Anthropology.net

Carol Ward1, William Kimbel, and Donald Johanson have published a paper in Science on the arch seen in a newly discovered fourth metatarsal of Australopithecus afarensis (AL 333-160). A lot of the popular press are publishing misleading headlines that this proves bipedalism in australopithecines. No, we’ve known they were bipedal — we just didn’t have a true idea as to what extent they were bipedal. So a find like this helps investigate the degree of bipedalism.

AL 333-160 left fourth metatarsal in dorsal, lateral, medial, plantar, and proximal views.

How does this tell us how bipedal A. afarensis were?

) Box plots of angular relations of the proximal and distal metatarsal ends to the diaphysis in chimpanzees, gorillas, humans, and AL 333-160.

If you’ve ever had the pleasure of visiting a podiatrist, you’d know flat feet are not conducive to bipedalism. The two-way arch helps support upright walking and distribute recoil force. Other great apes like, chimps and gorillas have flatter feet than us. The authors of this paper confirmed this by comparing the fourth metatarsal of chimps, gorillas, and humans to AL 333-160.

On all their comparisons, AL 333-160 fell within range of humans. There were some occasions where there’s a lot of gray area which I’ll address later. Nonetheless, to the right you can see the best comparison, in my opinion, which the comparison of the arch of the diaphysis of the bone between the two species. You can have a look at the rest of the figures here.

The problem I am seeing here is that this metatarsal is not Lucy’s (AL 288-1). AL 333 is designated to fossils from the site where the “First Family” came from and not the same  locality as AL 288. Nonetheless, they are not the same individual. Kimbel is quoted in the BBC News, saying,

“Lucy’s spine has the double curve that our own spine does,” Professor Kimbel said.

“Her hips functioned much as human hips do in providing balance to the body with each step, which in a biped of course means that you’re actually standing on only one leg at a time during striding.

“The knees likewise in Lucy’s species are drawn underneath the body such that the thighbone, or femur, angles inwards to the knees from the hip-joints – as in humans.

“And now we can say that the foot, too, joins these other anatomical regions in pointing towards a fundamentally human-like form of locomotion in this ancient human ancestor.”

This is a flawed association to make; a form of what I would call confounding bias. We don’t have Lucy’s 4th metatarsal to see what it looks like and unfortunately we don’t have the rest of the this specimens skeleton to say it looked like Lucy’s. In fact, we have very little australopithecine appendicular and skeletons other than AL 288-1 (most notable are AL 129-1 and STS 14). So how can Kimbel say that the foot joins other anatomical regions when we don’t know what the other regions really looked like?

See, the n of this sample is 1. Looking at the intervals in the figures, especially Fig 3 & 4, there a a significant amount of variation in humans and chimpanzees that overlap. Chimps aren’t bipedal but we are. So imagine you are a paleoanthropologist way in the future looking at one metatarsal of a now-current then-ancient chimpanzee way and comparing it to a humans — surely you could make the same conclusion as these three have. And herein lies the big issue with sensationalism… as is the problem often in paleoanthropology, we just don’t have many comparative samples but people want definitive conclusions.

Ward, C., Kimbel, W., & Johanson, D. (2011). Complete Fourth Metatarsal and Arches in the Foot of Australopithecus afarensis Science, 331 (6018), 750-753 DOI: 10.1126/science.1201463

Well, I feel somewhat vindicated. Remember the post where I criticized hominin cut marks from over 3 million years ago? Others have also had an eye of suspicion and have published their concerns in PNAS this week.

I was wrong in considering the croc marking differential to the cut marks. But I was not wrong in thinking they author of the original paper made the wrong conclusions. The authors of this new paper raise up an even more logical explanation, and carried out a more thorough analysis. Here’s part of their argument from the abstract,

“The Dikika research group focused its analysis on the morphology of the marks in question but failed to demonstrate, through recovery of similarly marked in situ fossils, the exact provenience of the published fossils, and failed to note occurrences of random striae on the cortices of the published fossils (incurred through incidental movement of the defleshed specimens across and/or within their abrasive encasing sediments). The occurrence of such random striae (sometimes called collectively “trampling” damage) on the two fossils provide the configurational context for rejection of the claimed butchery marks. The earliest best evidence for hominin butchery thus remains at 2.6 to 2.5 Ma, presumably associated with more derived species than A. afarensis.”

