Thursday, 29 May 2014

Human evolution favoured brain over brawn

Metabolite study demonstrates human muscle and brain tissue underwent disproportionate evolutionary change

A new study, published in the open access journal PLoS One Biology, has used metabolites to track evolutionary changes in brain and skeletal muscle tissues. Metabolites are metabolic products or intermediated of low molecular weight (1,500 amu or less), which are associated with the physiological processes that maintain the functionality of body tissues. Changes in the concentrations of these metabolites are thought to be closely related to evolutionary changes in the associated tissues.

Researchers measured the concentrations of more than 10,000 metabolites in the prefrontal cortex, primary visual cortex, cerebellar cortex, skeletal muscles and kidneys of humans, chimpanzees, macaque monkeys and mice using mass spectrometry-based techniques. They found that in most cases the differences reflected genetic distances between the species rather than environmental differences.

The striking exception was found in the human lineage. The concentration profiles of metabolites associated with the human prefrontal cortex, cerebellar cortex and skeletal tissues showed far greater changes than could be accounted for by genetic difference: by a factor of four for the brain tissue, and eight for the muscle tissue. In fact the muscle tissue is implied to have undergone more evolutionary change in the 6 to 7 million years since the divergence from chimpanzees than it did during the 130 or so million years separating mice from the common ancestor of the apes and Old World monkeys. No comparable differences were noted for the primary visual cortex or kidneys. Nor were significant differences to any of these results found after controlling for differences in diet and levels of physical activity.

It is well known that humans are physically quite weak in comparison to chimpanzees, despite weighing in at around twice the size. Surprisingly, this is largely based on anecdotal observations mostly predating the 1950s. Accordingly, the researchers set macaque, chimpanzee and human subjects a ‘pulling task’, which tested both upper and lower body strength. These tests confirmed the anecdotal observations.

The researchers concluded that the metabolic changes in human muscle tissue were associated with a drastic reduction in muscle strength; and that these changes might be linked to the changes in brain metabolism and enhanced cognitive abilities.

The findings are an extension of Aiello and Wheeler’s ‘expensive tissue’ hypothesis, which proposed that the considerable energy requirements of the human brain (around 20 percent of the total energy budget) could only be met by making savings elsewhere. Aiello and Wheeler (1995) proposed these savings were made by downsizing other energetically-expensive organs, principally the gut. Apparently, though, this was insufficient and further savings were required in the form of a decrease in the energy expenditure of skeletal muscle.


1.  Bozek, K. et al., Exceptional Evolutionary Divergence of Human Muscle and Brain Metabolomes Parallels Human Cognitive and Physical Uniqueness. PLoS One Biology 12 (5), e1001871 (2014).
2.  Aiello, L. & Wheeler, P., The expensive tissue hypothesis: the brain and the digestive system in human and primate evolution. Current Anthropology 36, 199-221 (1995).

Link (open access):

Sunday, 25 May 2014

The Venus of Willendorf

The Venus of Willendorf is a small 11.1 cm (4 3/8 in) high figurine carved from oolitic limestone and tinted with red ochre.

The 25,000-year-old figurine dates to the Gravettian period and is one of the most iconic artefacts of the European Upper Palaeolithic. It was discovered in 1908 by archaeologist Josef Szombathy near the village of Willendorf in Austria, and since then it has resided in the Naturhistorisches Museum, Vienna. It is currently on display in the Mineralogy galleries, having been relocated there while the Prehistory galleries undergo refurbishment. I took the photographs of the front, side and rear views when I visited the museum during a recent trip to Vienna. From a personal point of view, the enigmatic figurine did much to spark my interest in prehistory, so I was very keen to see it in person for the first time.

With its large breasts, full figure and exaggerated sexual characteristics, the contrast between the Venus of Willendorf and the classical portrayal of the Roman goddess could not be greater. Yet there is nothing crude or primitive about its execution; it is immediately obvious that the figurine is as finely-worked as anything from classical times.

The face is concealed behind rows of plaited hair, which comprise seven concentric bands surrounding the head, with two more semi-circular bands below at the back of the neck. Another interpretation is that the figurine is wearing a woven fibre hat.
Female figurines with similar attributes are known dating to throughout the European Upper Palaeolithic, though most are from the Gravettian period. Despite its obvious inaccuracy, the term ‘Venus figurines’ has been used to describe them since the first examples were found in the nineteenth century. They are often interpreted as fertility figures or mother goddesses, although their real function remains unknown.

Thursday, 15 May 2014

13,000 year old skull and mtDNA reinforces continuity between Paleoindians and Native Americans

Teenaged girl ‘Naia’ shared craniofacial features with earliest-known Americans, but genetic profile is common among today’s Native Americans 

The first people to reach the New World arrived around 15,000 years ago, having migrated across the Beringia land bridge that then linked Siberia to Alaska. The Paleoindians, as they are known, possessed craniofacial features that differ markedly to those of present-day Native Americans. Their skulls were long and narrow, the face narrow and the forehead prominent. By contrast, present-day Native Americans are broad-faced, with rounder skulls. A facial reconstruction of Kennewick Man – an 8,400 year old skull found in the Columbia River, Kennewick, WA – is said to bear startling a resemblance to the actor Sir Patrick Steward.

It has therefore been suggested that there were two migrations to the New World, with the Paleoindians arriving first and later being replaced by the ancestors of the present-day Native Americans. However, others argue that the differences arose in situ, possibly as a result of changes in diet when the Paleoindians adopted agriculture during the period between 8,000 and 2,000 years ago. Another possibility is that the changes are simply the result of genetic drift.

The ‘two migrations’ theory has received a significant setback with the recovery of a near-complete human skeleton of a female aged 15 to 16 years from Hoyo Negro, a submerged collapsed chamber in the Sac Actun cave system in the Yucatan Peninsula, Mexico. The skeleton has been nicknamed ‘Naia’ (Greek for ‘water nymph’), and it has been dated to between 12,000 and 13,000 years old. Naia’s craniofacial features are typical of the Paleoindian morphology, but mitochondrial DNA extracted from a molar teeth has been identified as belonging to the haplogroup D1, which occurs only among present-day Native Americans. This is consistent with the view that there was continuity between Paleoindians and present-day Native Americans.

Researchers now intend to sequence Naia’s nuclear DNA, which they hope will shed further light on the origins of the first Americans.


1. Chatters, J. et al., Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans. Science 344, 750-754 (2014).

Friday, 9 May 2014

Rice versus wheat agriculture could explain cultural differences within China, claim researchers

Greater interdependency found in rice-growing regions

People living in the rice-growing regions of southern China are more interdependent, loyal, and nepotistic, and less likely to divorce than their counterparts in the wheat-growing regions north of the Yangtze, according to a study published in the journal Science.

