Archive for the ‘evolution’ Category
stuff on punctuated equilibrium and organic complexity
isolation, strong selection, rapid change – an example of peripatric speciation
I’ve read a few books by Steven Jay Gould, and have found them sometimes a bit heavy-handed and clever-clever, though I’m sure I’ve learned a lot from them. I’ve also strongly disagreed with his notion of NOMA or non-overlapping magisteria, and have written about it in the long ago. The notion didn’t last long, it seems. So I’m wondering about how the concept of punctuated equilibrium, developed by Gould and others back in the day, is faring.
The idea was first proposed by Gould and Niles Eldredge in 1972. The PBS evolution library puts it this way:
… species are generally stable, changing little for millions of years. This leisurely pace is “punctuated” by a rapid burst of change that results in a new species and that leaves few fossils behind. According to this idea, the changes leading to a new species don’t usually occur in the mainstream population of an organism, where changes wouldn’t endure because of so much interbreeding among like creatures. Rather, speciation is more likely at the edge of a population, where a small group can easily become separated geographically from the main body and undergo changes that can create a survival advantage and thus produce a new, non-interbreeding species.
This is strange and interesting. I had thought that the ‘rapid burst of change’ was considered to be due to a sudden change in external conditions, brought about by, say, a burst of volcanic activity, or a massive meteorite, or whatever caused the Cambrian explosion (of new life forms) over 500 million years ago. I might return to that shortly. The type of speciation mentioned above, in which there is separation and isolation, creating unique circumstances for diversification in small populations, is called peripatric speciation. It’s one of the four modes of speciation generally recognised, the others being allopatric, parapatric and sympatric. Peripatric speciation is described as ‘a special version of the allopatric speciation mode’. A good example of this allopatric speciation mode, it seems to me, is the separation of the ancestors of bonobos and chimps into these two species about two million years ago. To back me up here’s a quote from UC Berkeley’s Understanding Evolution website:
Allopatric speciation is just a fancy name for speciation by geographic isolation… In this mode of speciation, something extrinsic to the organisms prevents two or more groups from mating with each other regularly, eventually causing that lineage to speciate. Isolation might occur because of great distance or a physical barrier, such as a desert or river…
So to round this out, I must inform myself about parapatric and sympatric speciation, which means trying to put other people’s explanations into my own words. Parapatric speciation occurs when there’s no outside barrier to gene flow (the movement of genetic material, often in the form of individual carriers of genetic material, from one population to another). Think of human migration, where the mixing of genes might not be random, due to culture barriers, but of course the chances of mixing would be much greater than if there was no migration. Sympatric speciation involves a reduction of gene flow without distancing or physical barriers. In humans it could happen when a particular set of humans breeds only with others of that set. This would take a very long time, and for humans it would involve a very artificial situation, but it has been known to occur, though rarely, in some species of insects and fish.
So, back to punctuated equilibrium. That this concept has been explored, with some evidence found but also disputed, is perhaps an indication of how novel and complex the whole topic of evolution still is. We look for traces of evolution in the fossil record, but that record is piecemeal and easily subject to ‘contamination’ over time. To be honest, much of what I’ve read from the proponents of punctuated equilibria goes over my head, requiring, it seems, an understanding of macroevolution, cladogenesis, phyletic gradualism and much much more. So I’m at a crossroads, sort of. Should I just give up, or plough on, with my not very efficient plough? How important is the topic? I really don’t know.
Here’s an example of the problem, as I see it, from ScienceDirect.com:
Cladogenesis is a phenomenon of evolution that occurs by the divergence of taxa due to positive selection for the adaptation of sister populations from a common ancestor to different environments due to their anatomical, morphological, geographic, temporal, ecological, and/or ethological (behavioural) isolation.