Trampling vs. Cut Marks (The image in A is courtesy of R. Blasco and J. Rosell. The images in B, D, and F are modified from McPherron et al.)

Looking back at the comment thread, I got a lot of flak. Aside from being wrong about the croc markings, I won’t deny that my post was inflammatory and incited a lot of the response. But many who know just a bit about the fossil and archaeological record, may find it extraordinary to believe australopithecines were using stone tools to extract food from flesh and bone from ‘indirect’ evidence. Of more concern was the lack of exhaustive exploration into other possibilities.

I remember as an anthropology undergrad one of my professors designed a hands-on experiment for us. If memory serves me correctly, this was for a zooarchaeology class. She acquired some beef bones from the local butcher and gave us stone tools. We were instructed to extract the marrow from the bones. We hammered the afternoon away.

Part of our assignment was to use different techniques and tools. We could cut, saw, abrade, chisel, etc. After the mess was done we compared our extractions from prehistoric samples. This comparative approach allowed use to systematically compare how we modified the bone to how possibly prehistoric individuals modified bone.

The authors of the current PNAS paper did something similar. The hypothesized that trampling could have created similar modifications as seen on the 3.39 million year old Dikika bones. And what did they do? Well they got some bone and experimentally setup some trampling experiments. As one would expect, cut marks would have a \/ shaped incision. Incidentally, the bones from Dikika show a \_/ flat bottom morphology. The authors write,

“Ninety-six percent of experimental trampling grooves display a broad-based, open cross-section with the aforementioned shape, versus just 4% of experimental grooves inflicted by simple (i.e., unmodified) stone flakes used to cut meat from bones. In addition, curvy and sinuous groove trajectories characterize nearly 70% of experimental trampling marks,compared with just 10% of experimental cut marks created with simple flakes (11). Together, these experimental results provide a robust actualistic context to evaluate illustrated marks F, G, H2,and I on DK-55–3 as high-probability trampling damage and not stone tool cut or percussion marks…”

I wonder what happened to good science?

What happened to the scientific method?

Did we not learn how to set up experiments and carry out analysis?

How can a paper make all the way into Nature and not exhaust all the possibilities?

These are not rhetorical questions. I am seriously asking it. I honestly feel that there is something rife in paleoanthropological studies lately. I must sound like a broken record to say yet again, too often are papers published in haste and for fortune and glory… All which compromise the validity & ethical responsibility of the science.

Domínguez-Rodrigo M, Pickering TR, & Bunn HT (2010). Configurational approach to identifying the earliest hominin butchers. Proceedings of the National Academy of Sciences of the United States of America PMID: 21078985

I don’t know who this is worse for, the editors & reviewers over at Nature or the authors of the article who can’t tell the difference between crocodile teeth markings and stone tool modification, nor raise the possibility. The paper, “Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia,” very confidently proclaims unambiguous evidence for,

“stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia, a research area close to Gona and Bouri. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access.”

Butchered by early humans or eaten by crocodiles? Image: David DeGusta

Given that the said rib fragment, DIK-55-2, came from a prehistoric lacustrine site. These markings could have been produced by crocodiles. Crocs, if you aren’t aware of (ahem editors and publishing group) are very abundant in the Rift Valley — both currently and prehistorically. On top of that, crocs like to eat meat and scavenge. Yes its true, they are carnivores. Australopithecines were at most ominivores, with wide based teeth useful in grinding tubers and nuts. Crocs have more meat shearing, bone crushing teeth than 3.39 million year old stone tools, which there are none of at the moment.

Given that there really isn’t an archaeological record for Australopithecine tools, I’ll take a gander and say crocs like to eat meat and scavenge more effectively than A. afarensis could make and use said tools to butcher a large ungulate. They have been on this Earth for roughly 197 million years more than hominins have and they are really good at what they do… Again, probably better than a species of hominins who did not live in the Stone Age. It is just as likely (if not more) that the markings were produced by crocodiles just given the ecological context.

Now just how different at cut marks from crocodile teeth marks? David DeGusta, from Stanford University, compared and contrasted the two different markings using images from Njau and Blumenchine (2006) paper titled, “A diagnosis of crocodile feeding traces on larger mammal bone, with fossil examples from the Plio-Pleistocene Olduvai Basin, Tanzania,” to those published in the current Nature article. I’ve inserted DeGusta’s image into this post on right for your own inspection. DeGusta was also on Science Friday, discussing this possibility, with one of the article’s authors, Zeresenay Alemseged. What do you think? Do they look completely different or similar? Seriously, I am asking you to comment. I’d like to know what you see.

