Hominin Evolution Book Review: Bones of Contention (1987)

It has been a while since I posted on my blog and so out of guilt I’m back again to give you all a new post. This time I want to review a book published in 1987 on the political history of Palaeoanthropology. Written by biochemist Roger Lewin (1944 – Present) it charts the history of the science of Palaeoanthropology and is a must read for anyone interested in the origins of the genus Homo. In 1989, Lewin won the Royal Society Prizes for Science Books, for this very work. Many palaeoanthropologists at the top today could use with reading this book, to help them reflect on their own interaction with other workers in the field. The book was later revised in 1997, which at the time of posting was 21 years ago. There is no question that the field in need of an update to see if the field has changed or remained the same. I hope we will see this 3rd edition in the near future. Among other topics there is no doubt that the recent sexual misconduct of some scientists will need to be discussed in that new book. Let’s talk about the book. The title is very appropriate but when I first heard of it many years ago, I couldn’t help but bring out the immature side in me and snigger at the close similarity of the title with “Boners of Contentions”.  I pondered on the potential look of the T-shirt, I could have printed. Anyway, the book covers a number of important moments in palaeoanthropological history.

In no particular order, Lewin discusses the storm surrounding the Taung Child, Ramapithecus, the KBS Tuff, the famous Australopithecus afarensis A.L. 288-1 and finally the work of the Leakey, specifically the father and the son. Here we see human nature at its worst usually, particularly when we get emotionally invested in a fossil or hypothesis or even flawed radiometric dating. Human evolutionary research, whether the workers in the field, like it or not, is storytelling. Storytelling based on evidence, I might add, but it possesses shades of science fiction. The hominin fossil record is extremely fragmentary and the stories told by these fossils are also extremely fragmentary. They are necessarily weak and this is not particularly useful in a field, where the scientists develop emotional attachment to their pet hypotheses. Even in the light of new evidence many still ignore due to the embarrassment of admitting you are wrong, based on the new evidence. In Palaeoanthropology, admitting you were wrong has been virtually impossible. There is really only one recorded case of a straight up “I was wrong and someone else was right”, that honour goes to Arthur Keith and his review of Raymond Darts Taung Child.

The book allows me to reflect on my own strongly held convictions that Homo heidelbergensis is a valid taxon, at a time when palaeoanthropologists generally shy away from using it. I have imbued it with my own emotional attachment and will remain unconvinced that it should be invalidated. But equally, those who argue the latter, are blinded by their own biases. They do forget that the fossil record of the species is incredibly sparse, with only a handful of skulls representing it. Admittedly, they have a point regarding the Mauer Mandible as the holotype of the species. Ideally, the holotype should be a complete skeleton, but the early science of palaeoanthroplogy was not rigorous in how it proposed new species. So, we are stuck with a mandible in a hypodigm entirely of crania, you read right one mandible and a handful of crania. This, I would argue is no grounds to invalidate a species. In debates, the emotional investment, gets in the way of objective thought and they can get quite heated. Thankfully, I’m not the only palaeoanthropology student indulging in Pro-Heidelbergensis camp. In 2017, Roksandic et al., conducted a revision of the representatives of Homo heidelbergensis. Bones of Contention has allowed me to at the very least be aware of my flaws when it comes to interpreting the fossil record, but with the above paragraph, I’ve really only scratched the surface and it will require a separate essay on the topic for the future.

Bones of Contention is a well written book and while it loosely follows event chronologically, Lewin does compare and contrast most of the events, concluding with a theme that binds these momentous events together. The reminder that we are telling stories is the key thought all palaeoanthropologists should be aware of. I’m aware that the latter is quite a risky statement, but in order for the palaeoanthropology student to be as objective as possible, we need to keep reminding ourselves of that. Many at the top, I suspect, will laugh at this as obsurd. One could argue that the science is far more rigorous in every way today than the time Eoanthropus dawsonii was first unveiled to the world. The Humans that study the fossils, well they have not changed. We are still flawed scientists, whether we like to admit it or not. This is uncomfortable for me to say, but it is true. In the early 1900’s, scientists saw hominin evolution as a variation of the chain of being, a line from ancient apes to human’s, today a variation of multiregional evolutionism is the hip new hypothesis with the “river delta” as its logo.