Han Chinese students from various regions in the country underwent a series of tests, including the ‘triad task’, which shows subjects lists of three items, such as train, bus, and tracks. They then decide which two items should be paired together. Two of the items (trains and buses) can be paired because they belong to the same category (trains and buses are forms of transport), and two (trains and tracks) because they share a functional relationship (trains run on tracks). Participants from rice-growing regions were more likely to pair the train and the track, whereas those from wheat-growing regions tended to pair the train and the bus.

The so-called ‘rice theory’ is an extension of subsistence style theory, which argues that some forms of subsistence (such as farming) require more functional interdependence than other forms (such as herding). Over time, societies that have to cooperate intensely become more interdependent, whereas societies that do not have to depend on each other as much become more individualistic. Previous studies have tended to focus on farming versus herding rather than differences between types of farming.

The two major differences between farming rice and wheat are irrigation and labour. Rice paddies require the construction and maintenance of elaborate irrigation systems, in turn requiring cooperation between farmers – often at village level. Farmers also need to coordinate their use of water so as not to adversely affect the supplies of their neighbours. Overall, growing paddy rice is at least twice as labour intensive as wheat farming.

The rice theory predicts that a Unus pro omnibus, omnes pro uno mentality will apply to anybody living in a region where rice has been farmed for thousands of years, not just those directly involved with its production. This prediction was borne out by the study, as few if any of the participants had actually farmed rice or wheat for a living.

My feelings are that while this is an interesting study, one should always be cautious about cultural determinism.


1. Talhelm, T. et al., Large-Scale Psychological Differences Within China Explained by Rice Versus Wheat Agriculture. Science 344, 603-608 (2014).


Thursday, 8 May 2014

Study traces origins of Neolithic in South Asia

Eastward dispersal from Southwest Asia was slower than that unto Europe

A new study, published in the open-access journal PLoS One, has considered the eastwards spread of agriculture from Southwest Asia. This has been less well studied than the westwards expansion into Anatolia and Europe.

Researchers conducted a statistical analysis of radiocarbon dates for 160 Neolithic sites in western and southern Asia. The locations of these sites suggest that the dispersal of farmers eastwards from the Zagros followed two routes: a northern route via northern Iran, southern Central Asia and Afghanistan, and a southern route via Fars through the interior of southern Iran.

Analysis of the radiocarbon dates indicated an eastwards expansion at an average speed of 0.65 km per year, rather slower than the 1 km per year documented for Europe. The authors of report considered this to be unsurprising. Firstly, the arid climate and complicated topography of the region are less favourable for agriculture. Because of this, the early Neolithic settlements in Iran were relatively small and widely separated. Secondly, the European expansion was aided by the Danube, the Rhine and the Mediterranean coastline, but there are no major rivers in Afghanistan or Iran that could play a similar role.

The authors were encouraged that the fairly simple ‘wave of advance’ model used captured the salient features of the data studied, but stressed the need for a more detailed analysis that would consider local environments and climatic conditions.


1. Gangal, K., Sarson, G. & Shukurov, A., The Near-Eastern Roots of the Neolithic in South Asia. PLoS One 19 (5), e95714 (2014).


Wednesday, 7 May 2014

How to think like a Neandertal, by Thomas Wynn and Frederick Coolidge

Of all early humans, none have captured the public imagination to anywhere near the extent of the Neanderthals. Indeed, with the possible exception of the dinosaurs, no extinct species is so deeply rooted in our popular culture. The idea that tens of thousands of years ago, people very much like ourselves shared the planet with another human species is one that intrigues many, although the term ‘Neanderthal’ is all too often used in a pejorative sense, and there is a widespread perception of the Neanderthals as dimwits.

In this engaging and accessible book, which is nevertheless as rigorous as any textbook, anthropologist Thomas Wynn and psychologist Frederick Coolidge paint a very different picture of the Neanderthals and their way of life. Drawing on archaeological and fossil evidence, they go beyond reconstructing the Neanderthal world and attempt to deduce their underlying thought processes.

In the first chapter, we are given an introduction to the world of the Neanderthals. From the start, Wynn and Coolidge refer to the Neanderthals as ‘people’, which is entirely correct as they were every bit as human as we are. The name comes from Neander Tal (‘Neander Valley’) near Dusseldorf, where Neanderthal remains were first identified in the 1850s (it was originally spelled ‘Neander Thal’, hence the more commonly-used spelling, but it has always been pronounced ‘tal’ and not ‘thal’). We learn that the Neanderthals were short, stocky, powerfully-built folk, with chinless, protruding faces, pronounced browridges over their eyes, and long, broad noses. The braincase was long and low, rather than the globular shape of modern people. Many features of their distinctive anatomy were adaptations to the harsh conditions of Ice Age Europe, but in comparison to very early humans it turns out that modern people are actually far more distinctive than Neanderthals.

An important difference is the shape of the braincase, which reflects the actual shape of the brain itself. Neanderthal brains were differently shaped to ours, and about ten percent larger. Does this mean that they were ten percent smarter than us? Wynn and Coolidge believe that they were neither more nor less intelligent than us – just different. This conclusion provides a focus for the rest of the book.

Neanderthals lived hard and died hard. Shanidar 1 lived in Iraq about 50,000 years ago, and was in his late 30s when he was killed by a rock fall. But long before his death he had suffered a number of major injuries, any one of which could have killed him. He owed his survival to caring companions, who nursed him back to health – and a dogged ability to cope with pain and life-changing injuries. Nor was Shanidar 1 particularly unusual: the pattern of healed injuries suffered by Neanderthals is very similar to those suffered by rodeo riders, suggesting that were regularly pitted against large, dangerous animals.

Each subsequent chapter focusses on a different aspect of Neanderthal life, and uses the evidence to build on this initial picture of them as tough but compassionate folk. Topics include hunting, spear making, family life, burial traditions and language. Wynn and Coolidge even examine Neanderthal humour before characterising them as pragmatic, stoical, risk-taking, empathic (in that they cared for their sick and injured), hard-hearted (in that they were prepared to leave the sick and injured behind if they needed to move camp), conservative (from the point of their extremely static technology, not their voting intentions), and xenophobic (in that they rarely met strangers and distrusted them when they did).

The final chapter plays a game of ‘Trading Places’ and speculates how a Neanderthal might fare in our modern world, and how a modern human in theirs. Wynn and Coolidge suggest that Neanderthals would do well in our world, and would excel as doctors, mechanics or soldiers. On the other hand, they suggest that a modern human would struggle to make a go of Neanderthal living.

