Archive for the ‘Neanderthals’ Category
Homo naledi – an enigma shrouded in mystery
remains of at least 18 individuals found
Jacinta: So, having watched the much-discussed Netflix film, Cave of bones, describing and indeed taking us into the depths of the Rising Star underground cave system, frequented by the very enigmatic and so controversial Homo naledi species of hominin, and knowing that there is ‘blowback’ (presumably an Americanism) about the claims made re burial practices and lithic tool-making dating back a possible 300,000 years by this small-brained creature, remains of which have never been found above-ground, as far as I’m aware, we’ve decided to do one of our shallow dives into the claims and counter-claims…
Canto: So the researchers featured in the film include Lee Berger and John Hawkes, both names to reckon with in paleoanthropology, and they present a claim that they found evidence of burial practice in the Dinaledi Chamber at the barely accessible base of the complex Rising Star system. The film, I have to say, is edge-of-the-seat absorbing, though its intense focus on this one possible child-burial site, and the possible stone tool buried with the child, means you’d be forgiven for not having a clue about the broader perspective. That’s to say, that –
the Dinaledi Chamber of the Rising Star Cave has yielded 1550 identifiable fossil elements – representing the largest single collection of fossil hominin material found on the African continent to date.
Jacinta: Yes, that’s from University College London, but are they all from H naledi, I wonder? Apparently so, according to the Australian Museum:
The remains of at least 15 individuals were found in the Rising Star cave system in South Africa and announced as a new human species in 2015. The remains are the largest assemblage of a single hominin species yet discovered in Africa. Homo naledi combines primitive with modern features and is not a direct ancestor of modern humans.
They’ve been dated to between 335,000 and 236,000 years, but that presumably only indicates the dates in which the cave system was used. In another underground cave nearby (Lesedi cave), remains of at least two adults and a juvenile were found – also H naledi. Attempts to extract DNA have so far failed. And the fact that no fossils of these species have been found elsewhere isn’t perhaps surprising, caves being the place for such finds. But there’s hope for the future, according to the museum:
As only small parts of both caves were excavated, many more bones remain for future expeditions to recover.
Canto: So, in the film, Berger, Hawkes and their team reflect at large on ancient burial practices and religion and how far back they can be traced in hominin ancestry, but a very recent article in Nature throws something of a wet blanket over all this conjecture.
Jacinta: Yes, the film, which I have to say is very engaging, and even quite emotional for me, for some reason, came out at about the same time as peer reviews of an article by the researchers in an apparently controversial journal, eLife. These reviews were all pretty negative, as reported in Nature. Here’s one response:
“I want to understand how the H. naledi fossils got there. They are very important fossils, and critical to understanding human evolution,” says Jamie Hodgkins, a palaeoarchaeologist at the University of Colorado Denver, who was one of the study’s four reviewers for eLife. However, “there just wasn’t any science in the paper ultimately”.
And being still under the sway of the film, I feel a bit defensive for Berger and co. I know that Berger has a bit of a rep for being a rebel in the field, but I was interested in the possibilities raised by the film, which are somewhat similar to the conjectures being raised by Rebecca Wragg Sykes in her Neanderthal book, Kindred, especially in the chapter entitled ‘Many Ways to Die’, which explores possibilities re Neanderthal burial practices, as well as other ways of treating the dead, such as a kind of devotional cannibalism…
Canto: Mmmm, tasty.
Jacinta: Sykes cites many cases of Neanderthal cannibalism, and speculates as to the purpose. She considers that it was rarely out of hunger, and makes this interesting observation re our favourite rellies:
Bonobos once again provide an intriguing counterpoint. There are no recorded infanticides, yet several cases of mother-infant cannibalism exist, which also featured meat-sharing. In one situation, following a baby’s natural death the group spent an entire morning eating much of the body, before the mother carried away the remnants on her back.
Kindred, p 309
Canto Yes, well, I don’t think we’ve reached that stage of advancement.
Jacinta: Anyway, Sykes doesn’t go beyond speculation as to Neanderthal burial, but Berger et al really push their case hard, in their paper for eLife, titled ‘Evidence for deliberate burial of the dead by Homo naledi’. And via a very long and painstaking video analysis of the paper and its peer reviews by the intellectually and otherwise alluring ‘Gutsick Gibbon’ (aka Erica, I believe), which I’m only halfway through watching, I’ve become convinced that the evidence presented in the film isn’t convincing. As to the paper itself, I’m only getting snatches of it through the commentary. I was prepared to believe, before watching this video, that there was a bit of professional jealousy going on, due to Berger’s paleontological superstardom (given that the H naledi discovery, which Berger more or less owns, really is pretty mind-blowing), but the reviewers, being expert in such essential fields as archaeothanatology, sedimentology, micromorphology, palaeo-osteology and commonsensology, really focus on the failings, the lack of support for bold assertions, in very professional and indeed enlightening ways.
