If you love predictability, you've got to love the Discovery Institute. Whenever someone publishes a paper about human evolution, it's a pretty safe bet that someone there will soon take the time to explain how having learned something new means that we somehow know less than we did before. You can set your watch by it, almost.
The latest example comes from Casey Luskin. He "discusses" a paper that came out in Nature this week that reported on some fossils from Dmanisi, Georgia. Several skulls have been described from this site already, and the current paper focuses on post-cranial (less technically, non-skull) remains.
I'm not going to bother with a detailed, point-by-point rebuttal of Casey's claims. (See this post by Afarensis for that.) Instead, I'm just going to look at one of the more glaringly dishonest tactics that Casey used this time.
In his post, Casey discusses some of the information he got from a figure in the text:
According to the Figure 3 in the Nature report, the femoral length is like that of a human or a gorilla (Fig. 3b). The tibial mediolateral distal width is like that of a chimp, human, or bonobo. Figure 3a reports that the tibia length is quite similar to that of a gorilla but different from that of humans. (Figure 3 also reports the length of an arm bone, as the humeral length resembles that of a human or perhaps a chimp (Fig. 3b).) Finally, the fossil footbones that were discovered are reported have some features that are like human feet, and others that are closer to the feet of modern apes.
Casey's description of the information is accurate without being in any way an honest depiction of what the figure actually reports. Casey, you see, is discussing each axis of the graphs independently - first, he talks about femoral length, then about tibial width, then tibial length, and so on. It's no surprise that he finds that the fossil resembles humans in some respects and various apes in others. If you were to violate a recent grave, grab some bones, and repeat the analysis, you'd reach similar conclusions. The normal range for femoral length in humans is very similar to the normal range in gorillas; the normal range of humeral length for humans overlaps with the normal range in chimps and orangutans.
The authors of the paper reported the bone lengths for the fossil because they were looking at how those dimensions relate to each other. Their approach, unlike Casey's, makes sense. Humans have a very distinctive arm-to-leg ratio compared with the other great apes. Here's what part of the figure Casey was mining actually looks like. Figure 3b:
Legend: Stars, Dmanisi Homo; X, AL288-1 (Australopithecus afarensis); diamond, BOU-VP-12/1; triangle, KNM-WT15000 (H. erectus); Z, recent Homo sapiens; plus signs, Pan troglodytes; Y, Gorilla gorilla; squares, Pongo pygmaeus. (Legend and figure from Lordkipanidze, D. et al., 2007)
Looking at the figure, it seems that the picture isn't exactly as ambiguous as Casey was trying to pretend. Yes, you can say that the femoral length of the fossil falls within the normal range for both humans and gorillas. Yes, you can say that the length of the fossil falls within the normal range for both humans and chimps. Yes, saying both of those things without bothering to mention what the figure actually shows is dishonest.
Casey then turns around and uses his oh-so-careful interpretation of the graph to reach this conclusion about the fossils:
For those claiming this is clearly a species evolving into humans, a few troubling facts emerge from these data: This species lived millions of years after the supposed split in the lines that led to apes, and humans, respectively. I cannot be faulted for hoping that if there is an evolutionary story to be told here, this fossil would tell me whether it was evolving towards a modern ape, or a modern human. Yet these leg and foot bones in many respects resemble modern apes as much as they resemble modern humans. I cannot be faulted for being skeptical of the claim that these species were necessarily evolving towards modern humans. Is it possible these scientists are anthropomorphizing this find by assuming that it's evolving towards humanity?
Actually, Casey, you can be faulted for that claim. In fact, you should be. Not only have you taken some of the bone size data from the paper out of context to support your claim, you've also conveniently forgotten to mention a number of other pertinent facts. You didn't mention that this species had a very human-like arm-to-leg length ratio. You didn't mention that the fossils clearly show that the species walked upright. You didn't mention that there are skulls that are associated with the bones discussed in this paper, and that the skulls were analyzed in a separate paper. You didn't mention that some of the animal bones found at this site show tool marks, demonstrating that this species used tools to remove meat from the animals. I could go on, but the sheer tonnage of the things that you failed to mention in your efforts to obfuscate this paper is getting to be a bit much.
Reference:
Lordkipanidze, D. et al. 2007. Postcranial evidence from early Homo from Dmanisi, Georgia. Nature. Vol 449, pp305-310.
- Log in to post comments
More like this
I seriously doubt that BJB's Richard Leakey quote was from a 1990 PBS special, unless the special contained some old footage. There was a huge dust-up after Lucy was found in the late 1970's, when Leakey claimed (based on honest but flawed work) that 1470 was older than Lucy. Leakey eventually backed down, after his own crew --including, IIRC, Tim White and Basil Cooke-- told him the fossil evidence of related species indicated 1470 had to be younger than Leakey claimed it was. Further chemical, isotope testing of the dates proved that they were, indeed, too old.
You may be able to find more under "Kay Behrensmeyer," who I believe did the original flawed dating. (For which she doesn't deserve much censure. Apparently it was an unusually difficult geological stratigraphy.)
I'd like to point out that Richard Leakey, far from being the "world's foremost paleo-anthropologist" had no formal training in paleoanthropology. It seems very likely to me that if he had spent a few years in the brutally frank atmosphere of grad school, he might have been more reluctant to defend a shaky date.