Ah, so that’s what cladogenesis is! But really, what’s a clado (a clade?) and what are taxa? Who’s this being written for? Obviously not dilettantes like me. I’ve turned instead to videos, and found one by someone I know well – sort of. Robert Sapolsky, whose big books Behave and Determined I’ve read with great interest in recent years. Sapolsky gives the story of gradualism versus punctuated equilibrium a humorous twist, with the proponents of gradualism calling the punctuators ‘jerks’, while they in turn were called ‘creeps’. Maybe, but is this really a big issue? Isn’t it quite reasonable to assume that just as the Earth’s biosphere itself has changed gradually but with the odd convulsion along the way, both forms of speciation, or many forms, have occurred?
So I’ve finally found a more enlightening (for me) video, obviously made some time ago, because it featured both Gould, who died in 2002, and Eldridge talking about their work, in good old layperson terms.
Anyway, for me the controversy or non-controversy over punctuated equilibrium is nowhere near as interesting as the one highlighted by Gould in his 1996 book Life’s Grandeur:
The basic theory of natural selection offers no statement about general progress, and supplies no mechanism whereby overall advance might be expected. Yet both Western culture and the undeniable facts of a fossil record that started with bacteria alone, and has now produced exalted us, cry out in unison for a rationale that will place progress into the centre of evolutionary theory.
This is particularly fascinating/amusing for me, as it plays into the ‘directed evolution’ concept which seems to me to be the god-botherers’ last hope for their world-view, though it seems to rule out ‘young Earth creationism’, though you never know with these people. I recall the late Cardinal George Pell, Australia’s most controversial Catholic, trying to argue for God-directed evolution shortly before sex-based controversies caught up with him and he disappeared from public view. Unfortunately, you need to make scientific sense of what this God-thing is, given that our planet is only one of probably billions out there, each of which has its story to tell, as part of a 13.8 billion-year universe.
Gould tries to deal with this conundrum – the undirected nature of evolution, from the point of view of ‘progress’, and how this process has produced ‘exalted us’ – in the last 60 pages or so of Life’s Grandeur, but I find that his tendency to use verbose language really gets in the way of comprehension (the key seems to be a fixed boundary condition) – so much so that I prefer to look to other sources. A research article from 2000, ‘Evolution of biological complexity’, points out, fairly obviously, that the key is to effectively define and perhaps quantify complexity – a difficult task, it seems. After all, complexity is complex.
Definitions may vary and not everyone is likely to agree, but what this article focuses on is genomic complexity, and information – ‘the amount of information a sequence stores about its environment’. I’m not sure what’s meant by a sequence here – perhaps a sequence in an evolutionary chain. The article is long and, for me, forbiddingly mathematical, but as it concludes in the abstract..
We show that, because natural selection forces genomes to behave as a natural “Maxwell Demon,” within a fixed environment, genomic complexity is forced [my emphasis] to increase.
So what is a ‘Maxwell Demon’ (I do know that it comes from James Clerk Maxwell, and that it has to do with the second law of thermodynamics), and how has this ‘proof’ fared in the 14 years since it was published?
Does the emergence of complexity of life on Earth need to be explained? Some, of course, want to explain it in terms of ‘purpose’, opening the door to agency and all that stuff, but I’m not going there. Others might worry about it in terms of that pesky second law (entropy always increases), but then there are ‘closed systems’, such as the Earth’s biosphere, which temporarily act against the ‘growth’ of entropy. Don’t worry, life will become extinct here eventually, and the whole planet will fall apart – the centre doesn’t hold.
Darwin himself was a bit contradictory about this issue. Often he enjoyed, it seems, to point out the directionlessness (to coin a word?) of natural selection, as it seemed to stick in the craws of some, but more often he fell in with his own culture and class and wrote of savages and the less advanced, in at least pseudo-evolutionary terms.
Anyway, complexity has arisen, or evolved, on this planet, so I’ll try to think about it further, with the help of reading and listening to others, in my next post.
