<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Roboto%3A300%2C400%2C500%2C700%7CRoboto+Slab%3A400%2C700">New Ardipithecus fossils shows creationists are wrong about Lucy (again)

Oh dear. This is one of the times I discover I’ve been spending too much time on the internet. Simpson et al. just found a bunch of new Ardipithecus fossils 1; and whilst everyone else is celebrating I’m left going “hehe, clearly creationists don’t know what they’re on about”

Which shouldn’t really be news to anyone, making the fact it’s my first reaction concerning. So come and cheer me up by suffering along as we take another dive into creationist wrongness.

Creationists and taxonomy

All of this stems from the fact creationists have a bit of a problem. You see, they have to draw a clear line between humans and other species that are “just an ape”; since we didn’t evolve from them. However, we did, making it impossible to cleanly divide us from other hominins.

Of course, being far removed from science hasn’t stopped them before; so they try anyway. The result is an entertaining variety of contradicting creationist claims about where species belong.

How creationists rank Homo naledi, highlighting the variety of contradictory positions caused by their unscientific approach. From the excellent Natural Historian.

In an effort to sure up their silly divisions, creationists will do their best to try and make those on the “just an ape” side seem as ape-like as possible. This can include selectively quoting the scientific literature to focus a species-ape like traits, to just flat out ignoring the science.

Lucy, sadly, has been a victim of the former; with Answers in Genesis depicting her as a knuckle-walker, despite the fact the evidence her species was bipedal is overwhelming. I’ve taken them to task on this before, prompting them to write a massive 6,000 word diatribe to refute lilol‘ me.

I’m not ashamed to say that being able to bask in their vitriol is one of my finest moments.

The reconstruction of Lucy from AIG’s creationist museum

Creationists and Lucy

Lucy herself contains abundant clues she wasn’t a knuckle-walker. However, one of the best lines of evidence actually comes from the rest of the hominin lineage. Namely, that none of them – including those creationists think are related to Lucy – contain any trace of knuckle-walking either2.

This makes their proposal not only wrong, but evolutionarily absurd. After all, knuckle-walking requires a suite of anatomical adaptations. All of these would have to evolve over time, leaving behind tell-tale clues in closely related species.

Anatomical adaptations for knuckle-walking missing in hominins

Except, as we’ve established, those anatomical traits aren’t present in other species. This means those adaptations would have to appear suddenly in Lucy’s species; and disappear again just as quickly.

This isn’t how evolution works, making the creationist model not only wrong; but biologically impossible. It’s like how flat earthers aren’t just wrong about the shape of the earth, their models violate all known laws of physics.

The cosmic egg model of flat earth, which postulates there are many earths being made in (and then expanding out from) the center. We live on a middle-ish one

Scientists and Ardipithecus

All of which brings us to Ardipithecus ramidus. They are one of the last hominin species that maybe could have knuckle-walked. There’s some good evidence they didn’t, but a lack of fossils prevent us being certain. Thus, they remain the last species giving the creationist claims (a tiny amount of) credibility.

Or at least, they were until palaeoanthropologists went and found more Ardipithecus fossils1.

The new discoveries come from Gona, Ethiopia, an area already famous for featuring fossil remains from more recent human species, and a whole bunch of stone tools made by them.

Now, the area gets another claim to fame as Simpson et al. spent nearly a decade surveying and excavating specific sedimentary deposits that are part of the Sagantole formation. They picked these because, at ~4.5 million years old, they’re the right age to contain more Ardipithecus1.

So if evolution, geology, radiometric dating etc. are actually reliable, they should discover many more fossils. Which, in a stunning testament to the fact science works, they did (which, on the flipside, is also a dramatic failure for the creationists, but let’s not be too mean here)1.

A map of Pliocene sediments (grey) and where Ardipithecus fossils were found

Across the Sagantole formation, Simpson et al. found nearly three dozen more Ardipithecus fossils. Individually, each might not be that impressive, but together they give us a surprisingly decent snapshot of the species1.

In particular, they preserve many features of the hand and wrist that should contain adaptations to knuckle-walking. Assuming, of course, the species did move like that.

Just some of the nearly 3 dozen new Ardipithecus fossils from Gona

Creationists and Ardipithecus

Crucially, this site is ~50 km away from earlier discoveries; and potentially 0.25 million years older. As such, it helps to expand our understanding of the natural variation within Ardipithecus. In this context, it can help reveal whether their apparent lack of knuckle-walking traits seen was a weird quirk present in just one individual, or the actual default condition of the species.

The answer is the latter, as I’m sure you’ve already guessed from the amount of sass I’m bringing to the table.

Notably, the new fossils preserve many bits of the hand and wrist, which are obviously key features involved in knuckle-walking. Containing, you know, the knuckles. Thus, if the species ever used it you can bet there should be evidence of it here. But there isn’t1.

A lovely bit of new Ardipithecus finger

Combining these new discoveries with existing finds, we can now definitively say that, compared to knuckle walkers1,3:

  • Their fingers are too short.
  • Has none of the prominent ridges or grooves for the relevant muscles to attach to.
  • A less robust palm, ill-suited to absorbing the forces of walking on it.
  • A weaker wrist, also poorly suited to walking on.