Canto: Yes, it actually made me want to read more papers on some of these subjects, and to be involved – to be young would be very heaven… The major theme of the response, to me, was ‘more research needed’, and especially from more specialised experts. And the film made me aware of how difficult – and dangerous – in situ research is for this site.
Jacinta: Yes it seems to be only the beginning with Homo naledi. But I think the criticism was more pointed, along the lines of ‘extraordinary claims require extraordinary evidence’. The signs of possible Neanderthal burials, which Sykes is quite carefully speculative about, at various sites (Sima de las Palomas, La Ferrassie, Shanidar), are all dated to less than 50,000 years ago, while the H naledi ‘burials’ – or is there only one? – are more than 5 times further back. Unlikely – though the brain size thing is a bit of a red herring to me. Think H floresiensis – too primitive to survive, or just island dwarfism?
Canto: Who knows, but it’s a good point. Island dwarfism occurred in the past, e.g. with elephants, but were they made less intelligent thereby? Surely not. And corvids have walnut-brains, with as many neurons as some monkey species. Size isn’t everything, check this out.
Jacinta: Please put it away. And nobody is saying that H naledi were dwarf hominins. Anyway, the major takeaway, comme on dit, is that this is just the beginning for Homo naledi. They need to be more disciplined about their claims, and maybe Berger’s enthusiasm, as evidenced in the Netflix film, is getting the better of his professional judgement. There will be further exploration of this challenging environment, and more and more incisive technology will be developed, as alway seems to happen.
Canto: So, in Gutsick Gibbon’s video we get to Berger at al’s response to the criticisms, with their main argument (about their contention that this was a deliberate burial) seeming to be that ‘there may be more types of burial on earth than are ever comprehended in your philosophy’, if I may murder Shakespeare, and that it might even be expected that a species far removed from H sapiens would have such quite different burial processes. And yet they’re claiming recognition of these more or less unrecognisable processes.
Jacinta: Yeah, it’s a bit like saying ‘there are aliens among us, but people are too dumb to see them – but we can see them’. Or maybe not. As Ms Gibbon points out, why didn’t the team stick with the original null hypothesis, that this was a sort of dumping ground, albeit a sorta respectful one, for their dead? That null hypothesis, by the way, might sit somewhere in the grey zone between, or sort of combining, the cultural and the natural.
Canto: Yes, Gutsick Gibbon weighs in on the question of whether we should look at sites of early hominins such as Australopithecus with more of a cultural null hypothesis than a natural one. She thinks ‘natural’, but I’d be more agnostic, partly because I’m too ignorant of palaeontology to take a strong stand, but also, as with my interest in bonobos, I’m prepared to take the widest possible view of culture.
Jacinta: Yes, in that disturbing chapter of Kindred which presents quite extensive evidence of Neanderthal cannibalism, and explores the reasons for such behaviour, Sykes suggests something in that cultural/natural grey zone. Again, she compares observed behaviour of bonobos and chimps:
For both bonobos and chimpanzees, the bodies of the dead evoke many emotions. Even if the process often begins with trauma and confusion, typically corpses shift to a liminal status; not alive, but equally not a lump of meat. They’re more intensively manipulated than hunted animals, and carried for longer. In some – if not all – cases, the eaters must know what and who they’re consuming. Cannibalism is very probably a powerful means by which individuals and groups process the impact not only of killings carried out on emotional impulses, but other deaths too. In other words, it’s about grieving.
Kindred, pp 309-10
Canto: Yes, I’m not sure what to think of that thesis, I’m not entirely convinced, but my mind is open and my brain’s not falling out. We’re only at the beginning, with H naledi and so much more…
References
https://www.netflix.com/au/title/81473682
Kindred: Neanderthal life, love, death and art, by Rebecca Wragg Sykes, 2020.
https://australian.museum/learn/science/human-evolution/homo-naledi/
language origins: some reflections
smartmouth
Jacinta: So a number of readings and listenings lately have caused us to think about how the advent of language would have brought about something of a revolution in human society – or any other society, here or on any other planet out there.
Canto: Yes, we heard about orangutan kiss-squeaks on a New Scientist podcast the other day, and we’re currently reading Rebecca Wragg Sykes’ extraordinary book Kindred, a thoroughly comprehensive account of Neanderthal culture, which we’ve clearly learned so much more about in recent decades. She hasn’t really mentioned language as yet (we’re a little over halfway through), but the complexity and sophistication she describes really brings the subject to mind. And of course there are cetacean and bird communications, inter alia.
Jacinta: So how do we define a language?
Canto: Yeah, we need to define it in such a way that other creatures can’t have it, haha.