References
https://www.pbs.org/wgbh/evolution/library/03/5/l_035_01.html
https://evolution.berkeley.edu/modes-of-speciation/peripatric-speciation/
http://www.scholarpedia.org/article/Punctuated_equilibria
Stephen Jay Gould, Life’s Grandeur: the spread of excellence from Plato to Darwin, 1996
stuff on exaptation and Archaeopteryx
my photo of archaeopteryx, from London’s Natural History Museum
Through my various readings and researches, if they can be credited as such, I’ve from time to time come across the famous image of Archaeopteryx, a fossil (now the type specimen) of some sort of dinosaur-bird discovered in the early 1860s, and with some fanfare, I think, presented as proof of Darwin’s recently published thesis, On the Origin of Species (1859). Now, being an impoverished type, with an elementary scientific education, I’ve travelled little, and much of my reading has been from borrowed or scrounged titles, including the aforementioned work. However, a few years ago, due to a lucky and undeserved inheritance, I got to travel to London from my home in Australia, whereupon I paid a visit to the British museum. Wandering lonely as a cloud along the hallowed halls, I suddenly found myself face to face with the Archaeopteryx specimen so very occasionally but memorably depicted in the science texts previously perused, and I must say my heart skipped a beat. Not that I quite knew what all the fuss was about. It had something to do with missing links and flying dinosaurs and, as mentioned, confirmation of the controversial thesis.
Anyway a recent reading of the essay ‘Not necessarily a wing’, in Stephen Jay Gould’s Bully for Brontosaurus collection, has taken me back to Archaeopteryx, the first bird, as Gould calls it, though surely we can’t be certain about that. However the important point is that birds evolved from creatures that weren’t birds, and it likely wasn’t a sudden thing. As Gould describes it, arguments against Darwin’s theory, sometimes by evolutionists of a different stripe, questioned the development of features such as wings, and their usefulness before they were ‘developed’ enough to enable flight. Darwin responded with the concept of ‘functional shift’, more recently labelled ‘exaptation’, thanks to academic contributions from Gould himself, among others.
Wikipedia has it that ‘older potential avialans have [recently] been identified’. The term ‘avialan’, from Avialae (“bird wings”) ‘is a clade containing the only living dinosaurs, the birds, and their closest relatives’. In any case what’s more important is how flight developed in early dinosaurs. Archaeopteryx lived about 150 million years ago (the late Jurassic) and was about magpie-sized, but probably nothing like a modern bird in appearance. It had teeth, unlike modern birds, and a long bony tail, and various other features characteristic of dinosaurs. So it has been described as a transitional species. But what does this mean? Are we a transitional species? Isn’t every species transitioning in some way? (Add plug for transitioning to a bonoboesque humanity here).
What we can say is that Archaeopteryx was likely one of the first flying dinosaurs as well as the first bird or proto-bird, and we now have 12 separate fossils of the species. But of course discoveries continue. From Wikipedia,
… in recent years, the discovery of several small, feathered dinosaurs has created a mystery for palaeontologists, raising questions about which animals are the ancestors of modern birds and which are their relatives.
But let me return to this issue of exaptation – in this case, as regards wings and flight. Gould quotes from the 19th century dissenter vis-a-vis Darwin’s theory, St George Mivart, on the general problem:
Natural selection utterly fails to account for the conservation and development of the minute and rudimentary beginnings, the slight and infinitesimal commencements of structures, however useful those structures may afterwards become.
Mivart opted for a ‘comparatively sudden modification of a marked and important kind’, rather than incremental but still adaptive changes – that’s to say, changes naturally selected for, though not of course by any kind of design. But Darwin countered that these ‘sudden modifications’ smacked of the miraculous – ‘to admit all this is, as it seems to me, to enter into the realms of miracle, and to leave those of Science’.
Mivart worked hard to find large-scale modifications that might fit within an evolutionary framework, while at the same time Darwin had to work hard to show the adaptiveness of small-scale changes that might, over a long period, lead, for example, to flight. The organism would be gradually changed in terms of its hunting and feeding practices, for example, which would be incrementally selected for until the structural-anatomical changes led to an increasingly sustained ability to leave the ground for nutrition further afield and/or higher above ground.