The demise of the Neanderthals is covered fairly briefly. The arrival of modern humans in Ice Age Europe is viewed from the Neanderthal perspective. It is surmised that the end came when the climate began to deteriorate 30,000 years ago. This had happened before, and the Neanderthals had able to cope – but now they had competition. The modern humans were more adaptable and inventive when it came to finding new sources of food and developing new hunting methods. The Neanderthals retreated south to the Iberian Peninsula, where they held out for a while, but in the end they died out.

Wynn and Coolidge suggest that the Neanderthals may survive as dim cultural memories. Possibly some European folk traditions have their origins in ancient encounters with Neanderthals. More plausibly, they also suggest that our enduring fascination with the Neanderthals is that they were humans who led very different lives to ourselves, yet were still somehow like us. The Neanderthals live on as “inexact mirrors of ourselves”, Wynn and Coolidge conclude.

How to think like a Neandertal, by Thomas Wynn and Frederick Coolidge is published in the USA by Oxford University Press © 2012

Tuesday, 6 May 2014

The engraved ochres of Blombos Cave

World’s earliest abstract art

Seventy-three thousand years ago, an elderly man sat in the mouth of a limestone cave, intently working on a small rectangular piece of reddish-brown ochre. From time to time, he paused in his work and stared out towards the sea that lay a kilometre away. First he scraped and ground the piece flat on two sides and then, with the aid of a sharp stone tool, he engraved a cross-hatched geometrical design upon one of the newly-ground facets. It was the second such piece he had made, but there would be no others because a few weeks later he fell ill with a respiratory disease. A younger man would probably have recovered, but at 48 he was old and worn out. Within a few days, he was dead.

When his companions eventually decided it was time to move on from the cave that had been their home for the last six months, they took most of their few possessions with them. But the old man’s ochres were forgotten and left behind. Within a few months, the ochres and all other traces of the brief occupation were buried beneath wind-blown sand, and they would not see the light of day again for very long time indeed….

In actuality, we have no idea who engraved the two pieces of ochre found at Blombos Cave in 2002, and although it is likely that they were both the work of the same individual we cannot be certain. The cave is located on the southern coast of South Africa in a limestone cliff 35 m (115 ft.) above sea level, 100 m (330 ft.) from the coast, though when occupied the coastline was further away. Discovered by archaeologist Christopher Henshilwood, it is one of the most extensively researched sites from the African Middle Stone Age.

Henshilwood has been familiar with the site since his childhood, since it is located on land owned by his grandfather. As a boy, he found a number of artefacts, dating from comparatively recent prehistoric times. In 1991, he returned there as a PhD student, hoping to discover similar artefacts. Instead, he found a number of bone tools and stone points that dated from a far earlier period, over 70,000 years ago.

After completing his PhD at the University of Cambridge, Henshilwood obtained funding to commence excavations at Blombos Cave, and he continues to lead work at the site to this day. Three Middle Stone Age phases of occupation have been identified. These are known as M1 (73,000 years ago), M2 (subdivided between an upper phase 77,000 years ago and a lower phase 80,000 years ago) and M3 (125,000 years ago). Each phase contains a number of occupation layers, but they are quite shallow indicating that the cave was only occupied sporadically and for relatively short periods of time.

However, while the cave was in use its occupants enjoyed a varied diet of large fish, shellfish, seals, dolphins and land mammals. Mole rats were often roasted over a fire and eaten; these large burrowing rodents are considered a delicacy by local farm workers to this day. The later occupations of the cave are associated with the Stillbay tool industry, which has first identified in the 1920s and named for the village of Still Bay, which lies a short distance from Blombos Cave.

The Stillbay was one of the cutting-edge industries of the African Middle Stone Age, and was noted for its finely-worked leaf-shaped stone points, which were made from high-quality materials including chert, quartzite and silcrete. The Stillbay people also made and used bone awls and projectile points, similar to those seen in ethnographic collections. Such implements are far more difficult to manufacture than stone tools. Other examples of Stillbay high tech included compound adhesives for hafting stone points to spears, and the use of heat treatment and pressure flaking for finishing stone artefacts. The Stillbay industry was widespread, and not confined to the region around Blombos Cave and Still Bay. Curiously, however, it was short-lived and persisted for less than a thousand years, before being replaced by seemingly less advanced industries of the type more typical of the African Middle Stone Age.

Perhaps the most important discovery at Blombos Cave has been the engraved ochres. Ochres are a range of minerals containing iron oxide that exist in a range of colours including red, yellow, brown and purple. They have long been used as pigments and their first known use was at least 266,000 years ago at Twin Rivers, a complex of caves in southern Zambia – before the appearance of modern humans. It is possible that the Twin Rivers ochre was used for utilitarian purposes, such as for making adhesives, for medicinal purposes, hide processing, or even as Stone Age sunblock. However, the consistent selection of brightly-coloured and often hard to grind materials suggests an ornamental explanation such as for body painting. In South Africa, red ochre appears in the archaeological record from at least 160,000 years ago, and invariably material with the reddest hues seems to have been preferred – again suggesting a non-utilitarian purpose.

Several thousand pieces of ochre have been found at Blombos Cave, and in 2002, Henshilwood reported the two pieces of engraved ochre from the 73,000 year old M1 phase, which were catalogued as AA 8937 and AA 8938. Both had been engraved with cross-hatched patterns, using a sharp stone tool to make wide grooves upon surfaces previously prepared by grinding. On AA 8938, in addition to cross-hatching, the pattern is bounded top and bottom by parallel lines, with a third parallel line running through the middle. The fact that the two pieces are so similar suggests a deliberate intent, rather somebody absent-mindedly scratching away at the pieces with a sharp object. Somebody who knew just what they were doing must have sat down and engraved the two pieces. Other engraved ochres were later identified, although they were less spectacular than AA 8937 and AA 8938. They came from all three phases of the site, and some were over 100,000 years old.

The Blombos Cave ochres are central to the debate about the emergence of modern human behaviour, which anthropologists define as the ability of humans to use symbols to organise their thoughts and actions. Symbols are anything that refers to an object or an idea, and can take the form of sounds, images or objects. They may refer directly to an object or idea, for example a representational image; or they may be totally abstract, such as spoken or written words. Thus for example a drawing of a cat, the sound ‘cat’ or the written letters ‘c-a-t’ may all be used to refer to a cat. We use symbols all the time – whenever we read a newspaper, check the time, consult a map or admire a painting or sculpture. All of these activities involve symbolic behaviour: human society could not function without it. Modern syntactical language is a system of communication that uses symbols in the form of spoken and (in the last six thousand years) written words to enable an effectively infinite range of meanings to be conveyed.

