God spaketh, but why? Part 7: Voice

After a mid-winter break to look at some of the ways we can generate different ‘truths’, let’s return to the issue of why humans, as a species, no longer live in harmony with nature. Some humans live in perfect balance with their environment but, usually, when ‘we’ ‘discover’ such people, we try to change how they live. As I said in a post entitled ‘What Makes a Fair Society?’, I do not believe that our current  ‘fast-track to oblivion’ approach to life is ‘just human nature’ for it is not a trait of all human beings. It’s a cultural defect, in my opinion, but how far back does it go?

We’ve seen that our earliest ancestors lived through many periods of natural turmoil but, somehow, they survived. I have no doubt that the ability to understand and use, if not make, fire was key to the survival of early humans. We most likely developed the ability to learn from past events through storytelling before realising that we could invent a story too, a story of a different future where nature was controlled.

Look who’s talking
In the last post of this series, we saw that there is no consensus on the origin or age of human language —our voice-based mode of communication. Last August, New Scientist ran a story on the evolution of the human voice. “Anatomy doesn’t impede primates from producing distinct vocalisations that are homologues to different human vowels”, says Adriano Lameira of the University of St Andrews, who had previously shown that orang-utans can mimic some of the sounds of human speech.

It makes sense to me that speech gradually improved over the course of human evolution but scientific evidence is a bit more reliable than intuition. There is evidence that Neanderthals and Denisovans could speak, at least to some extent. “Neanderthals most likely had brains capable of learning and executing the complex manoeuvres involved in talking, but their speech would not have been as clear and comprehensible as ours, perhaps accounting in part for their extinction,” says Philip Lieberman of Brown University in Rhode Island. “I think Neanderthals could talk, but more indistinctly than us.”

Neanderthals lived from 350 to 40 thousand years ago and, based on limited archaeological evidence, Denisovans were known to be alive 40 thousand years ago but if the temporal range is known, it’s probably behind a paywall. It is in this context that the ‘cognitive revolution’ of 70,000 years ago, as argued by Yuval Noah Harari, should be considered. Humans other than Homo sapiens could talk but, for various reasons, H. sapiens did it best.

Back to the New Scientist article. Researchers at the Hebrew University of Jerusalem examined DNA from two modern-day people, four humans who lived within the last 50,000 years, two Neanderthals, a Denisovan and six chimpanzees. The analysis reveals key evolutionary changes that reshaped our faces and larynxes; not major mutations in our genes but tweaks in the activity of existing genes that we shared with our immediate ancestors. The theory goes that changes in gene activity seem to have given us flat faces, and led to the resculpting of the larynx, moving it further down in the throat, allowing our ancestors to make sounds with greater subtleties. Which I assume equates to having a wider vocabulary.

All speech-ready?
While some researchers focus on similarities between different species of human, William Tecumseh Sherman Fitch III, an evolutionary biologist and cognitive scientist at the University of Vienna, says “…anatomically speaking, macaques are perfectly well equipped for humanlike speech…. And because their vocal anatomy is nearly identical to that of other monkeys and apes—and to most other mammals—these animals are also ‘speech-ready’. Anthropologists who scour the fossil record for evidence of when our ancestors learned to speak are “wasting their time” he says, because all human ancestors had vocal anatomies capable of speech. Instead, the field should focus on genetic factors known to be necessary for proper speech and language development, to figure out when humans gained ‘the gift of the gab’. Monkeys and apes lack the neural control over their vocal tract muscles to properly configure them for speech, but “If a human brain were in control, they could talk,” Fitch concludes.

So, this isn’t a debate about to be wrapped up soon, but that’s fine as I don’t think our ability to talk is important to why we live apart from nature. However, it does give us a huge advantage when creating a story for others to follow, to believe in.

Mandy Meikle edits the Reforesting Scotland Journal. Some might say she thinks too much but that’s not possible; it’s what one thinks about that matters!

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Measuring what, exactly?