Personally I don’t see much of a difference. I agree that stone tools marks are more V shaped, while croc teeth are more pitted/rounded. But take this into light: tool use, especially butchery, is a very human behavioral trait. In their search to attribute this human behavior to a primitive hominin species who roamed 800,000 years earlier, to the era of Australopithecus afarensis, without considering another possible explanation, the authors and editors of Nature were somewhat foolish.

Many paleoanthropologists are in this mad rush to claim their precious find is the most human of hominins, so as to etch their name into the textbooks in rewriting human evolution, that they sometimes forget about doing thorough comparative science. And many publications are in this mad rush to publish the most human of findings, that they sometimes forget about thoroughly editing scientific works. Think that could be the case? I sure do… Why should we settle on secondary evidence for Australopithecine stone tools when none have been found yet, and when another possibility hasn’t been extensively exhausted?

McPherron, S., Alemseged, Z., Marean, C., Wynn, J., Reed, D., Geraads, D., Bobe, R., & Béarat, H. (2010). Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia Nature, 466 (7308), 857-860 DOI: 10.1038/nature09248

That is what University of Liverpool’s Emma Nelson probably would have said if she were to meet our hominan ancestors in person. Known to hold true in anthropoids (humans, apes and monkeys), the index (second digit) to ring (fourth digit) fingers ratio or 2D:4D is an indication of how much an individual were exposed to androgen (such as testosterone) in the womb. The more androgen you are exposed to, the longer the ring fingers are (and the shorter the index fingers are compared to the index fingers).

Nelson et al. believe that a high ratio (longer index finger, shorter ring finger) suggests monogamy (or pair-bonded) while a low ratio (shorter index finger, longer ring finger) suggests polygamy (or non pair-bonded). Simply put, individuals with high androgen level is likely to be non pair-bonded and the telltale sign is in the index and ring fingers. Also, some controversial studies had suggested that both men and women who receive high levels of androgen in the womb are more likely to be stronger, faster, and more sexually competitive.

Nelson and her researchers recently looked at the fossils of two Neandertals and one Australopithecus afarensis with complete index and ring fingers to determine their 2D:4D. They found that Neandertals had long ring fingers, suggesting that they were polygamous just like modern day primates that live in groups. A. afarensis on the other hand, had long index fingers. Nelson is puzzled by this discovery. “These were small creatures that probably lived in groups and were being eaten by predators. How do you keep from mating with different members of the group?”, she said.

Indeed it does not make sense for A. afarensis to be monogamous if they live in groups. Notice that Nelson et al. only used one A. afarensis fossil to get the 2D:4D. Perhaps it is not their fault that only one A. afarensis specimen had complete index and ring fingers but such are the dilemma of using fossil specimens to generalize a whole species.The result might just be a statistical outlier. However, I can’t speculate the result or the implications but anyone that are familiar with statistical data knows that a small sample size leads to a higher sampling error. Also what would a 2D:4D = 1 (same index and ring finger length) be?

Interesting enough, John Hawks at John Hawk’s Weblog mentioned the correlation of 2D:4D with male homosexuality (Robinson and Manning, 2000). I would know about this. In fact, my 2D:4D is indeed low.  Robinson and Manning predicted right! Maybe …

I do find both Nelson et al. and Robinson and Manning (2000) research interesting but I would like to stress that the results are mere predictors and correlations. Take it with a grain of salt. Don’t go measuring 2D:4D of your future spouse, boyfriend or girlfriend and accuse them of not being monogamous or a homosexual.

Emma Nelson and her team presented their research at this year’s Society for Vertebrate Paleontology meeting held in Bristol, United Kingdom. Read more about Emma Nelson’s research.