Jacinta: Obviously it evolved in a piece-meal way, hence the term proto-language. And since you mentioned orangutans, here’s a quote from a 2021 research paper on the subject:
Critically, bar humans, orangutans are the only known great ape to produce consonant-like and vowel-like calls combined into syllable-like combinations, therefore, presenting a privileged hominid model for this study.
And what was the study, you ask? Well, quoting from the abstract:
… we assessed information loss in proto-consonants and proto-vowels in human pre-linguistic ancestors as proxied by orangutan consonant-like and vowel-like calls that compose syllable-like combinations. We played back and re-recorded calls at increasing distances across a structurally complex habitat (i.e. adverse to sound transmission). Consonant-like and vowel-like calls degraded acoustically over distance, but no information loss was detected regarding three distinct classes of information (viz. individual ID, context and population ID). Our results refute prevailing mathematical predictions and herald a turning point in language evolution theory and heuristics.
Canto: So, big claim. So these were orangutan calls. I thought they were solitary creatures?
Jacinta: Well they can’t be too solitary, for ‘the world must be orangutan’d’, to paraphrase Shakespeare. And interestingly, orangutans are the most tree-dwelling of all the great apes (including us of course). And that means a ‘structurally complex habitat’, methinks.
Canto: So here’s an even more recent piece (December 2022) from ScienceDaily:
Orangutans’ tree-dwelling nature means they use their mouth, lips and jaw as a ‘fifth hand’, unlike ground-dwelling African apes. Their sophisticated use of their mouths, mean orangutans communicate using a rich variety of consonant sounds.
Which is interesting in that they’re less close to us genetically than the African apes. So this research, from the University of Warwick, focused a lot on consonants, which until recently seemed quintessentially human productions. Researchers often wondered where these consonants came from, since African apes didn’t produce them. Their ‘discovery’ in orangutans has led, among other things, to a rethinking re our arboreal past.
Jacinta: Yes, there’s been a lot of focus recently on vowel and consonant formation, and the physicality of those formations, the muscles and structures involved.
Canto: Well in this article, Dr Adriano Lameira, a professor of psychology who has long been interested in language production, and has been studying orangutans in their natural habitat for 18 years, notes that their arboreal lifestyle and feeding habits have enabled, or in a sense forced, them to use their mouths as an extra appendage or tool. Here’s how Lameira puts it:
It is because of this limitation, that orangutans have developed greater control over their lips, tongue and jaw and can use their mouths as a fifth hand to hold food and manoeuvre tools. Orangutans are known for peeling an orange with just their lips so their fine oral neuro-motoric control is far superior to that of African apes, and it has evolved to be an integral part of their biology.
Jacinta: So they might be able to make more consonantal sounds, which adds to their repertoire perhaps, but that’s a long way from what humans do, putting strings of sounds together to make meaningful ‘statements’. You know, grammar and syntax.
Canto: Yes, well, that’s definitely going to the next level. But getting back to those kiss-squeaks I mentioned at the top, before we get onto grammar, we need to understand how we can make all the sounds, consonantal and vowel, fricative, plosive and all the rest. I’ve found the research mentioned in the New Scientist podcast just the other day, which compares orangutan sounds to human beatboxing (which up till now I’ve known nothing about, but I’m learning). Dr Lameira was also involved in this research, So I’ll quote him:
“It could be possible that early human language resembled something that sounded more like beatboxing, before evolution organised language into the consonant — vowel structure that we know today.”
Jacinta: Well that’s not uninteresting, and no doubt might fit somewhere in the origins of human speech, the details of which still remain very much a mystery. Presumably it will involve the development of distinctive sounds and the instruments and the musculature required to make them, as well as genes and neural networks – though that might be a technical term. Neural developments, anyway. Apparently there are ‘continuity theories’, favouring gradual development, probably over millennia, and ‘discontinuity theories’, arguing for a sudden breakthrough – but I would certainly favour the former, though it might have been primarily gestural, or a complex mixture of gestural and oral.
Canto: You’d think that gestural, or sign language – which we know can be extremely complex – would develop after bipedalism, or with it, and both would’ve evolved gradually. And, as we’re learning with Neanderthals, the development of a more intensive sociality could’ve really jump-started language processes.
Jacinta: Or maybe H sapiens had something going in the brain, or the genes, language-wise or proto-language-wise, that gave them the competitive advantage over Neanderthals? And yet, reading Kindred, I find it hard to believe that Neanderthals didn’t have any language. Anyway, let’s reflect on JuLingo’s video on language origins, in which she argues that language was never a goal in itself (how could it be), but a product of the complexity that went along with bipedalism, hunting, tool-making and greater hominin sociality. That’s to say, social evolution, reflected in neural and genetic changes, as well as subtle anatomical changes for the wider production and reception of sounds, perhaps starting with H ergaster around 1.5 million years ago. H heidelbergensis, with a larger brain size and wider spinal canal, may have taken language or proto-language to another level, and may have been ancestral to H sapiens. It’s all very speculative.
