race could not have started from an original couple.
The book was reviewed in five parts by Paul McBride (starting here). This review created some defensive posts from the folks that created the book, but the dik-dik feces hit the fan when Carl Zimmer asked a simple question (be sure to read all four parts). Nick Matzke captured some of the fun over at The Panda’s Thumb. What caught my attention were the comments referring to the fossil record of human evolution, which prompted a defensive post by Luskin in which he promised to discuss the issue further in future posts. In the meantime he has excerpted several sections of his chapter in the book. In this post I will look at this excerpt. Note, I have ordered the book and will be reviewing Luskin’s chapter on paleoanthropology as soon as it has arrived and I have had a chance to read it. If this excerpt is any example, however, i will have to set my expectations pretty low.
Luskin starts things off by discussing White et al’s 2006 paper on Australopithecus anamensis:
What exactly was found? According to the technical paper reporting the find, the bold claims were based upon a few fragmented canine teeth which were said to be “intermediate” in size and shape. The technical description used in the paper was intermediate “masticatory robusticity.”60 If a couple of four-million-year-old teeth of “intermediate” size and shape make “the most complete chain of human evolution so far,” then the evidence for human evolution must indeed be quite modest.
Is this what the paper claimed? Well, no. Casey is playing fast and loose with the facts here. Here is what White et al described in their paper:
1. a left maxilla with fragmentary crowns of I2 and M2–M3, broken canine, premolar and molar roots, and adjacent palatal and lateral maxillary surface
2. a right maxilla contains the broken P4 root and damaged molar crowns
3. two associated dental rows
4. a metatarsal shaft without ends
5. an eroded distal foot phalanx
6. an intact intermediate hand phalanx
7. four vertebral fragments
8. an adult right femur shaft
So, did White et al base their claims on a few fragmented canines? No, they did not. True, a morphological and mathmatical analysis of the teeth (including premolars) did play a role the femur was just as important. Here is White et al on the femur:
One study predicted that when found, the Au. anamensis femur would be similar to that of Au. afarensis. Specimen ASI-VP-5/154 is approximately 75% of an adult right femur shaft preserving the base of the lesser trochanter and part of the neck–shaft junction. The shaft is well preserved except for its entire distal-most portion, lost just proximal to the popliteal surface. The shaft retains surface detail but is broken into slightly offset fragments that artificially accentuate the very slight (original) anteroposterior shaft curvature (in its original condition the shaft would have been much straighter). The shaft is remarkable for its thick cortex revealed throughout its length by the broken cross-sections.
A strongly roughened, .3-cm long (superioinferiorly), posterlaterally positioned attachment for m. gluteus maximus represents the most rugose part of the bone and contrasts sharply with the otherwise minimal relief of its shaft. There is no linea aspera, but only relatively blunt outlines of the adductor attachments both medially and laterally. At the shaft’s approximate midpoint, these two minimal ridges are separated by about 11 mm, a distance of considerable breadth given the probable original length of the bone. The Asa Issie femur is thereby similar to the ‘minimal linea aspera’ morphology of the posterolateral femur that characterizes the smaller A.L. 288-1 femur (Fig. 3). In this sense, the older Asa Issie specimen is on the presumably primitive end of the considerable range of variation in Au. afarensis with respect to this character. [Note: one reference omitted see below - afarensis]
Note that even though there is only 75% of the femur it still preserves diagnostic pieces of morphology that allow one to make statements about function and phylogeny. This concept escapes Luskin, for Luskin if a bone is fragmented it is a worthless blob. Note also that this femur allowed White et al to test a hypothesis published in a paper in 1999. The 1999 paper is by Carol Ward, Maeve Leakey, and Alan Walker and was published in Evolutionary Anthropology. In that paper, Ward et al survey what was known of the anatomy of Au. anamensis at that time (quite a bit actually). Concerning the femur they write:
There are, as yet, no femora known from A. anamensis, but in view of the fact that the A. anamensis tibia resembles those of A. afarensis in some detail, it would not be surprising to find that the femora of these two species were also similar.