References:

Reilly M. 2009. Human Ancestors Conflicted on Monogamy. Discovery News. Retrieved September 25, 2009, from http://dsc.discovery.com/news/2009/09/24/human-monogamy.html

Robinson SJ. Manning JT. 2000. The ratio of 2nd to 4th digit length and male homosexuality. Evolution and Human Behavior 21(5): 333-345. [doi:10.1016/S1090-5138(00)00052-0]

Originally posted on The Prancing Papio

It has been a while since I blogged anything on paleoanthropology. But once I saw John Hawks‘ post where he pointed out Elizabeth Culotta’s news piece in the latest Science on a new hominin femur from Galili, Ethiopia, I was excited. The femur was presented by Bence Viola to the Society of Vertebrate Paleontology, which meet for their annual get together about two weeks ago.

Galili, Ethiopia

Very recent argon-argon dating was done on, and Viola shared those to the Society. The bone is somewhere between between 4.38 million and 3.92 million years old. The bone indicates the individual was larger than lucy but isn’t complete. From what Culotta says, it seems as the distal end is broken off.

The anatomy of the head and neck of the femur suggest the owner was bipedal. But, the distribution of cortical bone around the femur is even. Arboreal primates have an even distirbution of cortical bone around the neck of the femora. The force of gravity and the weight of a bipedal individual causes a lot of stress on the lower half of the femoral neck. It has been observed that the cortical bone of femoral necks of bipedal hominids is thicker on the lower half, as a response to this stress. If you know anything about the debate between the Orrorin camp and the Ardipithecus camp, this should be all too familiar of a discussion.

I first read about hominid remains from Galili in this 2004 piece, which reported on the discovery of an almost complete lower right third molar (GLL 33) likely that of a male Australopithecus afarensis. Hawks pointed out a recent paper which describes the paleoecology of Galili — a open woodland to bushland ecosystem at a time when A. afarensis began replacing A. anamensis. So it is certainly possible that a semi-arboreal/bipedal hominids were navigating this terrain… But, Yohannes Haile-Selassie, who is also working on a 4 million years old hominid from Ethiopia, isn’t too convinced.

What do you think?

E. Culotta (2008). SOCIETY OF VERTEBRATE PALEONTOLOGY 68TH ANNUAL MEETING: Two Legs Good Science, 322 (5902), 670-671 DOI: 10.1126/science.322.5902.670b

Major kudos goes out to Simon of HENRY, who found this awesome shirt:

Even though that ain’t Lucy’s skull — she wasn’t found with a complete one… I still want one on these shirts!

Actually, I drew this skull in 2006!

The discussion about dimorphism between the sexes in the genus Australopithecus has been an ongoing debate in the world of physical anthropology and paleoanthropology. For many people interested in human evolution, this is an interesting question because sexual dimorphism can explain early mating systems.

I won’t get into that just yet, but I will overview some of the key points raised in the last 25 years with a specific emphasis on recent back and forth brouhah from two different camps. To start, in all honesty, I don’t know who really sparked the debate about investigating sexual dimorphism in early hominids, but I think it is safe to guess that it all happened after Lucy was discovered in the mid ’70′s.

One of the first traceable accounts of the debate started with one of my undergraduate professors. She introduced us to the questions she raised in the ’80′s about whether the different species of australopithecines are truly separate species or representatives of extremes in sexual dimorphism. At the time, and even now, a probability of this magnitude did not come without controversy. It got a lot of people talking about robust australopithecines being representatives of the male sex, whereas the more gracile ones are females. This consideration has been called going ‘beyond the orthodoxy’ by some.

Since then, a very thorough compilation of the debate was synthesized by Frederick Grine in the late ’80′s, who by the way, just recently put out a new revision of the text, “Evolutionary History of the “Robust” Australopithecines.” The debate has been going on still, but the general consensus fell in line with those made by Henry McHenry in 1992: Australopithecus afarensis was more dimorophic than modern day humans.

Much of the problem with the debate was that there just are not that many samples of australopithecines to reconstruct a good, statistically valid, understanding about the amount of variation in a population. That’s one of the biggest shortcomings in anthropology… the fact that we’re trying to extract as much information as possible from limited number samples. It is no fault of anthropology, that’s the nature of the research… When one finds a fossil, that’s basically all they find, a single fossil. We’d all like to find complete skeletons, but that’s rarely the case.

Furthermore, Australopithecus fossils do not come out from the same stratigraphic layer nor the same location. The fossils that do come out from the same layer and location, are most often not attributable to the same individuals (i.e. not from one definite skeleton). Nor are the fossils consistent in quality and composition of the physical fossil. In other words, the fossil record of Australopithecus, one of the more exhaustive collections in hominin species, is still not complete enough.