In the previous post, we looked at mistakes made by assumption; we hear a ‘fact’ so frequently, or from such trusted sources, that we do not think to question its validity. These mistakes may be innocent, a result of sloppy thinking or having too little time to be thorough. But miscommunication can also be deliberate, devious, and I was going to look at some examples of devious miscommunications. However, now I’ve thought about it a bit, I find it nigh on impossible to tell the difference, at least without a decent amount of background knowledge. People really do believe the most unbelievable things but that is not necessarily the same as ‘lying’. We all see different aspects of any story depending on our past experiences and our current beliefs.

A news editor, for example, wants a headline to attract readers and sell papers; the quality of the calculations therein are way down the list of what makes a good news story. A recent episode of More or Less on BBC World Service queried a headline claiming that 15 of the largest ships emit as much pollution as all the cars in the world. This again? Long-distance travel by ship is absolutely key to our globalised world and, in 2016, the global cruise industry generated a revenue of approximately 35.5 billion U.S. dollars. The question of whether shipping is any better environmentally than other forms of long-distance transport is not new. But really? As much ‘pollution’?

The 15 ships figure was traced back to a Guardian article from 2009. The pollution referred to is sulphur, which cars don’t emit to any great extent because their fuels are highly refined. On the other hand, ship (or bunker) fuel is very high in sulphur and other pollutants as it is basically the residue left over from the refining process. It’s the cheapest and dirtiest fuel, and its use on land is regulated against. But if the headline had read “15 of the largest ships emit as much sulphur as all the cars in the world but cars don’t produce that much”, not only would our editor have had cause to fear for his job, the debate to clean up shipping would have lost an eye-catching headline.

More or Less delves deeper. Dr James Corbett of the University of Delaware is an expert on shipping emissions and explains, “I helped prepare that calculation using some assumptions, and a thought experiment, because at that time the shipping industry was just beginning to build these largest ever container ships”. So, in addition to the figure failing to compare like with like, the claim wasn’t even about what was happening now, but about what might in theory happen under certain circumstances. But various media outlets took this figure and ran with it. Is it a ‘lie’ to quote it back to someone?

For me, More or Less saved the best bit until last (7:00 min), when we learn that emissions from shipping in 2012 more than halved compared to 2008. As part of a cost-cutting exercise, certain ships halved their speed in order to use less fuel, and the impact on sulphur emissions was notable. This environmental bonus was a by-product of the recession, which made cost-cutting a necessity, not a switch to cleaner fuel in response to air pollution concerns. While I would feel some spark of optimism if shipping companies had heeded the environmental message, does it really matter why people change their behaviour so long as they do? By 2020, all marine fuel must have a sulphur content no higher than 0.5% (down from 3.5% today) so sulphur emissions from shipping should continue to fall.

Their incomprehensible vastness, coupled with our inexplicable belief that throwing stuff ‘away’ is dealing with our waste, means our oceans still suffer from some of the worst forms of pollution, due in part to the complexity of international laws but also the impossibility of enforcement. As long as we live in a society dominated by money, cost will lead to change that all the information in the world won’t bring. Until we change the story, of course.

Mandy Meikle edits the Reforesting Scotland Journal, amongst other things, and has her fingers crossed for 2018!

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The values of the teacher

In the last post, I reported on a three-day symposium where US state and federal judges were taught about science and scientific scepticism by a man with rather questionable values. The teaching is an excellent idea as even with a scientific background, it is easy to make assumptions about the accuracy of seemingly reliable ‘facts’. But the values of the teacher will influence the lesson. Any teacher will have a basic understanding of a topic, which may develop over time through further study and experience. So long as they are not just ‘cherry-picking’ data to support their ideas whilst dismissing anything which might counter them, the teacher should question long-held beliefs as new information emerges. But some people just cannot accept that their beliefs might be wrong; such people do not make good teachers.

One of the big problems in communicating science is how to simplify a complex message without rendering it inaccurate, if not plain wrong. To do so well takes time, another resource we seem to be running short of. The clear, cool waters of understanding may also be muddied when a guestimate becomes a widely-accepted ‘fact’. My particular favourite is the ratio of human to non-human cells in our bodies.