And of course, the best conclusion of all: creationists were wrong about Lucy (again).

References

  1. Simpson, S.W., Levin, N.E., Quade, J., Rogers, M.J. and Semaw, S., 2019. Ardipithecus ramidus postcrania from the Gona Project area, Afar Regional State, Ethiopia. Journal of Human Evolution129, pp.1-45.
  2. Lovejoy CO, & McCollum MA (2010). Spinopelvic pathways to bipedality: why no hominids ever relied on a bent-hip-bent-knee gait. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 365 (1556), 3289-99 PMID: 20855303
  3. Lovejoy, C.O., Simpson, S.W., White, T.D., Asfaw, B. and Suwa, G., 2009. Careful climbing in the Miocene: the forelimbs of Ardipithecus ramidus and humans are primitive. Science326(5949), pp.70-70e8.

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5 Comments

ashley haworth-roberts · 28th February 2019 at 5:37 pm

https://answersingenesis.org/human-evolution/hominids/did-ardi-head-up-human-evolution-before-lucy/
I see that as recently as 2014 Answers in Genesis were insisting that Ardipithecus ramidus must have been ”simply an extinct species of ape” and were doubting that it was bipedal when on the ground. Will they react to the new Journal of Human Evolution paper I wonder: https://www.sciencedirect.com/science/article/pii/S004724841730444X

    Adam Benton · 28th February 2019 at 10:51 pm

    I could see them getting around my criticisms by distancing Lucy et al. from all the other, clearly not knuckle-walking, hominins. So it would be interesting to see an updated comment, and where they’d place Ardi, Lucy etc. relative to all the other “just apes”

David Bump · 28th February 2019 at 10:41 pm

“This means those adaptations would have to appear suddenly in Lucy’s species; and disappear again just as quickly.” Not necessarily. This assumes that Lucy was indeed in the lineage that produced the later hominins/hominids. We know that all the extant great apes travel far more often and more comfortably on all fours (when not climbing trees). This leaves us with a very thin line of fossils possibly connecting us with ape ancestors and very little fossil material indeed for the equivalent ancestors of chimps, bonobos, gorillas, and orangutans. Quite possibly these knuckle-walking creatures descended from upright-walking apes such as… hmmm…

And it’s hardly surprising that after “nearly a decade surveying” an area merely “~50 km away from earlier discoveries” (less than 40 miles) that researchers managed to discover a whopping “nearly three dozen more Ardipithecus bones” (less than 36 out of hundreds in a full body, and aren’t a number the same parts of the body?) which appear to be mostly disarticulated, if not isolated, and sometimes fragmentary. This is still a very small sample, of poor quality, in a tiny geographical range, compared to many other fossil “species”*, including H. erectus and the Neanderthals. Still, kudos to the researchers for all their hard work in obtaining even that much.

Nor is it surprising that creationists can get things wrong — shall we throw out areas of science if we can point to a number of cases where scientists were wrong? And remember, science, especially this area of science, isn’t set in stone. Ideas about human ancestry have changed in the past, and some areas are still being re-evaluated and changing. So bask in vitriol if you get your kicks that way, but be careful about gloating too much.

*Considering living things are often subject to disputes about species identification and boundaries, fossil species’ identification should be considered rather precarious.

    Adam Benton · 1st March 2019 at 12:00 am

    You raise some good points, picking on threads I only talked about in passing and thus could stand to be addressed more thoroughly. So, here goes.

    For your first point, you wouldn’t just have to separate Au. afarensis from Ardipithecus, but from every other member of their genus; since every Australopith with sufficient skeletal material shows they were definitely not a quadruped (Au. afarensis also contains evidence on those lines, but since the museum went and built there stupid model in spite of that, I’ll treat it as a moot point). In this context, Ardipithecus is notable for being (a) basal to Australopiths and (b) having a low number of MNI represented in the fossil record. Thus, the possibility remained that the Ardi fossils found were unusual, and the species norm was quadrupedal with Au. afarensis representing an archaic holdover of that root form. This convoluted hypothesis is the only way the creationist model could make sense in the Australopithecus family tree, and these new fossils confirm it’s wrong.

    As for the second issue, about this apparently limited fossil sample, it’s worth remembering all these bones don’t come from the same skeleton. They were found at 13 different localities, spanning 3 strata and 2 sites. So, depending on how conservative you want to be, we could easily be looking at 3-13 different skeletons in this sample; which hopefully gives the scale of this discovery the justice it deserves. Granted, most of those skeletons are represented by fragments, but then they are very old. I’d like to see how well you hold after 4 million years :P.

    Finally, you are right that science is allowed to make mistakes. The issue here is that AIG is wrong on every level, from the anatomy of Lucy to parsimony to her family tree. And, crucially, they doggedly refuse to adapt to all this evidence. After all, to the best of my knowledge, that trash model of hers is still up in the museum. To me, this shows they aren’t driven by the evidence, but dogma.

Joe G · 1st March 2019 at 2:11 pm

Without the genetics that links the anatomical and physiological differences observed, you don’t have a mechanism capable of producing the transformations required. So that would be a problem.

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