One topic that the book does not cover is the nature of public engagement of palaeoanthropology contrasted with scientific process associated with palaeoanthropology. For me, these are two different worlds, incredibly incompatible and one scoffs at the other in righteous indignation. There will be no way to bridge the gap between the two. Yes, some seem to be bridging this gap, but if you really dig deeper, the reality is very different. Science is an ever shifting process of evidence evaluation, something that is incompatible with the requirement of certainty in the press. I often cringe at the often used phrase that “textbooks will have to be re-written on palaeoanthropology”. This comes as no surprise to any palaeoanthropology student, but this statement implies that palaeoanthropologists had figured out the evolutionary steps hominins took over the past seven million years to get to where we are today. Far from it and this is what angers a lot of palaeoanthropology students and lecturers. The media need a hook and unfortunately the most effective hook to draw the public in is the above statement. You can’t blame them for reaching as wide an audience as possible. But this has meant that palaeoanthropologists in particular are cautious when they engage with the media. The seemingly innocuous move to record conference talks on new scientific findings is very risky from the point of view of the speaker. Choice of words at a presentation on record and the choice of words on the academic paper may be subtly different but they have the potential to ruin the academic standing of the speaker. Additionally, journals have strict embargo rules on when engagement with the media can begin. Break these rules and the paper will never be published. There will remain a tension between these two worlds for many centuries to come. I hope that the 3rd edition of Bones of Contention will cover this in more detail than I have here.

The only criticism I have of the book is the placement of the black and white photographs in the book. It would be more beneficial to have them scattered throughout the book, associated with their appropriate chapters, instead of combining them together  in two groups in the centre of the book. This is not much of a criticism, but it does demonstrate the difficulty I had in my attempt to find one. It is an excellent book. To use a quote from Leonard to Sheldon in the Big Bang Theory, reading this book “is like looking into an obnoxious little mirror”. It help us re-examine ourselves and re-focuses our thoughts on a very controversial science.





Middle Pleistocene Homo naledi

John Hawks discusses the latest news on the Rising Star Project:

Africa’s richest fossil hominin site has revealed more of its treasure. It’s been a year and a half since scientists announced that a new hominin species, which they called Homo naledi, had been discovered in the Rising Star Cave outside Johannesburg.

Now they say they have established and published the age of the original naledi fossils that garnered global headlines in 2015. Homo naledi lived sometime between 335 and 236 thousand years ago, making it relatively young.

They’ve also announced the discovery of a second chamber in the Rising Star cave system, which contained additional Homo naledi specimens. These include a child and the partial skeleton of an adult male with a well-preserved skull. They have named the skeleton “Neo” – a Sesotho word meaning “a gift”.

The Conversation Africa’s Science Editor Natasha Joseph asked Professor John Hawks, a member of the team, to explain the story behind these finds.

To an ordinary person, 236 000 years is a very long time ago. Why does the team suggest that in fact, Homo naledi is a “young” species?

The course of human evolution has taken the last seven million years since our ancestors diverged from those of chimpanzees and bonobos. The first two-thirds of that long history, called australopiths, were apelike creatures who developed the trick of walking upright on two legs.

Around two million years ago some varieties of hominins took the first real steps in a human direction. They’re the earliest clear members of our genus, Homo, and belong to species like Homo habilis, Homo erectus and Homo rudolfensis.

Homo naledi looks in many ways like these first members of Homo. It’s even more primitive than these species in many ways, and has a smaller brain than any of them. People outside our team who have studied the fossils mostly thought they should be around the same age. A few had the radical idea that H. naledi might have lived more recently, maybe around 900,000 years ago.

Nobody thought that these fossils could actually have come from the same recent time interval when modern humans were evolving, a mere 236 to 335 thousand years ago.

How do you figure out a fossil’s age?

We applied six different methods. The most valuable of these were electron spin resonance (ESR) dating, and uranium-thorium (U-Th) dating. ESR relies on the fact that teeth contain tiny crystals, and the electron energy in these crystals is affected by natural radiation in the ground over long periods of time after fossils are buried.