Enter the discovery of the A.L. 333 locality in Hadar, Ethiopia. What was unearthed at A.L. 333, is what people call the “First Family” of Australopithecus, an abundant but fragmentary collection of fossils from the same stratigraphic layer. The discovery was made from the same area where Lucy was found, and in the mid ’70′s, but it wasn’t published until the early ’80′s. The assemblage contained over 200 fragments of fossil bone with a minimum number of individuals at 9 and a maximum number at 22. Since they were all concentrated in the same stratigraphic layer and in close proximity, many consider the site a simultaneous death assemblage — basically a catastrophic event killed at least 9 early hominins in one fell swoop. This discovery seemed fulfill of the biggest shortcomings in analyzing Australopithecus, having a comparatively large collection of fossils from the same time, come from the same locality.

Fast forward to August of 2003, when PNAS published a paper that analyzed the dimorphism present in A.L. 333 collection. The title basically tells it all, “Sexual dimorphism in Australopithecus afarensis was similar to that of modern humans.” The authors made about 30 different measurements of bones from A.L. 333 and compared them to Lucy as well as the Makapansgat humeri. Unfortunately, because 9 complete skeletons weren’t found, the fossils used in the analysis are not all one anatomical element… rather, some are humeri, some are radii, others are femora, etc. The used the measurements from these different anatomical elements to make an estimation on the femoral head diameter, which is based off the best preserved Australopithecus afarensis femoral head, Lucy’s. This is called the template method, when a certain element is not represented in all the samples, so another element’s measurements that is present in the sample, is used to make a relative estimation about the missing element. To all you who live and breath statistics, this maybe a big bad faux pas — but really what else are you to do, make no analysis at all?

The authors of this PNAS paper extend their conclusion from the lack of dimorphism present in Australopithecus afarensis collection in A.L.333, to a discussion about a potential monogamous behavior in Australopithecus afarensis. In humans, the lack of a large dimorphism between males and females, is linked to monogamy. Why? Since human babies are born at a less developed stage and require more help and care to raise the baby, the males have lost their dimorphic stature while focusing on raising the baby. Without a large stature they aren’t able to harem up females that more dimorphic species like silverback gorillas have done. I’m not to sure I understand this linkage because it seems like one of those, “we don’t have empirical evidence but this story makes sense,” sorta situations.

These two conclusions irked the camp that want to think Australopithecus afarensis was largely dimporhic. And the most outspoken voiced their opinion in a 2005 issues of the Journal of Human Evolution. The paper, “Sexual dimorphism in Australopithecus afarensis revisited: How strong is the case for a human-like pattern of dimorphism?“John Hawks covered this two years ago, so I won’t rehash the points too much. In a nut shell, the authors of this slam the A. L. 333 study on several points, the primary one being that the A. L. 333 specimens represent males. They also raise questions about whether or not skeletal measurements, the only thing that can be analyzed from fossil remains, correlate with sexual dimorphism as well as if skeletal dimorphism can be used to predict social or behavioral features of primates. The authors were especially irked with prediction of monogamy due to the lack of dimorphism in the A.L. 333 samples.

The A.L 333 study offered up a quick and terse response that same year. Here’s the paper, “The case is unchanged and remains robust: Australopithecus afarensis exhibits only moderate skeletal dimorphism. A reply to Plavcan et al. (2005).” The authors address how skeletal dimorphism is only one aspect of size dimorphism, and how it can never tell us the total body size dimorphism by itself. About the monogamy claim, they clarify that no living primate model provides a basis to construct for A. afarensis sexual behavior, and therefore it is necessary to construct one. That’s why they merely raise the possibility that A. afarensis wasn’t exclusively, definitively polygamous, it coulda been monogamous as well as polygamous.

We’ve heard little about this debate since this 2005 cat fight. That all changed when this paper came out late last year in the American Journal of Physical Anthropology, “Strong postcranial size dimorphism in Australopithecus afarensis: Results from two new resampling methods for multivariate data sets with missing data.” The authors of this new paper offer up a really promising new methods to take out inaccuracies of estimating a missing measurement from another element. Furthermore, they take a multivariate analysis, which means more than one measurement which brings in more data that can be compared and scrutinized. They ultimately figure out that A. afarensis was as dimorphic as gorillas and orangutans.