Okay, this isn’t exactly what Darwin presents, which is change of function (functional shift – exaptation). I’m suggesting that the change itself would be so gradual as to be barely noticeable, functionally, except through the ‘compression’ of time afforded by our analyses of fossil records. However, unsurprisingly, analysts have been here before, as Gould’s essay tells us. In the case of insects, wing size compared to body size has been analysed carefully in recent decades, with respect to flight versus insulation or thermoregulation, and the results have favoured an exaptation model – first the advantages of thermoregulation, then as wings grew in proportion to body size, the advantages – and such advantages! – of flight.
The details here are complex almost beyond description – certainly beyond my ability to describe them – and we may perhaps never know whether Archaeopteryx is the direct descendant of modern birds or a cousin of that descendant. The Wikipedia article on the species is virtually book-length, with well over 100 references. The arguments run along similar lines regarding various human antecedents, with lumpers and splitters debating the position of Homo ergaster, Homo luzonensis et al. Gould points out, I think rightly, that evolutionary history is very bushy and human researchers are overly obsessed with finding direct, vertical lines of descent – ladders among the bushes, or transforming bushes into sets of ladders. The bushes themselves have their intrinsic interest and beauty.
References
Stephen Jay Gould, ‘Not necessarily a wing’, in Bully for Brontosaurus, 1991
bonobos, an outlier in the primate world, and yet…
any excuse for a nice bonobo pic
In trying to develop a bonobo world with human characteristics, or perhaps more realistically a human world with bonobo characteristics, I suspect it’s best not to start by disparaging the male (human) brain as ‘unevolved’ or distinctly inferior to that of the female – something I heard in an interview with a male psychotherapist recently. Firstly, it make no sense to say that a brain, or a human, or a dog, a dolphin or a donkey is ‘unevolved’. This is a fundamental misunderstanding of evolution, which is about ongoing change to most effectively adapt to a changing environment. And this includes social environments. The Andamanese, a tiny population living on scattered islands in the Bay of Bengal from about 25,000 years ago, and driven almost to extinction in the 18th and 19th centuries by the introduction of measles, influenza, pneumonia, and alcohol, have recovered somewhat and preserve their simple lifestyle via extreme hostility to interlopers, and are no more unevolved than were the ancient Hominins who once lived on the Indonesian island of Flores. It’s true, of course, that evolution can be competitive, and some species – or sub-species or cultures – can win out over others, but to describe this as due to being ‘more evolved’ rather over-simplifies matters. Each species evolves to survive and thrive in its own niche, and may thrive in that way for an eon, but may be swept away by another invasive species, or by relatively sudden climate change, or by very sudden events such as meteor showers or volcanic eruptions.
In the same interview, the psychotherapist described the male brain, including his own, as sick and in some sense mentally unbalanced compared to the female brain. And you can go onto YouTube and other sources to find dozens of mini-lectures and expert opinions on the male versus the female brain.
However, it might surprise people to know that there is no categorical difference between the male and female brain, at least not in the sense there is, usually, between a male and female body. Put another way, if a neurologist with decades of experience was given a disembodied brain and asked about its sex, she wouldn’t be able to say, categorically, whether it was male or female. There are statistical differences – males have, on average, more ‘grey matter’ (individual neurons) while females have more ‘white matter’ (myelinated axons connecting neurons) – but there is great diversity within this frame, which should hardly surprise us. Our brains develop within the womb, subject to the diet and environmental conditions of our mothers, and genetic and epigenetic factors have their role to play. In early childhood neural connections multiply rapidly in response to a multitude of more or less unique conditioning factors, and new connections continue to be made well into adulthood, resulting in more than eight billion tediously unique noggins clashing and combining in tediously unique ways.
So, to me, it’s behaviour that we need to start with. Of course I’m interested in the nervous system and the endocrine system of bonobos, but that’s because I’m first and foremost taken by their behaviour. I’m encouraged by what I see as changes in male behaviour in the WEIRD world, but then I was told recently that male violence against women is actually increasing. Of course these things are hard to measure as not all violence is reported, and the very concept of violence may be disputed, but a quick look at figures for Australia, which surely qualifies as a WEIRD nation, suggests that my sense of things is right:
Experiences of partner violence in the 12 months before the survey (last 12 months) remained relatively stable for both men and women between 2005 and 2016. However, between 2016 and 2021–22 the proportion of women who experienced partner violence decreased from 1.7% in 2016 to 0.9% in 2021–22.