U-Th relies on the fact that water drips into caves and forms layers of calcite, which contain traces of uranium. The radioactive fraction of uranium decays into thorium slowly over time. So the proportion of thorium compared to uranium gives an estimate of the time since the calcite layers formed. One of these calcite deposits, called a flowstone, formed above the H. naledi fossils in the Dinaledi Chamber. That flowstone helps to establish the minimum age: the fossils must be older than the flowstone above them.

For these two methods, our team engaged two separate labs and asked them to process and analyse samples without talking to each other. Their processes produced the same results. This gives us great confidence that the results are reliable.

What does the discovery of Homo naledi’s age mean for our understanding of human history and evolution?

For at least the past 100 years, anthropologists have assumed that most of the evolution of Homo was a story of progress: brains got bigger over time, technology became more sophisticated and teeth got smaller as people relied more upon cleverness to get better food and prepare it by cooking.

We thought that once culture really got started, our evolution was driven by a feedback loop – better food allowed bigger brains, more clever adaptations, more sophisticated communication. That enabled better technology, which yielded more food, and so on like a snowball rolling downhill.

No other hominin species could compete with this human juggernaut. You would never see more than one form of human in a single part of the world, because the competition would be too intense. Other forms, like Neanderthals, existed within regions of the world apart from the mainstream leading to modern humans in Africa. But even they were basically human with large brains.

That thinking was wrong.

Africa south of the equator is the core of human evolutionary history. That’s where today’s human populations were most genetically diverse, and that diversity is just a small part of what once existed there. Different lineages of archaic humans once lived in this region. Anthropologists have found a few fossil remnants of these archaic populations. They’ve tried to connect those remnants in a straight line. But the genetic evidence suggests that they were much more complex, with deep divisions that occasionally intertwined.

H. naledi shows a lineage that existed for probably more than a million years, maybe two million years, from the time it branched from our family tree up to the last 300,000 years. During all this time, it lived in Africa with archaic lineages of humans, with the ancestors of modern humans, maybe with early modern humans themselves. It’s strikingly different from any of these other human forms, so primitive in many aspects. It represents a lost hominin community within which our species evolved.

I think we have to reexamine much of what we thought we knew about our shared evolutionary past in Africa. We know a lot of information from a few very tiny geographic areas. But the largest parts of the continent are unknown – they have no fossil record at all.

Explorers Mathabela Tsikoane, Maropeng Ramalepa, Dirk van Rooyen, Steven Tucker (seated), and Rick Hunter (seated) inside the Rising Star cave system. Wits University/Marina Elliott

We’re working to change that, and as our team and others make new discoveries, I’m pretty sure we are going to find more lineages that have been hidden to us. H. naledi will not be the last.

The first Homo naledi discoveries were made in the Dinaledi Chamber. What led researchers to the second chamber? And what did you find there?

The Dinaledi Chamber is one of the most significant fossil finds in history. After excavating only a very tiny part of this chamber, the sample of hominin specimens is already larger than any other single assemblage in Africa.

The explorers who first found these bones, Rick Hunter and Steven Tucker, saw what the team was doing when they were excavating in the chamber. The pair realised that they might have seen a similar occurrence in another part of the cave system. The Rising Star system has more than two kilometres of mapped passages underground. In another deep chamber, accessed again through very tight underground squeezes, there were hominin bones exposed on the surface.

Our team first began systematic survey of this chamber, which we named the Lesedi Chamber, in 2014. For two years Marina Elliott led excavations, joined at times by most of the team’s other experienced underground excavators. They were working in a situation where bones are jammed into a tight blind tunnel. Only one excavator can fit at a time, belly-down, feet sticking out. It is an incredibly challenging excavation circumstance.

Geologist Dr Hannah Hilbert-Wolf studying difficult to reach flowstones in a small side passage in the Dinaledi Chamber. Wits University

The most significant discovery is a partial skeleton of H. naledi, with parts of the arms, legs, a lot of the spine and many other pieces, as well as a beautifully complete skull and jaw. We named this skeleton “Neo”. We also recovered fragments of at least one other adult individual, and one child, although we suspect these bones may come from one or two more individuals.

Is there a way for people to view these discoveries in person?

On May 25 – Africa DayMaropeng at the Cradle of Humankind World Heritage Site outside Johannesburg will open a new exhibit with the discoveries from the Lesedi Chamber and the Dinaledi Chamber together for the first time.