Question the questions
It used to be believed that only 1 in 10 of the cells of our bodies was of human origin, the rest being microbial. This figure came from an estimate made in 1972 by microbiologist Thomas Luckey; it was never meant or expected to be widely quoted decades later. Turns out that Luckey had roughly estimated the figure by scaling up the number of bacteria in a gram of faeces, to the whole length of the alimentary canal (mouth to anus) when most bacteria reside only in the colon. So while technologies such as DNA analysis might shed new light on a problem, simply taking the time to go back to original data can prove just as revelatory. Today, perceived wisdom dictates a roughly 1:1 ratio for microbial to human cells (with slightly more microbes but not ten times more).

This new information was published in Nature in January 2016 and the article included a graphic depicting the relative proportions of different cell types based on number and mass. I feel I should have known this already, but I was surprised to learn that over 80 per cent of the human cells that make up our bodies are red blood cells, also known as erythrocytes. These small cells contain no nucleus or organelles; they are simply packed with haemoglobin, the molecule which transports oxygen and carbon dioxide to and from our tissues. As far as genes and replication go, some cell biologists might say that red blood cells are not true cells at all.

Which got me thinking: why would anyone care about the ratio of human to non-human cells within our bodies if not for matters pertaining to ‘self’? And surely genetic material is key here? If we consider how many DNA-filled human cells, carrying our genes, are replicating in our bodies compared to how many DNA-filled non-human cells are replicating in our bodies, it comes out as just under 7 per cent human, even lower than Luckey’s 10 per cent estimate. It is not just the answers to questions which should be queried, but sometimes the questions themselves.

Correlation is not causation
Another potential trap on the road to truth is confusing correlation with causation and a good example of this featured in BBC Radio 4’s Inside Science earlier this year (21:18 min). In evolutionary theory, genes mutate over time and give new functions to their owners. If these new functions are beneficial, the mutated gene will likely be passed on to future generations. Fruit flies feed on rotting fruit and, until recently, it was understood that their ability to tolerate a high-alcohol environment was due to the presence of an enzyme which breaks down ethanol. Today, genetic engineering allows us to reconstruct ancient gene varieties and test them in live animals. Despite the modern fruit fly having this mutated alcohol metabolism gene, there was no difference between the ethanol tolerance of the modern fruit fly and one carrying the ancient, non-mutated version of the gene. So while a plausible link had been made, in this case the gene mutation was not responsible for the ethanol tolerance of fruit flies.

Furthermore, the gene mutation idea was not a strong claim made in the paper where it first appeared. Nonetheless, this nugget of information made it from the world of peer-reviewed and seldom-read papers into the academic textbooks, where students the world over would innocently assume its truthfulness. There was no intention to mislead in either of these cases, just mistake by assumption.

In the next post, I’ll look at some examples of devious miscommunications. In the mean time, question everything, have a happy Hogmanay and all the best for 2018!

Mandy Meikle edits the Reforesting Scotland Journal, and is helping to bring the Cup Conscious Café movement to Scotland.

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So, what is true?

I thought I’d have a break from considering how Homo sapiens came to dominate nature, partly because I know I’m going to enter territory which will upset some religious people and that’s not very Christmassy. Following on from the last post looking at language, if you have access to this year’s BBC Christmas Lectures, you might enjoy Professor Sophie Scott’s exploration of the unstoppable urge for human and animal life to communicate.

My academic background was in microbiology, although I veered from that path longer ago than I care to remember! Science is a process of discovery, it is dynamic, and I believe that “science is the best defence against believing what we want to”, as Professor Ian Stewart put it. So I was concerned to learn that US judges were being schooled in scientific scepticism by an industry risk analyst with a penchant for coming down on the side of the polluter.

According to a Guardian article in early October 2017 by Jie Jenny Zou and Chris Young of the Center for Public Integrity, “22 state and federal judges … got a crash course in scientific literacy and economics. The three-day symposium was billed as a way to help the judges better scrutinize evidence used to defend government regulations” but also served another purpose: “it was the first of several seminars designed to promote ‘skepticism’ of scientific evidence among likely candidates for the 140-plus federal judgeships Donald Trump will fill over the next four years”.