Australian Institute of Health and Welfare (Australian Government)
Whatever one might think of these figures, there’s little evidence of an increase in male violence (against females), at least here, in this teeny WEIRD nation. So maybe it’s places like Australia, and New Zealand, far from some of the major global threats, slowly building a multi-ethnic culture (largely proof against the massive social divisions stifling the divided ‘USA’), an oasis of 26 million compared to the bonobo oasis of maybe 20 thousand, a region that still likes to think of itself as ‘young and free’, and prepared to experiment with our politics and culture, maybe it’s here that bonobo-style caring-and-sharing behaviour can start to make some headway (but of course even as I write this it strikes me as ridiculous).
The trouble, of course, is that it’s hard to focus on such a possible future without sex rearing its not-so-ugly head. In human culture we’re obsessed with beauty (both male and female) in a positive way (though bad luck if you happen not to be physically attractive), and obsessed with sex in a much more confused but largely negative way (‘licentiousness’, a very human term, is generally condemned in all societies). Do bonobos distinguish between each other in terms of ‘good looks’? If not, when did we, or our ancestors start to do so? There has of course been much talk of ‘sexual selection’ in anthropology, going back to Darwin, but in bonobo society, where female-female sex predominates but sex, generally in the form of mutual masturbation, occurs among and between all age groups and genders, sexual selection (for breeding purposes) would only occasionally operate. And after all, masturbation is about one’s own erogenous zones, which, like being tickled, are best aroused by another, no matter what they look like. Think of a dog masturbating on your leg.
One might argue that religion has a lot to answer for, in so firmly linking sex to shame and transgression, while another might argue, along with Freud, that sexual sublimation was a necessary prerequisite for human civilisation. I’m still trying to work out my own view on this, but I’d surmise that the link between sex and shame existed in humans long before the Abrahamic religions took it to extremes. And unfortunately, much of the online material on our history of sex and shame contains a lot of bollocks, so I’ve reached a dead end there.
So here’s some guesswork. It may have started with the wearing of minimal clothing to protect the reproductive parts, both from damage and from gawkers – out of sight, out of mind. Perhaps this was initiated by females, but more likely (in the case of female genitalia) by males. On this topic I’ve often read claims that pre-agricultural or non-agricultural societies were less patriarchal, and I’ve even adopted that view myself, but I suspect the difference was only in degree, not in kind.
As to patriarchy itself, consider this. Bonobos and chimps split from each other 2 million years ago, at most. From that time on, bonobos survived and thrived in a relatively circumscribed, densely forested region south of the Congo. Chimps on the other hand are more numerous and wide-ranging (with more varied habitats), and are currently divided into four sub-species, from the west to the east of sub-Saharan Africa, and their number in the wild, though hard to determine with any precision, is generally estimated as about ten times that of bonobos. And all chimps are patriarchal.
The dating of the CHLCA (the last chimpanzee-human common ancestor, and note that bonobos are excluded from this reference) has been a subject of ongoing debate and analysis. Here’s how Wikipedia puts it:
The chimpanzee–human last common ancestor (CHLCA) is the last common ancestor shared by the extant Homo (human) and Pan (chimpanzee and bonobo) genera of Hominini. Estimates of the divergence date vary widely from thirteen to five million years ago.
Obviously, this was before the chimp-bonobo divergence, and considering speculation by anthropologists that bonobo ‘female power’ might be linked to a more frugivorous diet and less of a hunting-killing lifestyle (due to their restriction to an area rich in fruits, nuts, seeds and small game), it seems likely that the CHLCA was already more patriarchally inclined. Consider also that the genus Homo sapiens, long believed to date to no more than 200,000 years ago, and arising in eastern sub-Saharan Africa, has recently been dated to over 300,000 years from remains found in faraway Morocco. That suggests the traversing of vast regions, and a diet much richer in meat than that of bonobos. So, while the hunter-gatherer term has been passionately disputed by some, it’s generally accepted – and it makes sense to me – that there was some division of labour, as implied by the term, and that it would likely be largely gender-based. So, our history, and our ancestry, has been almost entirely patriarchal.