For people outside South Africa, the data from our three-dimensional scans of the new Lesedi fossils are available online.

Anyone can download the 3D models, and people with access to a 3D printer can print their own physical copies of the new fossils, as well as the fossils from the Dinaledi Chamber. It’s a great way for people to see the evidence for themselves.

Reprint from The Conversation

Three reasons the Cerutti Mastodon was not manipulated by hominins

A team of scientists recently announced an extraordinary claim that the 130,000 Cerutti Mastodon was manipulated by hominins.

“I have read that paper and I was astonished by it,” archaeologist Donald Grayson of the University of Washington. “I was astonished not because it is so good, but because it is so bad. Cracked bones and chipped stones at a fossil site might mean anything”, said Grayson. “It is quite another thing to show that people, and people alone, could have produced those modifications. The study doesn’t take that step, he said, “making this a very easy claim to dismiss.”

Gary Haynes of the University of Nevada Reno had this to say, “The paper states that the bones were being exposed by a backhoe. These pieces of heavy equipment weigh seven to fifteen tons or more, and their weight on the sediments would have crushed bones and rocks against each other.” When asked, Holen, the study leader, said that it “was very easy to tell the difference” between fractures made by stone hammers and those seen in bones crushed by bulldozers. He did not elaborate on how the differences manifest. “He’s pretty much dead wrong — there’s no definable difference,” Haynes said. A similar fossil dispute broke out in 2015 over a 24,000 year old mammoth in Maryland, he noted, shown to be fractured by heavy equipment. Also troubling, the “hammer” and “anvil” stones described in the paper don’t unequivocally look like tools, said Michael Waters of Texas A&M’s Center for the Study of the First Americans.

Michael Waters of Texas A&M’s Center for the Study of the First Americans noted that the “hammer” and “anvil” stones described in the paper don’t unequivocally look like tools. The study also runs afoul of the mounting genetic evidence, which indicates that the first people to reach the Americas and eventually give rise to modern Native Americans arrived no earlier than 25,000 years ago.”

1.6 Million Year Old Woman of Eastern Africa (2017 Review)

When fossil hunter Bernard Ngeneo came across the remains of this fossil, only the upper portion of the orbits were protruding from the ground. Excavation revealed one of the best preserved skulls of this time period, and one of the most striking early human fossils of any age.

KNM-ER 3733 represents a mature female of the early human species Homo erectus. The sex identification comes from a comparison of the anatomical features of her face with several other crania from Koobi Fora: KNM-ER 3883 (male), and KNM-WT 15000 (also male), found on the opposite side of Lake Turkana. The features of KNM-ER 3733 are markedly less robust. It’s known to be an adult on the basis of the cranial sutures (which were fully closed), the extent of the wear on the teeth, and the eruption of the third molars before the individual’s death.

How forensic science can unlock the mysteries of human evolution


People are fascinated by the use of forensic science to solve crimes. Any science can be forensic when used in the criminal and civil justice system – biology, genetics and chemistry have been applied in this way. Now something rather special is happening: the scientific skill sets developed while investigating crime scenes, homicides and mass fatalities are being put to use outside the courtroom. Forensic anthropology is one field where this is happening.

Loosely defined, forensic anthropology is the analysis of human remains for the purpose of establishing identity in both living and dead individuals. In the case of the dead this often focuses on analyses of the skeleton. But any and all parts of the physical body can be analysed. The forensic anthropologist is an expert at assessing biological sex, age at death, living height and ancestral affinity from the skeleton.

Our newest research has extended forensic science’s reach from the present into prehistory. In the study, published in the Journal of Archaeological Science, we applied common forensic anthropology techniques to investigate the biological sex of artists who lived long before the invention of the written word.

We specifically focused on those who produced a type of art known as a hand stencil. We applied forensic biometrics to produce statistically robust results which, we hope, will offset some of the problems archaeological researchers have encountered in dealing with this ancient art form.

Sexing rock art

Ancient hand stencils were made by blowing, spitting or stippling pigment onto a hand while it was held against a rock surface. This left a negative impression on the rock in the shape of the hand.

Experimental production of a hand stencil. Jason Hall, University of Liverpool

These stencils are frequently found alongside pictorial cave art created during a period known as the Upper Palaeolithic, which started roughly 40 000 years ago.