The earliest human species such as Homo habilis and Homo erectus are thought to have had only a very limited ability to use symbols, but it is hotly debated when the fully symbolic behaviour of present-day people emerged. Was it shared with some archaic humans – in particular the Neanderthals – or was it limited to Homo sapiens, emerging at the same time as anatomical modernity around 200,000 years ago? Some go further and argue that even Homo sapiens lacked behavioural modernity until about 40,000 to 50,000 years ago. Proponents of this view believe that a behavioural ‘Great Leap Forward’ occurred at this time as a result of a favourable genetic mutation that rewired the brain and enabled syntactical language and other trappings of behavioural modernity to develop.

They base this view around the observation that artefacts that are unequivocally the products of modern thought processes – cave paintings, figurines and carvings – do not appear in the archaeological record until that time. But Henshilwood argues that the engraved geometrical patterns on the ochres imply the existence of modern syntactical language, and that modern human behaviour must therefore have emerged much earlier.

Henshilwood dismisses other possible explanations for the marks on the ochres. For example, he claims that they could not the by-product of testing for the quality of powder that could be obtained from the ochres, as only a few lines would be required for this purpose. He also believes that the marks are unlikely to have been the result of absent-minded doodling because great care was taken in completing the patterns and ensuring the incisions matched up. Furthermore, engraving lines on hard pieces of ochre requires full concentration in order to apply the right pressure and keep the depth of incision constant. He believes that not only were the marks on the ochres made with deliberate intent, but recurring motifs on ochres found in all three of the Middle Stone Age phases are evidence of a tradition of engraved geometric patterns that began more than 100,000 years ago and persisted for tens of millennia.

The most obvious question is what was the significance of the geometric patterns? Henshilwood notes that the Christian cross would appear equally abstract to somebody unfamiliar with religious iconography. It is possible that the patterns meant something quite specific to the people who made them, though just what we simply don’t know and probably never will know.

Another question is if humans were able to produce abstract art over 100,000 years ago, why was figurative art not seen until so much later? One possibility is that humans were still not behaviourally fully modern and were not at this stage able to make figurative images, though Henshilwood rejects this possibility. He notes that there are many cultures that do not make figurative art, and many others that do so using perishable materials that would not survive for tens of thousands of years.

Henshilwood believes the fact that the ochre engravings were intentionally created and depict distinctive geometrical patterns is enough to demonstrate that they are the product of a society of behaviourally-modern humans. Given the evidence for technological sophistication during the Stillbay period, we should not find this unduly surprising.

Photo credit:

Image copyright held by author, Chris Henshilwood
Photo by Henning (2007)
Webpage available at:
Licence: CC by Share Alike 3.0 unported

Monday, 5 May 2014

Comment on Villa & Roebroeks (2014) ‘An Archaeological Analysis of the Modern Human Superiority Complex’.

A paper by Paola Villa and Wil Roebroeks ( 1) in the open access journal PLOS ONE has reviewed archaeological evidence for the view that the ‘inferiority’ of Neanderthals to modern humans was responsible for their demise. See this post for a quick summary.

Villa and Roebroeks are critical of view that comparisons between the archaeological records of the African Middle Stone Age and European Middle Palaeolithic can be used to demonstrate that Neanderthals were ‘inferior’ to modern humans in terms of a wide range of cognitive and technological abilities, and have made a very good case.

However, they seem to be dismissive of the impact of what they describe as ‘subtle biological differences’ between Neanderthals and modern humans, which they state ‘tend to be overinterpreted’. They cite Pearce, Stringer and Dunbar (2013) as an example.

Pearce, Stringer and Dunbar used eye socket size as a proxy for the size of the eye itself and showed that Neanderthals had larger eyes than modern humans. This is not an unexpected result; living at high latitudes, Neanderthals experienced lower light levels than people living in the tropics, and larger eyes might have been an evolutionary response. The consequence is that in comparison to a modern human brain, a greater proportion of the Neanderthal brain might have needed to be dedicated to the visual cortex, with the trade-off that less was available for other cognitive functions. Pearce, Stringer and Dunbar suggested that Neanderthals were less able than modern humans to maintain the complex social networks required to manage long-distance trade networks effectively, and learn about the existence of distant foraging areas unaffected by local shortages. Furthermore, their ability to develop and pass on innovations might have been limited in comparison to modern humans ( 2).

On a less subtle level, it is only to be expected that the neural organisation of the Neanderthal brain would have differed from that of modern humans. The globular brain case of Homo sapiens differs from the long, low braincase that characterised archaic human species, including Neanderthals, and the change reflects a change in the actual proportions of the brain. In comparison to archaic humans, the parietal lobes of modern humans are expanded, and these are associated with the processing of speech-related sounds ( 3, 4). It is possible that their development played a role in the development of syntactic language in Homo sapiens and that Neanderthals used different and partially non-verbal forms of communication ( 5).

While Villa and Roebroeks have demonstrated the risks of over-reliance on archaeological evidence, the biological differences between Neanderthals and modern humans are real. These differences must be included within a holistic approach to understanding the cognitive abilities of the Neanderthals, who as we now know are far from extinct in that they live on in the genome of modern populations.


1. Villa, P. & Roebroeks, W., Neandertal Demise: An Archaeological Analysis of the Modern Human Superiority Complex. PLoS One 9 (4), e96424 (2014).
2. Pearce, E., Stringer, C. & Dunbar, R., New insights into differences in brain organization between Neanderthals and anatomically modern humans. Proceedings of the Royal Society B 280 (1758) (2013).
3. Wynn, T. & Coolidge, F., in Rethinking the human revolution, edited by Mellars, P., Boyle, K., Bar-Yosef, O. & Stringer, C. (McDonald Institute, Cambridge, 2007), pp. 79-90.
4. Coolidge, F. & Wynn, T., The Rise of Homo sapiens (Wiley-Blackwell, Hoboken, NJ, 2009).
5. Mithen, S., The Singing Neanderthal (Weidenfeld & Nicholson, London, 2005).

Sunday, 4 May 2014

Academic publishing: a case study

Humans: from the beginning is a single-volume guide to the whole of the human past, from the first apes to the first cities (for more information, go to It took me nearly five years to research and write, and my intention was to release it initially as an eBook on the Amazon Kindle platform (I may eventually also release it as a print-on-demand paperback but currently have no plans to do so). To produce an eBook from my source files was certainly not going to be a trivial task – the work as a whole ran to around 250,000 words in 32 chapters, together with an introduction and a number of maps, infographics and plates and illustrations. In addition, each chapter was comprehensively referenced. Although not a textbook as such, Humans: from the beginning draws extensively on journal articles and other academic literature, and each source used was properly cited using Harvard-Anglia referencing.