Canto: Yes, I don’t think I’m much qualified to add anything more – and I’m not sure if anyone is, but of course there’s no harm in speculating. Sykes speculates thusly about Neanderthals in Kindred:
Complementary evidence for language comes from the fact Neanderthals seem to have had similar rates of handedness. Tooth micro-scratches and patterns of knapping on cores [for stone tool-making] confirm they were dominated by right-handers, and this is also reflected in asymmetry in one side of their brains. But when we zoom in further to genetics, things get increasingly thorny. The FOXP2 gene is a case in point: humans have a mutation that changed just two amino acids from those in other animals, whether chimps or platypi. FOXP2 is definitely involved with cognitive and physical language capacity in living people, but it isn’t ‘the’ language gene; no such thing exists. Rather it affects multiple aspects of brain and central nervous system development. When it was confirmed that Neanderthals had the same FOXP2 gene as us, it was taken as strong evidence that they could ‘talk’. But another, subtler alteration has been found that happened after we’d split from them. It’s tiny – a single protein – and though the precise anatomical effect isn’t yet known, experiments show it does change how FOXP2 itself works. Small changes like this are fascinating, but we’re far from mapping out any kind of genetic recipe where adding this, or taking away that, would make Neanderthals loquacious or laconic.
Rebecca Wragg Sykes, Kindred: Neanderthal life, love, death and art, pp 248-9
Jacinta: Yes, these are good points, and could equally apply to early H sapiens, as well as H ergaster and H heidelbergensis. Again we tend to think of language as the full-blown form we learn about in ‘grammar schools’, but most languages today have no written form, and so no fixed grammar – am I right?
Canto: Not sure, but I understand what you’re getting at. The first English grammar book, more like a pamphlet, was published in 1586, when Shakespeare was just starting out as a playwright, and, as with ‘correct’ spelling and pronunciation, would’ve been politically motivated – the King’s English and all.
Jacinta: Queen at that time. Onya Elizabeth. But the grammar, and the rest, would’ve been fixed enough for high and low to enjoy Shakespeare’s plays. And to make conversation pretty fluid.
Canto: Yes, and was handed down pretty naturally, I mean without formal schooling. It’s kids who create new languages – pidgins that become creoles – when necessity necessitates. I read that in a Scientific American magazine back in the early eighties.
Jacinta: Yes, so they had the genes and the neural equipment to form new hybrid languages, more or less unconsciously. So much still to learn about all this…
Canto: And so little time….
References
Kindred: Neanderthal life, love, death and art, by Rebecca Wragg Sykes, 2021
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8478518/
https://www.sciencedaily.com/releases/2022/12/221220112426.htm
https://www.sciencedaily.com/releases/2023/06/230627123117.htm
https://en.wikipedia.org/wiki/Origin_of_language
https://humanorigins.si.edu/evidence/human-fossils/species/homo-heidelbergensis
humans and neanderthals and chimps and bonobos
We now know for sure that humans and neanderthals interbred. How much, we don’t know, nor do we know the nature of the interbreeding. The spectrum presumably goes from love and flowers to warfare slaughter and rape, and I recently heard one pundit arguing for the latter option, and I tend to agree, especially given what information ancient DNA is providing about human populations over the last 50,000 years or so – that’s to say, it appears that it was much less a case of cultures and practises spreading from one place to another than populations replacing earlier populations. And it may well be that we’ll get a more gory-detail picture of human-neanderthal intimacies in the foreseeable.
We’ve also learned that chimps and bonobos bonked after their separation due to the creation of the Congo River between one and two million years ago. I wish I’d been there to see it. My guess is that would’ve been far less traumatic, though perhaps not too lovey-dovey either.
So if we accept that violence was involved – who were the perps and who the victims? My feeling is that humans were the rapists, for the simple reason that we’re still here. Neanderthals disappeared some 40,000 years ago, though a remnant population appears to have survived in the Iberian Peninsula for another few thousand years. With chimps and bonobos it was probably more fifty-fifty, though I’m prepared to accept that nothing is ever that simple.
The fact that many of us – I don’t know about me – have some neanderthal DNA is probably a mixed blessing (some genes for absorbing sunlight may have predisposed us to skin cancer, others may have affected our ability to process carbs), but it hasn’t prevented us from quadrupling our population in the last century. And since we’ve produced the first whole-genome sequence of the neanderthal genome, they’ll soon be back with us, so no worries. Unfortunately, their memories of what we did to them will have been wiped, but we’re working on it.