I don't know if Leakey actually said what BJB claims he did, but if he did, it should be used as an example of how science has since moved on and corrected itself, not as a disproof of evolution.
Mike, can you provide a legend for the graph? I can't tell immediately which grouping belongs to which species. Especially the fossils in question.
Good idea. Added.
I'm guessing Casey also didn't post the figure itself. Or, if he did, he didn't include the caption. If he had, he might have been embarrassed to note that the Dmanisi fossil falls smack dab in the middle of the human range. I would think even a moron could figure that out.
I'm amazed that you can so arrogantly claim that you are absolutely right when even Richard Leaky humbly admitted in a 1990 PBS documentary that "If pressed about man's ancestry, I would have to unequivocally say that all we have is a huge question mark. To date, there has been nothing found to truthfully purport as a transitional species to man, including Lucy, since 1470 was as old and probably older. If further pressed, I would have to state that there is more evidence to suggest an abrupt arrival of man rather than a gradual process of evolving". Richard Leakey, world's foremost paleo-anthropologist, in a PBS documentary, 1990.
Bond, your quote mining Leakey misses the point namely that Luskin represents the data in a 'novel' way not necessarily supported by the actual data and/or paper.
Surely, while we can all accept that science may not have all the answers in this area, even though much has changed in the last 15 years, would you not agree that Luskin's 'arguments' deserve to be exposed for what they are?
Maybe "Flat-Earth Sherri" might be dumb enough to see the graph and draw the conclusions that Luskin did. I can't believe that Luskin is so rock-crushingly stupid to really believe his own explanation of the graph, but somehow I do find it quite believable that he is so prodigiously dishonest that he is willing to misrepresent it.
Casey Luskin-- "I cannot be faulted for hoping that if there is an evolutionary story to be told here, this fossil would tell me whether it was evolving towards a modern ape, or a modern human."
Good grief. No single fossil will ever tell us which way it's evolving. These fossils-- any fossils from a single individual or species-- can only capture a moment in the earth's history. So, naturally they won't tell us if that particular species was evolving towards apes or humans (or neither.) It's the whole accumulation of fossil evidence that shows that humans evolved from apes, not the other way round.
And Luskin must know that. He seems to have cut loose from any concept of honesty at all and simply says whatever he thinks will sell his program. He's become the vinyl-siding salesman of evolutionary theory.
So, "Bond, James Bond" are you going to give your actual source for the quote? All Google can turn up are anti-science sites (which all seem to be copying one another) and pro-science sites critiquing the claim.
I also found refs that point out that ER1470 has been re-dated. It's 1.3My younger than Lucy. See http://www.talkorigins.org/faqs/homs/specimen.html#habilis
AD HOMINEM: Bond, James Bond, maybe you should change your pseudonym. James Bond was always portrayed as an intelligent, quick thinking, open minded, fellow. You, on the other hand, do not seem to be possessed of these traits.
Beck, John Beck
P.S. -- Apologies to all(except one), but I just could not resist.
That figure is amazing, someone shd post it to PT directly, contrasted with Luskin's quote-mines!
Hm... I wonder what Luskin's Discovery Institute colleague, Michael Behe, will have to say about this, given that he apparently accepts common descent?
Holding my breath and waiting... waiting... waiting...
Bond, James Bond is sad, just sad.
Engaging Casey Luskin in debates on human evolution is tantamount to asking Michael Vick about the evolution of dogs. He might have some jaded insight, but the intelllectuality has already been rendered null and void.
Bond, James Bond wrote:
"I'm amazed that you can so arrogantly claim that you are absolutely right when even Richard Leaky humbly admitted in a 1990 PBS documentary..."
And I'm amazed that you would use a quote like that without providing an appropriate citation.
Does this documentary have a title?
Absolutely essential reading on Dmanisi from John Hawks:
http://johnhawks.net/weblog/fossils/lower/dmanisi/dmanisi_postcrania_na…
John argues that actually they weren't short at all, being a bit shorter than your average American and similar in size to prehistoric hunter gatherers. He also points out that one of the figures is wrong.
Bond, James Bond wrote:
I'm amazed that you [Mike Dunford] can so arrogantly claim that you are absolutely right ...
Dunford states that Casey used "glaringly dishonest tactics" and he supports that statement with abundant evidence. Dunford isn't arrogant, and he doesn't present a scientific position at all, much less claim that his scientific position is "absolutely right."
Mike, i would like to ask for a favor.
I love predictability, especially my General Predictability Model: Whatever you do, something will happen.
But I hate Discovery Institute (OK, I love it as a Comedy Center, but don't tell DaveScott, he may be able to ban me from my blog also).
Could you change the first phrase of your post to something like :
"If you love predictability, you may love the Discovery Institute", or,
"If you love predictability, you've got to love the Discovery Institute Comedy Center"
Please!
I tried a post earlier, which didn't go through. Richard Leakey may have said what BJB climed he did, but I doubt it was in 1990. There was a big dust-up over Leakey's claimed date for 1470, which Leakey's own team eventually proved was too early. I think Lucy was discovered c. 1976, so the date would have been something closer to 1980. In any case, Leakey's statement was based on faulty information; there is no reason to be quoting it years later.
Y'all, I grew up in Georgia, and I swear there is no town called Dmanisi. Unless that's near Valdosta.