In this post, I will document the steps I took to turn my source files into an eBook meeting the same standards of production values and professionalism as an academic book produced by one of the major publishing houses. Please note that the work is a case study rather than a comprehensive guide. Obviously no two books are alike, and not all the material here will necessarily be relevant to your needs. Conversely, you may find that some of your needs and questions are not directly addressed. If so, however, there should be enough material here to point you in the right direction. Please also note that a basic knowledge of HTML and CSS is assumed.

Becoming a micropublisher
The basic questions I needed to address were:
1. How to ensure that my self-published eBook was as professional in its production values as any produced by a major publishing house;
2. Mastering the basics of producing an eBook for the Kindle platform;
3. How best to use the eBook format to provide ease of access to the roughly 1,500 academic sources my book cited;
4. How else I could take advantage of the eBook format by offering features not available in a traditional book;

The importance the first of the above cannot be overstated. We live in a world in which self-publishing has finally come of age, liberating authors from the often frustrating task of trying to persuade publishers and/or literary agents to take them on. However, they now face a fresh set of problems in that they now have sole responsibility for tasks that could once be left to their publishers. The author is now in effect a micropublisher, and if they do not achieve the same standards of professionalism as a larger-scale publisher their work – however good – will be unlikely to be taken seriously.

The first and most obvious requirement for a book is a good book cover. This should not be daunting; my book featured a stone hand-axe superimposed on a horizon over which dawn is breaking. The breaking dawn represents the long, slow rise of our modern world; the hand-axe is a stone tool of a type that remained in use more or less unchanged for one and a half million years. In many cases, things need not even be that complicated. For this work I selected a simple textured background, available from the Amazon Cover Creator.

The next step was to obtain an ISBN Number for my book. Although this is not obligatory for an Amazon Kindle book, I felt it would be advisable. Large-scale publishing houses do not release books without ISBN numbers, as a micro-publisher I wanted to do the same. In the UK, ISBN numbers are the responsibility of the Nielsen ISBN Agency (please note that their site is a bit temperamental with some browsers). The minimum purchase is a block of ten numbers for a price of £132.00 inclusive of VAT. This might sound like overkill, but bear in mind that if do intend to release your book as a paperback as well as an eBook, you will require an ISBN number for each format. Academic non-fiction is frequently re-issued as new editions, each of which will also require a fresh ISBN number.
You also need to give a name to your publishing house. Note that this is a purely a label and not a limited company: you do not have to register anything with Companies House. However, you do need to choose a name that does not conflict with that of any other publishing house. It is also advisable to steer clear of names suggesting an association with well-known organisations or individuals. “Beckham Books” might sound catchy, but unless you happen to share your surname with the former England footballer it is probably best avoided. A Google search should confirm whether your chosen name is likely to be acceptable, but Nielsen has the final say.

I also registered web domain names for my book title and for the name of my publishing house. I set up a promotional website for the book: this is a fairly straightforward non-self-hosted WordPress blog; the web domains  and both redirect to it. The site itself features a brief biography of the author (i.e. myself), a preview extract and links to where the book may be purchased on and (it’s worth noting that although I’m a UK-based publisher, the bulk of my sales have been in the United States).

Intellectual Property
Fail to respect the intellectual property of others and solicitor’s letters could start landing on your doorstep.

As noted above, my work was fully referenced in accordance with standard academic practice. I was also sparing in my use of exact quotes, preferring where possible to paraphrase. Exceptions were made when the quote was obviously intended by its author to be humorous; there I was careful to fully-attribute the quote in writing in addition to providing a citation. Although I did not do so in my book, be aware that quoting lines from songs or printed matter that are not out of copyright will require permission from the copyright holder.

My book included a number of photographic images and here I was careful to either i) obtain the permission of the copyright holder, or ii) ensure that it was available for use under Creative Commons. In the first instance, I actually used only one image which was licensed for use at a very reasonable fee. In all cases, I provided full attribution, identifying sources and copyright holders, with details of the relevant Creative Commons licences where applicable. A caveat is that you can come across items that should not have been listed under Creative Commons, for example photographs that have been taken in museums and other places where photography is not permitted or is for personal use only (the same applies, of course, to any photographs you might take yourself).

eBook Basics
Pretty well any of the remarks above could be applied to traditional books as well as eBooks, but before going any further into the details of how I converted the finished manuscript of Humans: from the beginning into an eBook, here is a very brief introduction to eBooks and how they differ from printed books. An eBook is a book-length electronic document comprising text and images that is readable on a computer, mobile device or dedicated e-reader (such as the Amazon Kindle). Many eBooks are electronic versions of printed books, but many (including mine) do not have a printed counterpart. Though many would argue that eBooks lack the charm of printed books, they do have a number of advantages. The most obvious is that large numbers of eBooks can be stored on a device no larger than a single printed book.

Other important advantages are:
1. An eBook does not require an index, as all text is searchable. To somebody like myself, who constantly needs to look up items in reference books, printed indices are a constant source of frustration as time and time again what I am looking for is either not in the index at all, or a listed page (often the only one) contains absolutely no reference to the required subject matter (the printed book equivalent of the dreaded 404 Not Found message). Furthermore, you can only look up subjects. If you want to look up a phrase you happen to remember as part of the text you want to find, there is no way to do so.
2. Navigation within an eBook is quick and easy. Instead of referring to the Contents for the page number of the desired chapter and then turning to that page, you can be taken there at a single click. While this might not seem like a big deal in itself, in a non-fiction eBook the same approach can be used to provide easy access to references, glossary items and visual matter.
3. The reader of an eBook is not stuck with the publisher’s choice of font and can select from a number of fonts. Text size, page colour, margin size and line spacing are also reader-selectable. It is actually possible for the publisher to mandate the choice of font in an eBook, but Amazon discourages the practice and I did not do so.
4. An important difference between a printed book and an eBook is that in the latter, the concept of the page number is completely meaningless. The amount of text displayed at any one time on an e-reader will depend on a) the physical size of the device and b) the choice of font size selected by the user.
There are two major eBook formats, the open EPUB standard and Amazon’s in-house MOBI/KF8. The Kindle e-reader, as one might expect, uses the latter format. Despite this, we need not concern ourselves greatly with MOBI/KF8, because Amazon provides a tool known as KindleGen that will convert an EPUB file to a MOBI/KF8 file. The output file, which has a file extension of .mobi, is Kindle-compatible. KindleGen can also accept files in HTML or XHTML, and Amazon recommends its use for publishers wishing to create Kindle books in-house.

Two quick and dirty practical exercises
As a preliminary exercise, I needed to familiarise myself with the basics of producing an eBook and getting it on to a Kindle. As a starting point, I downloaded the Amazon Kindle Publishing Guidelines, which are available as a .pdf file. Google ‘Amazon Kindle Publishing Guidelines’ to obtain the latest version of this document. I then downloaded and installed the KindleGen tool provided by Amazon (the procedure is explained in the publishing guidelines) and I also downloaded and installed Notepad++, a freeware file-editing tool with some very powerful features including the ability to run Regular Expression (RegExp) scripts. Throughout the conversion exercise I was using MS Word on a PC running under Windows 7.