The science instructor (singular!) was a risk analyst called Louis Anthony Cox Jr, who has deep industry ties and was recently appointed as chair of the US Environmental Protection Agency’s clean air scientific advisory committee. That’s the same EPA which has been haemorrhaging employees with a conscience since Trump took office. The Guardian article says, “Since 1988, Cox has consulted for the American Petroleum Institute [API], a lobby group that spent millions to dispute the cancer-causing properties of benzene, an ingredient in gasoline, and is now working to question the science on smog-causing ozone. He’s also testified on behalf of the chemical industry and done research for the tobacco giant Philip Morris…. For a $4,000 honorarium, Cox delivered two closed-door lectures at George Mason [George Mason University’s Law & Economics Center in Arlington, Virginia]: ‘a primer on the scientific method’ followed by a session aimed at ‘understanding what science can and cannot do’.” Nice work if you can get it. Included in Cox’ presentation “were slides urging judges to be wary of EPA science on fine particles – a pollutant he has been researching for API”.

The article goes on to say that “the Center claims to have trained more than 5,000 state and federal judges, including three sitting supreme court justices. Almost 1,000 state attorneys general and their staff attorneys have attended its programs…. With a new era of environmental deregulation under way, issues ranging from the Obama administration’s clean power plan to offshore drilling in the Arctic are landing in the courts for final say. The stakes are enormous for the industry, which is simultaneously confronting a wave of lawsuits that seek billions of dollars in damages for climate-change impacts. Among the defendants are API members such as ExxonMobil.”

My concern is not that law-makers are being briefed on scientific method, it’s that the teacher seems to have some obvious biases. But then so do I. I would have been delighted if those same law-makers were being schooled by David Attenborough or someone else who understands the need to change how we live – to change the story of perpetual growth on a finite planet, to understand that we pull on the threads of the web of life at our peril. The values of the teacher will alter the lesson and I’ll consider this in the next post. In the meantime, enjoy the festivities and I hope Santa brings you a Keep Cup (other reusable cups are available!)

Mandy Meikle edits the Reforesting Scotland Journal, and is helping to bring the Cup Conscious Café movement to Scotland.

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God spaketh, but why? Part 6: Language

This series attempts to gather thoughts around the change in human behaviour which led us to dominate nature rather than live in balance with it. I have referred to Sapiens: a brief history of humankind written by Israeli historian, Yuval Noah Harari. Harari argues that our ability to cooperate flexibly in large numbers required a brain that could create and believe in fiction, a skill thought to have appeared some 70,000 years ago. If this figure is accurate, this ‘cognitive revolution’ took place thousands of years after several species of human being survived various periods of glaciation in places relatively unravaged by snow and ice, some of whom were able to use fire to keep cold and predators at bay, and to cook food. And I reckon they could talk.

I believe that to survive Ice Ages would have required cooperation, but then wolves cooperate, it’s not a uniquely human strategy. As I said in Part 1, we probably developed the ability to learn from past events, such as floods and famines, through storytelling, before we realised that we could invent a story too, a story of a different future. Perhaps the first was a story of cooperation, of working together  to prevent, or at least lessen, the impact of future extreme weather events on our numbers. Humans had a self-awareness which gave death a whole new meaning. It was about more than flight, fight or freeze reactions – at some point, we learned how to question the present and plan a more secure future.

It is obvious that some kind of language would be required to transmit any story but many species have sophisticated means of communication, whether or not we consider it a ‘language’ as such. For most species, the story being communicated is rigid, genetically programmed, perhaps. Ants don’t withhold their labour for better reward! We are beginning to understand (or remember) that most species communicate, often in ways we can’t detect with our own senses. David Attenborough’s excellent Blue Planet 2 introduced the world to singing fish, and Dame Judi Dench is soon to be on TV talking about the “secret lives of trees and the stories that they tell us”! Understanding our place in the world, that we are part of nature, was lost when we decided to control nature for our own benefit. Maybe one cannot control another species unless convinced it is subordinate, certainly not an equal. Having god put it there for you is certainly a good story, but why do we no longer thank those who sustain us. I’ll consider indigenous cultures and values in a future post.