Archaeologists have long been interested in such art. The presence of a human hand creates a direct, physical connection with an artist who lived millennia ago. Archaeologists have often focused on who made the art – not the individual’s identity, but whether the artist was male or female.

Until now, researchers have focused on studying hand size and finger length to address the artist’s sex. The size and shape of the hand is influenced by biological sex as sex hormones determine the relative length of fingers during development, known as 2D:4D ratios.

But many ratio-based studies applied to rock art have generally been difficult to replicate. They’ve often produced conflicting results. The problem with focusing on hand size and finger length is that two differently shaped hands can have identical linear dimensions and ratios.

To overcome this we adopted an approach based on forensic biometric principles. This promises to be both more statistically robust and more open to replication between researchers in different parts of the world.

The study used a branch of statistics called Geometric Morphometric Methods. The underpinnings of this discipline date back to the early 20th century. More recently computing and digital technology have allowed scientists to capture objects in 2D and 3D before extracting shape and size differences within a common spatial framework.

In our study we used experimentally produced stencils from 132 volunteers. The stencils were digitised and 19 anatomical landmarks were applied to each image. These correspond to features on the fingers and palms which are the same between individuals, as depicted in figure 2. This produced a matrix of x-y coordinates of each hand, which represented the shape of each hand as the equivalent of a map reference system.

Figure 2. Geometric morphometric landmarks applied to an experimentally produced hand stencil. This shows the 19 geometric landmarks applied to a hand. Emma Nelson, University of Liverpool

We used a technique called Procrustes superimposition to move and translate each hand outline into the same spatial framework and scale them against each other. This made the difference between individuals and sexes objectively apparent.

Procrustes also allowed us to treat shape and size as discrete entities, analysing them either independently or together. Then we applied discriminant statistics to investigate which component of hand form could best be used to assess whether an outline was from a male or a female. After discrimination we were able to predict the sex of the hand in 83% of cases using a size proxy, but with over 90% accuracy when size and shape of the hand were combined.

An analysis called Partial Least Squares was used to treat the hand as discrete anatomical units; that is, palm and fingers independently. Rather surprisingly the shape of the palm was a much better indicator of the sex of the hand than the fingers. This goes counter to received wisdom.

This would allow us to predict sex in hand stencils which have missing digits – a common issue in Palaeolithic rock art – where whole or part fingers are often missing or obscured.


This study adds to the body of research that has already used forensic science to understand prehistory. Beyond rock art, forensic anthropology is helping to develop the emergent field of palaeo-forensics: the application of forensic analyses into the deep past.

For instance, we have been able to understand fatal falls in Australopithecus sediba from Malapa and primitive mortuary practices in the species Homo naledi from Rising Star Cave, both in South Africa.

All of this shows the synergy that arises when the palaeo, archaeological and forensic sciences are brought together to advance humans’ understanding of the past.

The above article was reprinted from The Conversation

The Siberian and the Laika Hunting Dog


Recently, I came across this early photograph of unknown origin. Confusion abounds online as to the origin and story behind it. After some time spent researching I ended up uncovering a dark past of Tsarist Russia. Siberia remained untouched by the outside world for many centuries, but that changed when the Ivan IV Vasilyevich (1530 – 1584) initiated a colonisation of Siberia beginning in July of 1580. This had disasterous concequences for the indigenous people who did not take to kindly to this subjugation. From 1706 to 1741, a series of Itelmen rebellions were brutally crushed, while the Koryak Rebellions of 1745 – 1756 marked a truly dark and bloody time in Siberian history. By about 1882, 12 indigenous groups were exterminated by the Russian Cossacks.

Yermak’s Conquest of Siberia (1895) – Vasiliy Surikov

In the midst of all this chaos, groups of ethnographers were making there way into these territories to record and document the way of life and the diverse languages of Siberia. We have four very important people to thank for this. Waldemar (Vladimir) I. Jochelson (1855-1937) and Waldemar (Vladimir) G. Bogoras (1865-1936) published many articles on the way of life of the Siberian peoples, as part of the famous Jesup Expedition . Waldemar Jochelson and his wife Dina Brodskaya, lived among the Koryak, Yukaghir, and Sakha (Yakut) peoples for nearly two years. Dina’s primary task was to prepare medical records and photograph life in Siberian, while she could do little to address the outbreak of measles. The Koryak people had abandoned their camp along the river Gizhiga to retreat up into the mountains with the reindeer. They suffered a 25% death rate thanks to the measles outbreak. Waldemar Bogaras and his wife Sofia lived with the Chukchee people who by 1900 had suffered a 30% drop in population thanks to the measles outbreak.