I read this paper and man, I must admit, I have no idea what their two methods they are. I got so frustrated in making sense of out it. They claim their methods can compensate for inconsistencies using template method, but it just sings to me as an abstracted, obfuscated template method. Furthermore, if you wanna make sense of the method, maybe perhaps crunch out the numbers yourself, the authors provide you with this mind-numbing array of equations that I’ve uploaded to your right. I’m sorry if I can’t provide a more intelligible critique but really what are they trying to do — make their data so unapproachable that it can never be validated nor refuted? I’ve been told by many different professionals that if the data and the methods seems too complex, if they bring derivatives and calculus into to the fold, then something is fishy.

So the latest word is that A. afarensis dimorphism is similar to gorillas and orangutans — who’s male and female skeletons look like completely different species to the untrained eye! The jury is still out, there definitely seems to be two camps that are continually hashing this out, and until we find more complete comparable specimens, we’ll be reading this sorta stuff for a long time.

I do want to make a comment about where I stand on the issue. Like many others, I want to believe that A. afarensis was dimorphic… at least comparable to the levels seen in chimpanzee and bonobos. Why? Because, they are one of the earliest hominins we know of and have a lot of specimens of. Furthermore, from what we know of A. afarensis birth canal size and brain size, they weren’t as undeveloped as humans. Rather, they were born at similar developmental stages seen in chimpanzees. The argument that males lost dimorphism to help raise the kids doesn’t apply when we consider this fact. Now, the evidence from A.L. 333 tells us otherwise, and I trust that evidence because it comes from one stratigraphic layer and time. Furthermore, I trust the simple straight forward analysis on the A.L. 333. Not only does it come from a reputable source, Owen Lovejoy, perhaps one of the more preeminent biological anthropologists out there, but it also is followable — the statistical analysis, the data, the methods are clear and thorough.

Gordon, A.D., Green, D.J., Richmond, B.G. (2008). Strong postcranial size dimorphism in Australopithecus afarensis: Results from two new resampling methods for multivariate data sets with missing data. American Journal of Physical Anthropology, 135(3), 311-328. DOI: 10.1002/ajpa.20745

Lucy that little australopithecine which we also know as AL 288-1 is quite possibly the most popular fossil hominid known. Her remains have sparked lots of controversy lately, which shows how important and impactful this 3 million year old is to the field of paleoanthropology as well as popular culture. To feed into the pop culture craze, Norbert and Liberatore have created a graphic novel titled, “Lucy.” The site is in French and I don’t know French, so I can’t really give you more information other than that.

Judging from the sample pages the authors put up, the illustrations look very well done. The story line and page layouts remind me less of a graphic novel like Maus or Persepolis and more of the Marvell comics I read as a child. Curious to see an example? Check this one out.

I’ve read this summary of Donald Johanson’s visit to the Houston Museum of Natural Science to see Lucy, the 3 million year old australopithecine ‘he found’ about 33 years ago.

Lucy is also known as AL 288-1 or Dinkenesh, in Amharic, which means “You are beautiful.” The fossils are on a very controversial tour to US museums. While visiting Lucy, Donald Johanson summarized the rifts in paleoanthropology, he says anthropologists may disagree over some aspects of human evolution, but there is broad agreement on the basic theory of where it all began,

“The one thing that all anthropologists have agreed on now is that the fossil record for humanity is so convincing, from the very earliest, very primitive stages, long before Lucy, going back as much as six million years in Africa, that this is really the cradle of humankind, Africa.”

He also commented on creationist thought and answered some questions from high students who caught him while he was there. Here’s a sound bite,

I don’t like to read too much into some quotes, but sometimes I really must, especially when Johanson put something like this out there,

“The Afar people who live there today know what these bones look like and sometimes when we come back to the field, they will take me by my hand and they will walk me and say ‘look what I found when I was herding my goats.’ And they know that you should never pick it up, because then you do not know where it is from.”

In my experience one should never come out with a quote like this because it undermines one’s authority and ownership to the research. What happens when the locals know you want fossils and displace or destroy them? If you think that doesn’t happen, think again. It does. What happens when locals know you want a hominin and bring it to you, destroying the context? The fossil becomes useless… Why then is Johanson’s name on the publications? I can’t believe Johanson is quoted saying something like that, because it brings up the idea that he may have allowed such exceptions!