But back to language, which is as important for teaching harmonious living as it is for something less sustainable. According to the Darwin Correspondence Project at Cambridge University, “Darwin started thinking about the origin of language in the late 1830s…. In his private notebooks, he reflected on the communicative powers of animals, their ability to learn new sounds and even to associate them with words. ‘The distinction of language in man is very great from all animals’, he wrote, ‘but do not overrate—animals communicate to each other’. There seems to be a spectrum of belief running from language being unique to Homo sapiens, God-given in some cases, to it being “derived from natural, instinctive utterances that were shared with some animals… and spread gradually according to various natural laws and processes”.

Darwin eventually published his views on language in Descent of Man (1871), acknowledging that language had “justly been considered as one of the chief distinctions between man and the lower animals”; but he went on to emphasize the similarities between animal and human communication. Debate continues today because language is ephemeral, detectable only by indirect proxies, such as the presence of a certain bone or the ability to make symbolic objects. A few years ago, analysis of a Neanderthal’s fossilised hyoid bone – a horseshoe-shaped structure in the neck crucial for speaking – suggested the species had the ability to speak. But whether it did or not is the tricky bit to prove. The report continues, “It was commonly believed that complex language did not evolve until about 100,000 years ago and that modern humans were the only ones capable of complex speech. But that changed with the discovery of a Neanderthal hyoid bone in 1989…”. Much older hyoid fossils, over 500,000 years old, have been discovered in Spain and are attributed to Homo heidelbergensis.

There is no consensus on the origin or age of human language. Once again, Wikipedia sheds some light on the complexity of what is meant by language. Utterances or descriptive statements? Does song count? How about imitation? While Neanderthals may have been anatomically capable of producing sounds similar to modern humans, the Neanderthal brain may have not reached the level of complexity required for modern speech. Whatever the truth is, I think it’s safe to say that, along with the use of fire, language was a skill many humans possessed long before Harari’s Cognitive Revolution. Perhaps it was around a camp fire that people first discussed how to make life better: free from hunger and cold, predation and death. A discussion that continues to this day.

Mandy Meikle edits the Reforesting Scotland Journal, amongst other things, and welcomes all comments and corrections. It also seems that links have returned so many thanks to bug-fixers!

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God spaketh, but why? Part 5: Fire

We started this series by looking at differing human values and asked why our relatively recent, and overwhelmingly dominant, cultural narrative no longer pays heed to the fact that the environment sustains each and every one of us: all species, plants, animals, everything. This fundamental change in how we live has taken place countless times as people have chosen, or been forced, to leave behind the old ways of hunting and gathering, migrating with the seasons as required, and settle.

There’s nothing wrong with change. Without change, life would never have gotten around to photosynthesising [1] and the Earth would be incapable of supporting complex life. But problems arise when the rate of change is too rapid for ecosystems to adjust to. I am sure settled agriculture, on a small scale with locally-available natural inputs, supplemented by a bit of hunting and foraging can be a very sustainable way to live. Certainly beats popping down to the supermarket for plastic-wrapped crap one can barely identify, let alone reproduce. But that’s for another post, as is population density!

We’ve seen previously [2] that Homo sapiens evolved some 300,000 years ago into a world which already contained several other species of human. Convention has it that humans began using fire on a regular basis around the same time, although new research pushes that date back by over a million years – another indication that humans had many skills we assume only H. sapiens possessed. For most creatures, fire is well up the list of things to fear, perhaps second only to being eaten. Understanding fire enabled warmth to be generated in cold conditions, food to be cooked and thereby impart better nutrition, and was quite good at scaring away predators – remember we’re back in the days when humans were not at the top of the food chain. And, in the fullness of time, fire would provide the ideal setting for storytelling.