The following is a quick and dirty practical exercise to put a mini-eBook onto a Kindle e-reader. Note that from now on I will use the term ‘Kindle e-reader’ to mean any device capable of reading a Kindle eBook. These include not just dedicated devices such as the Kindle Paperwhite and the Kindle Fire (the latter basically a customised Android tablet) but also iPhones, iPads, Android devices or laptops running the appropriate Kindle app or software.

For this exercise, you will require such an e-reader, together with an Amazon account. Your Kindle e-reader will have an email address in the format {my Kindle email address} This will be the address you set up when you registered the device and you can remind yourself by going to the Amazon website and selecting Your Account -> Manage Your Kindle -> Manage Your Devices.
To convert a document and load it onto your kindle, you will need to use a slightly different email address: {my Kindle email address} Simply email any small document (MS Word, .rtf or .html) to this address, putting ‘Convert’ in the subject. Conversion usually takes no more than a few minutes. You then will receive an email advising you that the conversion has been completed.
Go to Your Account -> Manage Your Kindle. In ‘Your Kindle Library’ you will see your newly-converted document at the top of a list of your Kindle documents. Assuming your Kindle e-reader is connected to the internet, your document should appear as downloadable to it (exactly how it is displayed depends on your device as the implementation varies from platform to platform). I found this exercise to be a useful introduction, but as I shall explain shortly, it is not suitable for producing a full-sized eBook. There is really only one way to accomplish this, and it is to use the KindleGen tool provided by Amazon. Here is a second quick and dirty practical exercise, this time using KindleGen for converting an HTML file.
Set up a directory on your PC and create a command line .bat file with the following command:

c:/kindlegen/kindlegen.exe {myfile}.htm>errors.txt

Running the command line file will generate the files {myfile}.mobi and errors.txt. The latter will contain one or two warning messages, because we are not at this stage converting a genuine eBook. However, the {myfile}.mobi can be read on a Kindle or Kindle-enabled device. Send the file to the {my Kindle email address} email address, and download it to your device as before. This might seem very simple, but now try exporting your lengthy manuscript from your word processor to HTML, converting it with KindleGen and trying to read the resulting .mobi file on your device. If your Word document contained a Table of Contents, this will appear as a series of hypertext links to the chapters of your book. The links will work – but they will be very slow. If you have kept each chapter of your book as a separate document (as I did) and haven’t at any stage combined them into a single massive manuscript (as I did periodically for test purposes and to circulate to interested parties) then there is no need to try this: just take my work for it).

Here’s why – eBook files are basically HTML files contained in a wrapper. Your eBook may be thought of as a website, and hypertext links work exactly the same way as they do on a website. Now imagine a website that held all its content on a single, massive page. Any hypertext linking within it would run pretty slowly. Of course, websites consist of many pages, with hypertext links typically taking you from one page to another. That is exactly how your eBook needs to be structured if your readers are to enjoy what Amazon term a ‘good reading experience’.

Preparing your manuscript for conversion to an eBook
As noted above, I kept each chapter of Humans: from the beginning as a separate MS Word document. The ‘manuscript’ to be converted into an eBook comprised MS Word documents for the 32 chapters, an introduction and a glossary, together with a title page, copyright notice, acknowledgements and attributions. The chapters and introduction (though not the glossary) were referenced using the MS Word citations tool. In addition there were maps, infographics and plates and illustrations. These I decided to keep separate from the main text on the grounds that a reader would find it easier to access them from a central index than would be the case if they were embedded in individual chapters. My task was to transform this into an EPUB document that could in turn be converted to the Kindle-compatible KF8 format with Amazon’s KindleGen tool.

The first step was to convert each Word document into an HTML file. MS Word provides a ‘filtered HTML’ export option from .doc and .docx files, but unfortunately this still produces a considerable amount of junk. Indeed, many books recommend simply copying the contents of each Word document into a flat text file. I feel that this is throwing out the baby with the bathwater, as you will lose all of your formatting in the process.

I created a series of styles to cover all aspects of formatting in each chapter – one each for chapter heading, section headings within each chapter, and body styles. I used the styles to handle indentation and before and/or after line spacing. I entirely eliminated the use of tabs, spaces and carriage returns to accomplish this. The result is that when exported to HTML, the body text of each document will comprise a series of series of paragraphs that lend themselves to formatting with cascading style sheets. In an eBook, as in a website, formatting is carried out using classes contained in a .css file.
The next issue I faced was references, of which my book contained large quantities. In an eBook, the reader should be able to look up a reference by simply clicking a hypertext link. They can then return by either 1) clicking a link on the reference that takes them back, or 2) using the ‘back’ function on their e-reader. The first method requires additional HTML coding and has the problem that it will always return the reader to the same point regardless of how many times the particular reference is cited in the text. As I was constantly citing multiple instances of references, I decided that the first method, though easier to implement, was actually the most suitable in my case.

While I was working on my book, I used Harvard-Anglia referencing (author(s), year; e.g. Smith, 2012) to save having to constantly look up what was being cited. However, the presence of large numbers of references cited in this style can interfere with the reading experience, so for the purposes of publication I switched to Nature referencing (as used in the science journal Nature), where the reference is assigned a number that refers to its entry in the bibliography. The references in my book are broken down by chapter, meaning that each chapter has its own bibliography. The methods I will describe apply to the referencing system I have just described, but they could be adapted for other systems if desired.

I first applied a style to the references. This served two purposes: firstly, the formatting could be again controlled through the cascading style sheets, and secondly it facilitated the attachment of hypertext links. To accomplish this, I created the following Word macro:

Sub ApplyCitationStyle()
Dim stylename As String
Dim exists As Boolean
Dim s As Style
Dim fld As Field

stylename = “In-Text Citation”
‘Check if the style already exists.
exists = False

For Each s In ActiveDocument.Styles
If s.NameLocal = stylename Then
exists = True
Exit For
End If

‘If the style did not exist yet, create it.
If exists = False Then
Set s = ActiveDocument.Styles.Add(stylename, wdStyleTypeCharacter)
s.BaseStyle = ActiveDocument.Styles(wdStyleDefaultParagraphFont).BaseStyle
s.Font.Superscript = True
End If
‘Now that the style really exists, select it.
Set s = ActiveDocument.Styles(stylename)
‘Apply the style to all in-text citations.
For Each fld In ActiveDocument.Fields
If fld.Type = wdFieldCitation Then
Selection.Style = s
End If

End Sub

The macro formats the references with a style called “In-Text Citation”, which results in them being displayed as superscripts. It isn’t actually necessary for it to do so, as you will have to implement superscripting with your cascading style sheets. The important point is that the references are now spanned by the style.