Seriously, humans most likely were one of many contributors to neanderthal extinction. The two species shared similar European territories for the last few millennia before their disappearance, with human numbers apparently growing as neanderthals dwindled. Maybe they were out-competed in hunting big game, and small, as their diets would’ve been more or less identical to ours. Studies of neanderthal teeth from different environments (north-west and south-west Europe) indicate that they were opportunistic dieters, eating more meat in some regions, less in others, not all-out carnivores as previously thought, so this brings them even closer in line with humans, and in competition with them when habitats overlapped. And if anything, ancient DNA is telling us that our human ancestry was even more violent than previously thought – and we’ve long known how bad it was.
We don’t have any direct evidence that modern humans killed neanderthals, and we may never have such evidence. Professor Chris Stringer of London’s Natural History Museum argues that, as we now know that both species inhabited Western Europe for about 10,000 years before neanderthals died out, there was more likely a kind of awkward balance between the two species for much of that time. So, maybe killing but not outright extermination. Of course the same can be said for the large mammals that humans hunted. There was never any intention to exterminate them, but the pressure they were put under did for them in the end.
With chimps and bonobos, that seems to me even more of a mystery. What does a chimp look like to a bonobo, and vice versa? Most of us wouldn’t be able to tell one from the other, but that’s because we’re humans. In the past, Europeans used to say that all Chinese looked the same. Back in Darwin’s day and before, the people of Africa, Australia and Indonesia were collectively termed ‘savages’ by ‘white’ people. It’s taken a while for us dumb humans to become more discriminating. So it’s hardly surprising that bonobos weren’t recognised as a separate species from chimps until well into the twentieth century. Speciation itself is a rather more complicated and questionable affair than it was thought to be in the time of Linnaeus – and it wasn’t particularly simple then. Here’s an interesting quote from a Science article on chimp-bonobo interbreeding:
These findings come on the heels of other genome analyses—such as between coyotes, dogs, and wolves—showing such gene flow between species. “The more we look at genomes, the more it seems to be found,” [Professor Jim Mallet] says. “It’s going to be pretty common,” he predicts.
An article in earth.com, a popular science site, linked below, provides a summary of the physical and social differences between bonobos and chimps, though I can’t vouch for its accuracy – for example it claims that bonobo males and females are ‘much closer in size’ than chimp males and females. I’d always thought that the sexual dimorphism difference was slight, now I’m not so sure. Another interesting difference, that I’d not noticed before in my reading, is that bonobos have dark faces from birth, whereas chimps’ faces are lighter, and darken with age. I can well believe though that there are individual differences, in this as in robustness and gracility, bonobos being in general more gracile. Of course, chimp males are more dominant, so I can well imagine chimp-bonobo interbreeding to be a violent affair. And with bonobo females tending to stick together it would’ve been difficult to pick off an isolated female. Perhaps we should build a few Pan-friendly bridges across the Congo River and see what happens….
References
https://www.americanscientist.org/blog/science-culture/neanderthals-in-prime-time
https://www.science.org/content/article/chimps-and-bonobos-had-flings-and-swapped-genes-past
https://www.earth.com/earthpedia-articles/chimpanzees-vs-bonobos-whats-the-difference/
a bonobo world, etc 17 – good and bad hierarchies, human superiority and extinction threats
Robert Sapolsky on hierarchies – always worth listening to
One might say that bonobo society isn’t democratic, it’s hierarchical. But of course being hierarchical isn’t the opposite of being democratic. Every human society has been and is hierarchical. The hierarchy in earliest human times was probably based on raw prowess in providing resources and maintaining effective order in the group, the tribe, the village. Whoever managed to do so obtained prestige for himself, his family or breeding partners and his heirs, until such time as it all fell apart and competitors proved more effective. History, some former toff wrote, is a graveyard of aristocracies, but as human society became more formalised, those aristocracies often survived beyond their utility (to everyone but the aristocratic clique), as witness various hereditary power systems. Arguably the most unequal and rigid hierarchies were based on land ownership and control, when societies were largely agricultural, in feudal Europe and no doubt elsewhere. The more one family was able to concentrate power in its hands, as in medieval Britain and Czarist Russia, the more steps there would be in the ladder to the bottom, where the majority slaved away.
Nowadays, of course, we’re more slaves to our devices than to any human overlords. Most of us have never seen a harvest, but our homes are full of fruits and wines, basics and treats. Where our ancestors were treated as little more than effluent, we now feel ourselves to be relatively affluent, even with part-time work in service or tech industries. Where our forebears worried about the breadline, we’re more concerned about our waistline, and where we’ll put all our stuff. In his indispensable book The origin of feces (I had to buy it), David Waltner-Toews points out that, with some 7.5 billion human apes on the planet, we’re producing over 400 million tonnes of shit per year. Add to that our ever-increasing loads of sheepshit, bullshit, horseshit and chickenshit, and the figures for these are as mucky as the topic, and you might start to worry whether it’s the effluent of affluence that will finally bury us.