An article from 26 January 2017 in Sapiens [3], a digital magazine about the human world not Yuval Noah Harari’s book mentioned in previous posts, explains that the use of fire by early humans was not marked by a single discovery but via several stages of development.  The authors “surmise that during the first stage, our ancestors were able to interact safely with fire; in other words, instead of simply running from it, they had become familiar with how it works. To get a deeper understanding of this stage, we can look to research done on chimpanzees…which found that chimps clearly understand the behavior of fire enough to have lost the fear of it that most animals typically possess”. Chimps have been observed “monitoring the progress of a passing wildfire from a few meters away and then moving in to forage in the burned-out area. So while chimps cannot build or contain fires, they understand how fire moves across the landscape, and they use this knowledge to their benefit. It is not hard to imagine a similar scenario playing out among small groups of our own early ancestors, perhaps the australopithecines, who lived from around 4 million years ago until about 2 million years ago in East Africa. The first stage may have persisted throughout much of prehistory”.

“The second stage would be when people could actually control fire – meaning they could capture it, contain it, and supply it with fuel to keep it going within their living areas – but they were still obtaining it from natural sources like forest fires… During the final stage, humans learned how to make fire, but again, we are not yet sure when this happened. Starting about 400,000 years ago, we begin finding much better evidence for human-controlled fire, such as intact campfires, or ‘hearths’ that contain concentrations of charcoal and ash inside caves, where natural fires don’t burn. Furthermore, the number of sites with such evidence increases dramatically. So it is clear that by this time, some hominins in some regions could manage fire and thereby control it, but whether they could make it remains an open question”. Given its importance, one can understand why many cultures have reference to tending an ‘eternal flame’, and why those who could make fire rather than merely tend an existing flame, could very well have been seen as god-like.

Writing in Scientific American on 19 June 2017 [4], Amber Dance explains how difficult it is to say when humans started to use fire regularly but believes “it almost certainly occurred by 300,000 years ago”, around the time that H. sapiens evolved in East Africa. Dance tells of new findings of 1-million-year-old fragments of burned bone as well as ash in South Africa’s Wonderwerk Cave, suggesting that 300,000 years ago is an under-estimate. Furthermore, the most distant estimates push that first-fire date back to 1.6 million years ago. These are times way before the emergence of H. sapiens.

In the last post [5], I suggested that H. sapiens may have had a creation story in place well before the Cognitive Revolution, thought to have taken place some 70,000 years ago, enabling modern humans to cooperate flexibly in large numbers through a shared story. “In the beginning, there was light”. Perhaps the light was firelight?

Mandy Meikle edits the Reforesting Scotland Journal [6], amongst other things, and is well aware that many people have dedicated their lives to studying history and anthropology, while she is merely dabbling. All comments and corrections gratefully received.

References
1. https://mandymeikle.wordpress.com/2015/05/24/when-worlds-collide/
2. https://mandymeikle.wordpress.com/2017/11/22/god-spaketh-but-why-part-3-tough-times/
3. https://www.sapiens.org/archaeology/neanderthal-fire/
4. https://www.scientificamerican.com/article/quest-for-clues-to-humanitys-first-fires/
5. https://mandymeikle.wordpress.com/2017/11/28/god-spaketh-but-why-part-4-all-humans/
6. http://www.reforestingscotland.org/publications/journal/

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God spaketh, but why? Part 4: All humans

I have set myself a challenge to post once a week for 5 months on where it all went wrong, on why humanity is decimating the environment and not even bothering to share the loot fairly. We all live by a story, a narrative, a paradigm. We all have our own rules of ‘right’ and ‘wrong’, our own societal norms and cultural values. Some, such as not killing other people, are fairly universal; others, such as what to wear, vary wildly. I’ve written before [1] about the lack of agreement between people you might think would get along, such as those fighting social and environmental injustice. I really do believe that most people intend to do good most of the time, it’s just that there are a wide range of opinions out there over what ‘good’ is and I’m interested in why that is.