However, this doesn’t define our future. Patriarchy is breaking down in the WEIRD world, albeit slowly. And there are, depressingly, many forces in opposition to female empowerment, especially in the non-WEIRD world. I’ll focus on that in my next post.
bonobos and humans – immanence and transcendence?
the struggle against scumbaggery
Canto: So, having heard recently that Indonesia is passing laws to criminalise sex outside of marriage, and that Uganda is passing laws to criminalise anyone who identifies as homosexual, I’m feeling a touch of despair about the future bonobo society with human characteristics that I intended to impose upon the globe in the next few weeks.
Jacinta: Well it’s interesting to note that Indonesia is a predominantly Moslem country, and Uganda is overwhelmingly Christian, but there’s no doubt that religious ideology is behind both of these developments.
Canto: Yes, the WEIRD world, which neither of these countries belong to, is becoming increasingly secular, so much so that S should be fitted into the acronym – a world of WEIRDS, perhaps? So I suppose I should limit my ambition to the WEIRDS of the world. But that not’s what I want to talk about today, though it is related, sort of. Remember Ferdinand Mount’s The subversive family, an attempt to argue that the family unit, and so monogamy, has always been the norm, and has managed to subvert all attempts to replace or diminish it? I’ve been thinking a bit about this lately, and wondering about the unknown history of Homo sapiens and their antecedents, and their socio-sexual relations and child-rearing, given that our closest living relatives, bonobos and chimps, are quite different from each other in these traits.
Jacinta: Yes, and neither of them are monogamous. It’s interesting, but hardly surprising, that we’re inordinately interested in the human side of the divide between us and the so-called HC-LCA (the Human-Chimpanzee Last Common Ancestor), but not so much in the chimp-bonobo side.
Canto: Well of course, and even with that inordinate interest we’re very far from working out our human ancestry going back any more than two million years or so, let alone their socio-sexual arrangements. Anyway we’re not as monogamous as we pretend to be, and no amount of government regulation, or religious devotion, is going to change that.
Jacinta: But it’s interesting that we hold to a monogamous child-rearing ideal, and I’m wondering if that’s always been the case, or how long it has been, or whether there’s a worthwhile alternative, as arguably suggested by our bonobo heroines.
Canto: Well I know that single parent families are on the rise in Australia, and no doubt throughout the WEIRDS world, and any stigma associated with this is waning, but I’m not sure that this is exactly a movement in the direction of human bonoboism. It seems to me that the key to bonobos’ attraction is a kind of multiple-parenting system – not so compartmentalised. Sharing the love.
Jacinta: Bonobo and chimp dads likely don’t know for sure who their kids are – I just can’t imagine that being okay for humans any time soon, or even longer than soon.
Canto: Good point, though it’d be great if we could nurture and delight in kids just for being kids, rather than our kids. And I can well imagine that being the case when we lived together in caves rather than wee domestic units. It takes me back to the kibbutzim idea that I learned about as a teenager, after years of feeling trapped in my parents’ loveless marriage. Communal parenting…
Jacinta: But without the socialism? Or the Jewishness for that matter…
Canto: Well most kibbutzim today are secular, and they’re still very much with us – well not exactly with us, as they’re on the other side of the world, but I’m not sure about the socialism. Is bonobo society socialist?
Jacinta: Well, that’s the thing. Kibbutzim are, I presume, rules-based, top-down forms of communal living, whereas bonobo society just happened, a relaxed, happy-seeming culture, with females bonding and looking out for each other and their offspring in a way that the males, over time, acceded to. Nothing forced or regulated about it. I’m done, frankly, with labels like socialism and capitalism. I mean, we’re the most socially constructed mammalian species on the planet, the key to our success if you like, and you can call that socialism I suppose. And we’re more thoroughly capitalist than any other species, capitalising on a massive number of other living resources to survive and thrive, not just through pure consumption but domestication and other manipulative practices.