However, the prospect of spaceship Earth gradually filling up with the brown-and-yellow, or any other stuff, shouldn’t concern us, not because it’s all more or less biodegradable, but because spaceship Earth is just a bad metaphor, according to David Deutsch in The beginning of infinity. For Deutsch, the problem with the metaphor is its emphasis on finite resources, finite space, finite everything, and the idea that we humans are abusing the spaceship’s finite ‘design’. Deutsch is a boundless admirer of Jacob Bronowski and his 70s series ‘The ascent of man’, by which he means we human apes. Basically, Deutsch and Bronowski share the vision of a Danish prince written about some centuries ago:
What a piece of work is a man! How noble in reason, how infinite in faculty! In form and moving how express and admirable! In action how like an angel, in apprehension how like a god! The beauty of the world. The paragon of animals.
There seems to have been a bit of sarcasm at play there, but Deutsch is very much an optimist about human capacities, as his book’s title implies. The ascent of human apes isn’t like an ascent to the mountain’s summit, even less up the stairway to heaven, it’s the rise and expansion into a human-created infinity of invention and creation – a forever bubble blown out of human ingenuity, as progress accelerates and earth-boundness becomes hide-boundness and shit turns to sugar through the magic of science that is not magic.
And yet there are still human hierarchies, on an individual and even a national level. There are the OECD nations, for example, and those who don’t make the grade. There are the G8 or G7 nations and the not-so G7 nations. And there are the stateless and the non-nationalists, who might sometimes wish they were bonobos. Or would if they only knew…
Meanwhile, bonobos, hierarchical but also inclusive. Huddled together lovingly, mostly, and besieged, perhaps without knowing it. Did the last Neanderthals, perhaps huddled together in Gibraltar’s caves, know, or have any inkling, that they were the last? The African Wildlife Foundation (AWF) describes bonobos as Africa’s forgotten ape. Many people I know hadn’t even heard of them. It might well be their remoteness, compared to chimps. The southern bank of the Congo bears little resemblance to la rive gauche of Paris, and long may it remain so, but for years the region has been threatened by human warfare, slash and burn agriculture, and bushmeat hunting. The current wild population is hard to assess, but it is at least larger than perhaps the smallest ethnic group of humans, the Samaritans, who number less than a thousand. The Samaritans, however differ from bonobos in that their numbers are very gradually rising, without the need for them to be protected in zoos. Bonobos also manage to be charitable without religion.
Truly the threats to the bonobo community are no laughing matter, and I hope in my way to provide them with a pinch more of publicity. There’s competition of course. The solitary orang-utans of Sumatra and Borneo are under severe threat from deforestation and palm oil production, and Madagascar’s unique biodiversity is being devastated, again by slash and burn agriculture, as well as mining, climate change, invasive species, overharvesting and habitat fragmentation. Andy Isaacson writes about it in Cosmos magazine:
Madagascar’s endemic lemurs are now the most threatened group of primates on Earth, and nearly all of its species (94%) are at risk of extinction because of habitat loss and unsustainable hunting.
As always, there are human heroes, local and international, struggling to protect and improve the lives of these cousins of ours. Bonobos are facing an upsurge of hunting, according to AWF’s Jacqueline Conciatore:
For a long time, local taboos against hunting bonobos, who are so human-like, protected the peaceable apes. But those mores are dropping off under the influence of cultural outsiders and with tradition’s weakening hold on the young. Today, commercial bushmeat hunting, supported by ever more trade routes, joins habitat loss as a top threat to bonobos. Some researchers estimate that tons of bushmeat are extracted daily in bonobo range areas. The number of bonobos killed for bushmeat is limited compared to other species, but because bonobos reproduce slowly, bushmeat hunting poses a dire threat.
Spaceship Earth may seem ever-expandable for the all-conquering, infinitely capable human ape, and of course I accept that we aren’t under threat here in the way that the Ehrlichs’ book The Population Bomb notoriously predicted, but it’s notable that David Deutsch makes no mention of the plight of other species, let alone other apes, in his book about the future. Perhaps we can do without them?
References
https://en.wikipedia.org/wiki/Samaritans#Demographics
Andy Isaacson, ‘Food to save Madagascar’s future’, in Cosmos, issue 88
David Waltner-Toews, The origin of feces, 2013
David Deutsch, The beginning of infinity, 2011
Human ancestry 2 – a meander through a couple of million years’ time and a world of space
Man is descended from a hairy, tailed quadruped, probably arboreal in its habits.
Charles Darwin
So in this second post I’ll take a little look at Paranthropus and then try to make sense of the move from Australopithecus whateva to Homo whateva, and so on….