In the last post [2], we saw that modern humans (Homo sapiens) lived through glaciations and volcanic winters, and speculated whether natural disasters might have selected for those with superior communication skills. One of the best books I’ve read in a long time on human evolution and development is Yuval Noah Harari’s Sapiens: a brief history of humankind [3]. Harari describes human evolution well, and I feel it’s worth reproducing his take on it to supplement previous posts. “We are used to thinking about ourselves as the only humans, because for the last 10,000 years, our species has indeed been the only human species around. Yet the real meaning of the word human is ‘an animal belonging to the genus Homo’, and there used to be many other species of this genus besides Homo sapiens.”

He continues, “Humans first evolved in East Africa about 2.5 million years ago from an earlier genus of apes called Australopithecus, which means ‘Southern Ape’. About 2 million years ago, some of these archaic men and women left their homeland to journey through and settle vast areas of North Africa, Europe and Asia…. The result was several distinct species… Humans in Europe and western Asia evolved into Homo neanderthalensis” aka Neanderthals, who “were adapted to the cold climate of Ice Age western Eurasia. The more eastern regions of Asia were populated by Homo erectus, who survived there for close to 2 million years…” while “On the island of Java, in Indonesia, lived Homo soloensis, who was suited to life in the tropics. On another Indonesian island – the small island of Flores – archaic humans underwent a process of dwarfing. Humans first reached Flores when the sea level was exceptionally low, and the island was easily accessible from the mainland. When the sea rose again, some people were trapped on the island, which was poor in resources…. Over the generations, the people of Flores became dwarves”. These small humans are nicknamed ‘hobbits’. More recent discoveries include Homo denisova, identified from a fossilised finger bone found in the Denisova Cave in Siberia in 2010.

Harari points out that “While these humans were evolving in Europe and Asia, evolution in East Africa did not stop. The cradle of humanity continued to nurture numerous new species, such as Homo rudolfensis, Homo ergaster, and eventually our own species…Homo sapiens… The members of some of these species were massive and others were dwarves. Some were fearsome hunters and others meek plant-gatherers. Some lived only on one island, while many roamed over continents. But all of them belonged to the genus Homo. They were all human beings.”

The study of human evolution is a rapidly changing field [4] but safe to say there were numerous migrations of Homo species over hundreds of thousands of years, and there were several species of human who survived in a hostile climate long before Harari’s Cognitive Revolution. We saw previously [2] that severe conditions reduced human beings to a dangerously small number. One example was the long glaciation between 195,000 to 123,000 years ago, where early humans survived in caves along the southern coast of Africa, at a place called Pinnacle Point. In December 2012, Professor Curtis W. Marean of Arizona State University wrote in Scientific American [5], “While elsewhere on the continent populations of H. sapiens died out as cold and drought claimed the animals and plants they hunted and gathered, the lucky denizens of Pinnacle Point were feasting on the seafood and carbohydrate-rich plants that proliferated there despite the hostile climate. As glacial stage 6 cycled through its relatively warmer and colder phases, the seas rose and fell, and the ancient coastline advanced and retreated. But so long as people tracked the shore, they had access to an enviable bounty. From a survival standpoint, what makes the southern edge of Africa attractive is its unique combination of plants and animals. There a thin strip of land containing the highest diversity of flora for its size in the world hugs the shoreline.” A veritable garden of Eden.

Professor Marean thinks finds including blades made of silcrete (a hard rock difficult to work without heating), decorative seashells, and marine foraging, signal that people had, for the first time, begun to embed in their worldview and rituals a clear commitment to the sea. If he’s right, H. sapiens may have had a creation story in place before their Cognitive Revolution, which we’ll look at again next time.

Mandy Meikle edits the Reforesting Scotland Journal [6], amongst other things, and would love to read more of Prof. Marean’s work but it seems to be behind a paywall.

Footnotes
1. https://mandymeikle.wordpress.com/2011/10/23/what-would-the-slogan-be/
2. https://mandymeikle.wordpress.com/2017/11/22/god-spaketh-but-why-part-3-tough-times/
3. http://www.ynharari.com/book/sapiens/
4. http://humanorigins.si.edu/evidence/human-evolution-timeline-interactive
5. https://www.scientificamerican.com/article/when-the-sea-saved-humanity-2012-12-07/
6. http://www.reforestingscotland.org/publications/journal/

 

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