So, to restate the obvious, based on a wide variety of fossil evidence an anagenetic relationship between Au. anamensis and Au. afarensis was hypothesized. White et al’s paper confirmed this hypothesis based on new evidence, subsequent papers, by Kimbel et al and Haile-Selassie, (see below for complete references) for example, have confirmed this relationship. Luskin mentions none of this, choosing instead to play fast and loose with quotes from White et al’s paper:
Accompanying the praise of this “missing link” were what might be called retroactive confessions of ignorance. In this common phenomenon, evolutionists acknowledge a severe gap in their evolutionary claims only after they think they have found evidence to plug that gap. Thus, the technical paper that reported these teeth admitted that, “Until recently, the origins of Australopithecus were obscured by a sparse fossil record,” 61 further stating: “The origin of Australopithecus, the genus widely interpreted as ancestral to Homo, is a central problem in human evolutionary studies. Australopithecus species differ markedly from extant African apes and candidate ancestral hominids such as Ardipithecus, Orrorin and Sahelanthropus.
Luskin has reversed the order of these statements. The part beginning “The origin of Australopithecus…” comes in the abstract while the part beginning “Until recently, the origins of Australopithecus… comes later in the paper, and the end of the sentence cites a paper by Asfaw examining the relationship between Au. afarensis and the robust australopithecines. Following which White et al list all the finds that have changed the the situation.
Then Luskin moves to Lucy and seems to be under the impression that Lucy is the only specimen of Au. afarensis available to us. Along the way he recapitulates material I have looked at previously here. He does add something new, which turns out to be a pretty good example of the intellectual dishonesty Luskin is known for. Here is where the dik-dik feces hits the fan. From Luskin:
There are some reasons for skepticism over whether the bones of “Lucy” represent a single individual, or even a single species. In a video playing at the exhibit, Lucy’s discoverer Donald Johanson admitted that when he found the fossil, the bones were scattered across a hillside, where he “looked up the slope and there were other bones sticking out.” Johanson’s written account explains further how the bones were not found together: “[S]ince the fossil wasn’t found in situ, it could have come from anywhere above. There’s no matrix on any of the bones we’ve found either. All you can do is make probability statements.”66
Sounds like Johanson is talking about Lucy at Hadar and is admitting that they just guessed where AL-288-1 came from right? Wrong! The 66 in the quote above is Luskin’s footnote which goes to:
[66.] Tim White, quoted in Donald Johanson and James Shreeve, Lucy’s Child: The Discovery of a Human Ancestor (New York: Early Man Publishing, 1989), 163.
So, it’s not Johanson talking about Lucy at Hadar, even though Luskin made it sound like it was. It’s Tim White talking about Lucy at Hadar, right? Wrong! If you go to page 163 of Lucy’s Child: The Discovery of a Human Ancestor you will find that it is Tim White talking about OH-62 at Olduvai Gorge!. The night previous to White’s statement Johanson, White, and Suwa had found the first few fragments of OH-62. The next day they returned to the area, which was also an area known as a dik-dik latrine, with a flock of scientists, students, and guests to begin a proper examination and excavation of the site. White is quizzing a couple of grad students on how to proceed when he makes that comment. So, rather than being a statement of ignorance about Lucy on the part of Johanson, it is just Luskin making stuff up it a blatant display of dishonest scholarship.
While on the subject of Lucy, Luskin seems to be under the impression the AL-288-1 is the only example of Au. afarensis we have. Kimbel and Delezene’s 2009 review paper catalogues several hundred specimens and more has been discovered since. Even without Lucy we have plenty of fossil material belonging to Au. afarensis.
Haile-Selassie (2012) Phylogeny of early Australopithecus: new fossil evidence from the Woranso-Mille (central Afar, Ethiopia). Phil. Trans. R. Soc. B (2010) 365, 3323–3331 doi:10.1098/rstb.2010.0064
Johanson and Shreeve (1989) Lucy’s Child: The Discovery of a Human Ancestor
Kimbel and Delezene (2009) “Lucy” redux: A review of research on Australopithecus afarensis. Yrbk of Physical Anthropology, Volume 140, Issue Supplement 49, pages 2–48. DOI: 10.1002/ajpa.21183
Kimbel et al (2006) Was Australopithecus anamensis ancestral to A. afarensis? A case of anagenesis in the hominin fossil record. Journal of Human Evolution 51 (2006) 134-152. doi:10.1016/j.jhevol.2006.02.003
Ward et al (1999) The new hominid species Australopithecus anamensis. Evolutionary Anthropology, Volume 7, Issue 6, pages 197–205. DOI: 10.1002/(SICI)1520-6505(1999)7:63.0.CO;2-T
White et al (2006) Asa Issie, Aramis and the origin of Australopithecus. Nature 440, 883-889. doi:10.1038/nature04629