There’s a lovely vid about Paranthropus here, which I’ll take much of the following from. There are three known species, P aethiopicus (about 2.7 to 2.3 mya), P boisei (2.3 to 1.4 mya), both only found so far in eastern Africa, and P robustus (2 to 1.2 mya), in southern Africa. They’re all robust species, as opposed to the gracile species A africanus. They have large cheekbones, jaws and teeth, and a prominent sagittal crest across the top of the cranium, a feature shared by gorillas and orang-utangs, and which evolved to attach strong chewing muscles down to the jaw. Apart from these robust characteristics, they shared many features with australopithecines, and have even been defined as robust australopithecines by some. It’s always difficult to split up (or lump together) specimens when only small fragments are found, so there’s a hunt on for more, and bigger, bits and pieces. From what they’ve got, though, it’s estimated that they had a cranial capacity of 475-545 cc, not much more than the average chimp, with a height of about 156cm (just over 5 feet) and a weight of 40-50kg. Smallish perhaps, but I’d be willing to bet they had a pretty impressive muscle to fat ratio. They also appear to have been sexually dimorphic to a greater degree than humans, suggestive of dominant males fighting over females, as in the case of gorillas. There’s also some evidence that the females lacked or had a less prominent sagittal crest.
How are the Paranthropus species related to modern humans? Surprise surprise, we don’t know, and the pathways to and between the various types of Homo just get more complicated. They may simply have died out, as the more recent Neanderthals did. Researchers desperately await more finds, and more techniques for connecting the dots.
So, leaving Paranthropus behind, it’s clear from my last post on the subject that tracing the path from our common ancestor with bonobos (my fave ape) has been a fraught process of speculation and disputation, but of course we have no choice but to keep on trying to trace that path. So, what’s the most recently-lived species of Australopithecus, and the most ancient of the Homo species, as far as we know?
The species A africanus and A sediba seem currently to be in competition to be the immediate ancestor to Homo habilis along the pathway to H sapiens, though there may have been an intermediate, as yet undiscovered, species.
A africanus is known from four sites, all in South Africa, but dating the specimens has been difficult and controversial. The first discovery, the Taung child (1925) is still not clearly dated, and claims for it suffered at the time of its discovery, and for decades afterwards, due to the Piltdown hoax, which I won’t go into here. However, in the mid 1930s the first adult australopithecine was found, and eventually given the A africanus moniker. Evidence of bipedality in this and another adult female, found in 1947, together with evidence of a cranial capacity of about 485 cc for both, was striking evidence that bipedality long preceded brain growth (it has since been mooted as a result of reduced forestation and increased savannah-like environments through climate change, though bipedal traits seem to have existed even before this). A lack of facial projection in these specimens was suggestive of advancement towards modern humanity. And just by the bye, evidence of tool-making among hominins now goes back to 3.4 mya, associated with the A afarensis species. A fourth specimen, ‘Little Foot’, dated to around 3.7 mya, was found in the nineties, but there’s debate about whether it belongs to A africanus or a ‘new’ species, A prometheus (actually suggested by Raymond Dart decades ago). There’s an interesting piece on this here.
I wouldn’t want to be quoted on this, but it seems that the A africanus fossil of a skull now known as ‘Mrs. Ples’ is the most recent A africanus fossil ever found, dated to about 2mya. But what about A sediba? This is the most recently discovered australopithecene, mostly associated with Lee Berger (and his young son), who discovered the first bones in 2008, in South Africa. It has been argued, by its discoverers, to be the most likely transitional species between A africanus and either Homo habilis or H erectus (and it should be noted that many consider H (or A) habilis to be an australopithecine, its placement as Homo being largely based on the use of flaked stone tools, at a time when tool use by australopithecines wasn’t known).
So I think I’ll skip this controversy for now, as I want to get to the more recent radiation of Homo species. Having said that, immediately I start looking at the earliest forms given the Homo moniker, such as H habilis, H erectus and H ergaster, I encounter vast uncertainty and controversy, not to mention my own ignorance. I’ve already discussed H habilis; H ergaster (1.9 to 1.4 mya), according to Wikipedia, ‘is now mostly considered either an early form, or an African variety, of H erectus‘. Oh dear, I thought H erectus was African!
In fact, the first fossils identified with H erectus were found in Eurasian Georgia and in China, but the species may have back-migrated to Africa. Or maybe not. I’m on the verge of giving up here, but I’ll extricate myself from the mess by listing and briefly discussing the various forms of Homo that have been postulated. These aren’t necessarily in chronological order.
- H habilis (approx 2.1-1.5mya) – short but with longer arms compared to modern humans, with a cranial capacity of around 700 cc. Used stone tools. Relatively robust, compared to H ergaster. Contested classification. Probably co-existed with H erectus. Only found in Africa.