River Gizhiga

And this brings me to the second consequence of warfare between the Russian Co
ssacks and the indigenous Siberian people – epidemic outbreak. The Siberian population was decimated by measles and smallpox outbreaks over the three hundred years of warfare. It was Waldemar who documented the languages and folklore of the Chukchee.

It is likely that Dina Brodskaya took the photograph of the Yukaghir adult and the Laika hunting dog in the autumn of 1900. I cannot imagine the frustration of the team in carrying the heavy photographic equipment across the inhospitable siberian wilderness.

Major groups of eastern Siberia

The First Human Epidemic: Late Pleistocene Origin?

Current models of infectious disease in the Pleistocene tell us little about the pathogens that would have infected Neanderthals (Homo neanderthalensis). High quality Altai Neanderthal and Denisovan genomes are revealing which regions of archaic hominin DNA have persisted in the modern human genome. A number of these regions are associated with response to infection and immunity, with a suggestion that derived Neanderthal alleles found in modern Europeans and East Asians may be associated with autoimmunity. Independent sources of DNA-based evidence allow a re-evaluation of the nature and timing of the first epidemiologic transition. The paradigm of the first epidemiologic transmission, the hypothesis that epidemic disease did not occur until the transition to agriculture, with larger, denser and more sedentary populations, has been essentially unchallenged since the 1970s. Our views of the infectious disease environment of the Pleistocene period are heavily influenced by skeletal data and studies of contemporary hunter-gatherers. New genetic data – encompassing both hosts and pathogens – has the power to transform our view of the infectious disease landscape experienced by Neanderthals in Europe, and the anatomically modern humans (AMH) with whom they came into contact. The Pleistocene hominin environment cannot be thought of as free from infectious disease. It seems likely that the first epidemiologic transition, envisaged as part of the package of the Holocene farming lifestyle, may be fundamentally different in pace or scope than has previously been suggested. This paper demonstrates how high quality genomic data sets can be used to address questions arisingfrom the ecological context that shaped the co-evolutionary relationship we share with infectious diseases. We analyse the evidence for infectious disease in Neanderthals, beginning with that of infection-related skeletal pathologies in the archaeological record, and then consider the role of infection in hominin evolution. We have synthesised current models on the chronology of emergence of notable European disease packages and analyse what implications this evidence has for the classical model of the first epidemiologic transition. Using emerging data from Neanderthal palaeogenomics and combining this with fossil and archaeological information we re-examine the impact of infectious diseases on human populations from an evolutionary context. These palaeogeneticists argue that the first epidemiologic transition in Eurasia was not as tightly tied to the onset of the Holocene as has previously been assumed. There is clear evidence to suggest that this transition began before the appearance of agriculture and occurred over a timescale of tens of thousands of years. We suggest that the epidemiological transition was not, as has been thought since the 1970s, a phenomenon of the human shift to sedentary agriculture during the Holocene but a much older and more complex process that involved at least two species of humans. The origin of resistance to infectious disease has a much deeper timeframe and is highlighted by the ingression of Neanderthal DNA into modern human lineages. The transfer of pathogens between human species may also have played a role in the extinction of the Neanderthals. Our analysis of the genomes of archaic hominins provides evidence of pathogens acting as a population-level selection pressure, causing changes in genomes that were passed on to descendants and preserved in the genomes of modern Eurasians. the analysis of ancient genomes demonstrates that human behavioural patterns (in this case a shift to agricultural subsistence) should not be used as an ecological proxy to explain shifting trends in the co-evolutionary relationship between pathogens and human populations.

This work is available on BioRxiv: http://dx.doi.org/10.1101/017343

Acknowledgements: Rob Foley, Marta Lahr and the members of the Human Evolutionary Science Discussion Group at the University
of Cambridge. Funding for this research was provided by King’s College Cambridge and UCL.