For each chapter document, I saved a copy and switched from Harvard-Anglia to Nature referencing before running the ApplyCitationStyle macro; I then inserted the bibliography at the bottom of the document using the Word ‘Insert Bibliography’ feature. For Nature referencing, this appears as a table, but I converted it to straight text and formatted it using a Word style. At the end of these steps, I had a series of ‘well behaved’ MS Word documents, one per chapter plus one for the introduction. These were ready for export into a series of HTML files, two per document, one to hold the text and the other the bibliography of that document.

From Word to HTML
Before beginning the conversion process, I set up a directory structure to hold my files. This would eventually form the backbone of my eBook:

1. Within a directory called ‘Build’, I created two subdirectories; ‘META-INF’ and ‘OEBPS’ (the subdirectory names are required by the EPUB standard; the name ‘Build’ was my choice);
2. Within ‘OEBPS’, I created three subdirectories; ‘content’, ‘css’ and ‘images’;
‘css’ held the .css file (as one might expect);
3. ‘images’ was used to hold the image JPEG or GIF files associated with my work; I created subdirectories within it for each category of image: these were ‘maps’, ‘infographics’ and ‘pictures’, together with a subdirectory named ‘cover’ to hold the book cover JPEG file;
4. Within ‘content’, I created the subdirectories ‘text’, ‘references’ and ‘toc’, together with one directory for each category of images (i.e. ‘maps’, ‘infographics’ and ‘pictures’);
5. The ‘text’ subdirectory held the files making up the main body of the text, i.e. chapters, introduction, glossary, title page, copyright notice, acknowledgements and attributions;
6. The ‘references’ subdirectory held my bibliography files;  
7. The ‘toc’ subdirectory held table of contents files, as will be discussed later;
8. The three image subdirectories held the container files which display the image files (maps, infographics, and plates and illustrations) and accompanying explanatory texts;

I was now ready to begin the export process and produce two HTML files for each document: one for the document text and one for the bibliography. For chapters, I used the naming convention ChxxN.htm and ChxxR.htm, where xx is the chapter number with leading zero and the suffixes ‘N’ and ‘R’ identify the chapter text and bibliography files respectively (‘N’ simply referred to the Nature referencing convention). Other main body text files I simply called by name, i.e. Introduction.htm, Glossary.htm, etc. The only bibliography file not following the ChxxR.htm convention was that pertaining to the Introduction; I called it IntR.htm. These conventions were purely of my own choosing, but the code described below is based on them. Using other naming conventions would require the code to be modified accordingly.

I exported each of Word files to HTML by saving as ‘Web page, filtered’ and opening the resulting file in Notepad++. Each still contained a significant amount of junk, and I also needed to wrap double-quotes (“) around the CSS class names, which was readily accomplished by Search and Replace. Note that the .CSS classes don’t necessarily have to have the same names as the corresponding Word styles and it was possible to rename them at the same time as I added the double-quotes. For example, I renamed In-Text Citation to Citation.

Next, I copied and pasted the formatted paragraphs and the bibliography from each HTML extract file to publishable HTML files set up using the following general template, taking care to ensure that encoding was set to UTF-8 for all files. Note that KindleGen will fail if this is not done.
Each document text file has the following format:

{my text heading}

[Body text copied from the export file goes here]

1. {my CSS file name} is the name of the css file (HFTB.css in my case)
2. {my div id} is a unique capitalised identifier, based on the name of the file, e.g. CH05, INTRODUCTION, GLOSSARY;
3. {my text heading} is the chapter name or name of the text as will appear in the eBook (e.g. 22: Of rice and men);
4. TOC.htm is a table of contents file for the main text, to be discussed below; the code provides a return hyperlink;

Each bibliography file has the following format:

{ my chapter name }

[Bibliography copied from the export file goes here]

1. {my CSS file name} is the name of the .css file (HFTB.css in my case)
{my chapter name} is the title of the chapter;
2. CH{ chapter number} is a four-character text string corresponding to the chapter number with leading zero, e.g. ‘CH05REF’ (the reference section for the introduction is ‘INTREF’);
3. RefTOC.htm is a table of contents for the bibliography, to be discussed below; the code provides a return hyperlink;

At this stage, I had two HTML files, ChxxN.htm (chapter text) and ChxxR.htm (bibliography) for each chapter (xx = chapter number with leading zero). Unfortunately, as noted above, the files still contained random junk, which I had to identify and remove by manual editing.

Commonly-occurring junk includes:
1. Unwanted spaces and other blank characters preceding and within HTML tags, and following after HTML close tags;
2. Unwanted tags, leading to non-well-formed HTML;
3. Unwanted Style attributes.

I now needed to establish hyperlinks from the citations in chapter text files to the corresponding references in the bibliography files. To this end, I used Regular Expression (RegExp) search and replace terms in Notepad++.

For each set of chapter text and bibliography files, I proceeded as follows:
1.      Open the bibliography file in Notepad++;
2.      Go to Search/Replace and select Regular Expression mode;
9.      Enter the replace string Citation”>$1
where xx = chapter number, with leading zero (e.g. CH05);
10.  Click Replace All;
11.  Enter the search string Citation”>(\d+),;
12.  Enter the replace string Citation”>$1, where xx = chapter number, with leading zero (e.g. CH05);
13.  Click Replace All;
14.  Enter the search string (\d+)
15.  Enter the replace string $1
,$2 where xx = chapter number, with leading zero (e.g. CH05);
16.  Click Replace All repeatedly until you receive the message “Replace: All 0 occurrence was replaced” [sic];
17.  Save the file;
With the above set of processes completed for each of my MS Word chapter files, I had completed the process of exporting main manuscript to HTML.

Logical and Physical TOCs
A Kindle eBook has two tables of contents (TOC): a logical TOC and a physical (or HTML) TOC. The logical TOC allows readers to navigate between chapters when using a Kindle e-reader. The exact implementation depends on the device used, but in general the reader will be presented with a list of the book’s contents and will be able to navigate to the chapter of their choice. The physical TOC, on the other hand, will be encountered when the reader pages through the book from the beginning. Just where it occurs is up to the publisher, but I located it after ‘Acknowledgements’ and before ‘Introduction’ near the start of the book. It serves the same purpose as the logical TOC, allowing the reader to navigate to the chapter of their choice. Unlike the logical TOC, it cannot be summoned on demand, other than via the logical TOC itself.