- H ergaster (approx 1.9-1.4mya) – I’ve used the Wikipedia existence range here, but the Australian museum suggests that arguments about existing classification of specimens may extend that range up to 700,000 ya. They also point out that some don’t accept this classification at all, preferring H erectus. They were relatively hairless and more closely resembled modern humans than earlier types. Possible specimens found in modern Kenya, Ethiopia, South Africa, and most notably in Georgia (Eurasia), which suggests first emergence of early humans from Africa occurred about 1.7mya. Cranial capacity, about 860cc .
- H erectus (approx 1.8mya- 100,000ya?) – first found in Java, other specimens found in Indonesia, China and Africa. Short and stocky with heavy brow ridges. Sometimes hard to separate from H ergaster, especially the African specimens. H erectus is now more widely believed to be a side-branch, and H ergaster our more direct, if more ancient, ancestor. Cranial capacity about 1050cc.
- H rudolfensis (approx 2.4mya- 1.8mya) – specimens found in modern Malawi and Kenya. A contested classification, could be lumped in with H habilis. There is always a difficulty when dealing with limited specimens, which might be atypical, juvenile or of unknown gender. Anyway, estimated cranial capacity, about 750cc. Size and shape insufficiently known.
- H heidelbergensis (c700,000-300,000 ya) – evolved in Africa, but in Europe by 500,000 ya (African fossils are mostly older). Lived and worked in co-operative groups, using a variety of tools. Specimens found in England, France and Spain as well as in the region of Heidelberg, Germany. Possibly as far east as northern India. Also in Zambia and South Africa. Physically tall, up to 180 cms, suggesting descent from H ergaster. Brain capacity approx 1250cc.
- H neanderthalensis (?800,000-40,000 ya) – some have argued that they were around as recently as 28,000 years ago. The first fossil was found in the 1820s, and was the first fossil of any extinct hominin ever found. Their cranial capacity, at 1500cc, is larger than that of H sapiens, not surprisingly due to their larger overall build (shorter but much more solid). No specimens found as yet in Africa, but a large number of finds throughout Europe and the Middle East (and possibly in China) allow us to build a clearer picture of Neanderthals than any other extinct hominin. They used a variety of tools, which they may have obtained through trade with modern humans. They wore animal hides and used fire for warmth, cooking and protection. Physically they were thickset, with heavy brow ridges and a relatively receding forehead, a forward-projecting face, a large, broad nose, and strong neck muscles. It’s now known, of course, that they interbred to some degree with modern humans, but it’s also likely that they competed with them for scarce resources, especially during ice ages. Though we don’t now consider them to be ‘nasty, brutish and short’ it may well be that the greater resourcefulness of H sapiens hastened their demise.
- H rhodesiensis (c800,000-120,000 ya) – now generally seen as an African subspecies of H heidelbergensis, with specimens found in Rhodesia/Zambia, Ethiopia and Tanzania.
- H cepranensis (c900,000-800,000 ya) – based on one fossil skull cap, or calvaria, unearthed near Ceprano, Italy in 1994. Others are for H heidelbergensis. The dating is also highly contested, with some arguing for around 450,000 ya. There’s probably quite a few more of this sort – but every new find is exciting.
- H denisova (? – 15,000 ya) – This isn’t an agreed taxonomic title, but the Denisovan finds are certainly exciting, with mitochondrial DNA being recovered from the first find (in a Siberian cave), the finger-bone of a juvenile female (how do they know that??). Other specimens have been found in the same cave, and another has been found in Tibet. There’s not enough material for us to picture this species, but the DNA tells us that they interbred with Neanderthals, and to a lesser degree with Melanesians, Papuans and Aboriginal Australians.
- H floresiensis (c190,000-50,000 ya) – found only on the Indonesian island of Flores. Another exciting, and puzzling, recent find. Could they have been killed off by those passing though on their way to Australia? Researchers are still hoping to recover mitochondrial DNA from the most recent specimens. Physically, these were unique humans with a very small stature and a cranial capacity of 380cc (chimp size), though with an enlarged Broadman area 10, which is associated with complex cognitive abilities. Other skull features, though, suggest a primitiveness going back more to H erectus. Tools found at the site have raised controversy. Do they belong to H floresiensis? They don’t easily equate with such a small brain. There is no precedent. Much still to be learned.
So I’ve raised far more questions for myself than I’ve answered. Hope to come back to this topic in future, with a focus on bipedality, climate effects, the beginnings of ‘culture’, and migration, among other things.
References
https://australianmuseum.net.au/learn/science/human-evolution/ (a great site, with links to details on particular species)
Paranthropus evolution (video), by Stefan Milo, 2019
https://en.wikipedia.org/wiki/Australopithecus
https://en.wikipedia.org/wiki/Australopithecus_africanus
https://en.wikipedia.org/wiki/Australopithecus_sediba
https://en.wikipedia.org/wiki/Homo_ergaster
http://humanorigins.si.edu/evidence/human-fossils/species/homo-habilis