In the EPUB 3.0 standard, the logical and physical TOCS can be accommodated in the same HTML file. Previous implementations required the logical TOC to be placed in a separate .nav file, in which the order of appearance for each item has to be coded explicitly. This means a simple re-ordering of the content requires recoding every single entry, which is tedious to say the least. For this reason, I adopted the EPUB 3.0 standard although EPUB 2.0 was suitable in every other respect.

In my implementation, both TOCs were accommodated in a file named TOC.htm, which resides in the content/toc subdirectory. In principle, both TOCs should also be able to share the same code but in practice this was found to cause problems with some implementations.

The TOC.htm file has the following format:
xmlns:epub=“” xml:lang=“en”>


[Physical TOC goes here]

[Logical TOC goes here]

The physical TOC consisted of a series of entries, one for each item directly referenced from it:

1. {my CSS class} is a CSS class to format the line;
2. {file name} is the target file name including extension, e.g. Ch05N.htm;
3. {file div id} is the div id (see above) of the target file, e.g. CH05;
4. {text description} is the text appearing within the

tags of the target file (see above), e.g. “27: An enigmatic civilisation”;

The logical TOC comprises an ordered list enclosed within a

[Logical TOC entries go here]

The logical TOC entries take the form:

In theory there is no reason why the ordered list could not serve as the physical as well as logical TOC. It should be possible to suppress the (unwanted) automatic numbering that appears on an ordered list; however on some Kindle e-reader implementations this does not work, and the automatic numbering still appears.

Other TOCs
The logical and physical TOCs described above are mandated (or at least highly recommended by Amazon) and for my eBook, provide navigational access to all the items in the content/text directory. The EPUB standard provides for the nesting of TOCs so that, for example, an entry marked ‘References’ could be expanded into the bibliography list by chapter. Unfortunately, the Kindle platform does not support nesting for the logical TOC, but there is no restriction on using physical TOCs. 

Accordingly, I provided four additional TOCs: one for accessing the bibliography (RefTOC.htm), one for accessing the maps (MapTOC.htm), one for accessing the infographics (FigTOC.htm), and one for accessing the plates and illustrations (PicTOC.htm). All were in turn accessible from the main TOC.

The RefTOC.htm file has the following format:

[Bibliography entries go here]

The bibliography entries have the following format:

1. {my CSS class} is a CSS class to format the line;
2. {chapter no.} is the chapter number with leading zero (for the introduction the target bibliography file is IntR.htm);
3. {chapter title} is the text appearing within the

tags of the target bibliography file, e.g. “27: An enigmatic civilisation”;

The MapTOC.htm, FigTOC.htm and PicTOC.htm files follow the same general format as RefTOC.htm and hyperlink to the container files which display the book’s visual matter. As with the bibliography files, the container files contain return hyperlinks to their respective TOCs.

The Glossary
I provided a glossary in which commonly-encountered terms were defined and explained. Entries could be accessed alphabetically from within the glossary via a hyperlinked alphabet, or via hyperlinks in the main body of the book’s text. Unfortunately, there was no quick and easy way of doing this and it was necessary to insert the relevant links on an individual basis. Again, as most glossary items were multiply accessed, no return link was provided and the reader returns by use of the ‘back’ function on their Kindle e-reader.

The content.opf file
The content.opf file sits in the OEBPS directory and is central file of an EPUB package. It defines the structure of the eBook and holds its metadata. Very briefly, it contains four sections: the section, section, section and section. The section provides metadata, which is essentially data about data rather than content. In this implementation, metadata is supplied for the ISBN number, book title, author name, publisher name, date of publication, book description, and subject. The section provides a list of paths, identifiers and properties for each file in the package; and the section lists in order of appearance the identifiers for each file in the package, thus defining the order in which they would appear were the reader to page through the entire book.

The  content.opf file has the following format:

urn:isbn:{my ISBN no.}
{my book title}
{author name}
{my publisher}
{a brief description of the book}
{my subject 1}
{my subject 2}
{my subject 3}


[One entry for each of the content files from the content/text/ subdirectory]

[One entry for each of the container files from the content/maps/ subdirectory]

[One entry for each of the map image files (in all cases, {type} = JPEG)]

[One entry for each of the container files from the content/infographics/ subdirectory]

[One entry for each of the infographic image files (in all cases, {type} = GIF)]


[One entry for each of the container files from the content/pictures/ subdirectory]
[One entry for each of the picture image files (in all cases, {type} = JPEG)]


[One entry for each of the bibliography files from the content/references/ subdirectory]

[One entry for each of the HTML and image files in the package; {id ref} will be either the div id for the HTML files or the unique id based on image name for the image files]

Building the package
At this point, the package was almost complete. It remained only to add the container.xml file to the META-INF directory and the mimetype file to the Build directory.
The container.xml file simply tells an eReading device where to find the content.opf file, and it has the following format:

The mimetype file defines the file as an EPUB and ZIP file. It is a text file with no file extension containing a single line of text:
The next step was to zip the whole package up into an EPUB file and then convert this to a Kindle-compatible MOBI/KF8. In the Build directory, I set up two .bat files; compress.bat and mobimake.bat. I also installed the Zip.exe utility in the Build directory.

Format of compress.bat:
zip {my book}.epub -DX0 mimetype
zip {my book}.epub -rDX9 META-INF OEBPS
Format of mobimake.bat:
{my KindleGen path}/kindlegen.exe {my book}.epub>errors.txt

Having set up these files, I ran compress.bat to produce an EPUB file, which in my case was called hftb.epub. Before converting this to the MOBI/KF8 format, it was necessary to check it for errors. There are many free websites that will upload and validate an EPUB file; I used this one: (note that it does not have a www. prefix). Once I had ironed out the inevitable errors, it was time to take the final step and run mobimake.bat. This created the MOBI/KF8 file, which in my case was called It also outputs the file errors.txt, which lists errors, warnings and approximate deliverable file size. This latter figure forms the basis of the ‘delivery fee’ that is charged by Amazon to the author against the royalty payment for each sale.

Testing and release
With the book now built, the final stage was testing. This entailed individually testing every single hyperlink in the book and also checking for formatting errors. This was a laborious procedure for a long book, but I viewed it as essential. A small number of issues were identified, which were easy to fix but would have made the book seem less polished as a product had they been allowed to remain. Testing was carried out on four platforms: a dedicated Kindle device, an iPhone, a Nexus 7 Android tablet and a PC. Full testing was carried out only on the latter.

On 4 March 2014, I uploaded Humans: from the beginning to the Amazon Kindle bookshelf, and it has been in sale ever since. In the weeks that followed, a few errata came emerged, highlighting another advantage of the eBook over its printed counterpart. It was simply necessary to make corrections and upload the corrected version. Previous purchasers receive this free of charge, similar to the way that apps on a smartphone are periodically updated. I added a ‘release note’ with the updated version as a new page located after the bibliography.