Canto: Well said. But I still have a soft spot for the kibbutz idea, without Yom Kippur or Christmas, a thoroughly sciencey, sexy, smiley celebration of smart, sassy, sisterly communal living…
Jacinta: Not quite the bonobo world though, is it? Sounds more like dropping out. The original kibbutzim were based on land, and agriculture. And what would the bonobo world be without its forest lands and their simple resources? The world of WEIRDS wants so much more, a kind of eternal transcendence. To be more, to have more, to make more, to do more, to live more, as if it’s more satisfying to never be satisfied.
Canto: Hmmm. Thought-provoking, but I just wanted to focus on monogamy and child-rearing, and now you’ve given me a headache. I’m wondering though – because it niggles at the back of my mind, if the bonobo world would really work for us. Our success, if you want to call it that, is due to our endless ambition – caused presumably by those big brains of ours. To paraphrase Marx, those big brains have made us want to not just understand the world, but to change it. And boy have we ever fucking changed it.
Jacinta: Yeah, just ask those aurochs and quaggas and moas and dodos and passenger pigeons… oh but – we can’t.
Canto: Not to mention the millions of humans we slaughtered in wars, worked to death in mines and factories, and fucked to death for our entertainment, but then again, what a piece of work is a man, in apprehension how like a god! But a woman – maybe a woman is more than just a quintessence of dust. And if she is, maybe that little soupçon is just what humanity needs to flavour its thinking about the biosphere and its endless exploitation.
Jacinta: Yes well, don’t put all the responsibility onto us mate. And yet – we need plenty of adventurous spirit as well as a sense of ‘nobody left behind’ to navigate ourselves out of self-created disasters such as global warming, toxic work environments (both physical and mental), and species depletion. And I’m not saying this from some simplistic perspective of male traits admixed with female ones.
Canto: No because we’re already getting mixed up, in a good way. The WEIRDS are taking over the world – have taken over the world…
Jacinta: Yes, China is so western now, and so democratic…
Canto: Well, that’s actually half true. The term ‘western’ is surely the weakest link in the WEIRDS chain. I mean China’s difficult to analyse with its vast population, which means tons of poverty as well as tons of richesse. It has urbanised very rapidly, yet its rural and mostly poor population is still greater than the entire population of most countries. But if you take the rapidly educating and enriching and industrialising urban elites, you’ve got a pretty strong candidate for something equivalent to WEIRDness.
Jacinta: And then of course there’s the urban poor. But you’re right, the term ‘western’ has never made a lot of sense to me. EIRDS perhaps?
Canto: Not the most cromulent of acronyms. RIDES is at least a word, but… I think we’re stuck with WEIRD/S for the foreseeable. Anyway, I think we need to unshackle ourselves from patriarchal religion – I know the WEIRD world largely has, but I’m impatient. Doing so I think will enable more women to be part of the solutions to the problems we face, and the problems other species face because of us.
Jacinta: China and Japan are pretty secular these days, but how many female leaders have they had in the last century or so?
Canto: Yes it’s taking its time – China has now achieved female literacy and education levels that are pretty well equivalent to those of males, but perhaps education isn’t entirely equivalent to empowerment.
Jacinta: Under Xi’s dictatorship female empowerment has clearly gone backwards. Hopefully he’ll be dead soon, but he’s probably already trying to ensure another macho thug succeeds him. Women have absolutely zero power in today’s China. As for Japan, they were ranked 110th in the world for gender equality in 2019, and the sexism there is really stark, in spite of 70% of women being in the workforce. You’ll remember our semi-serious piece about bonobos not wearing stupid shoes, meaning stilettos? There was a ruckus just a few years ago (2019) about that fucked-up footwear, which went semi-viral worldwide, as reported in The Guardian:
Meanwhile, even something as apparently straightforward as being allowed to wear whatever shoes you like continues to prove tricky. In response to the #KuToo petition [the hash-tag puns on ‘shoes’ and ‘pain’], Japan’s minister of labour, Takumi Nemoto, told parliament that requiring high heels in the workplace was perfectly acceptable – sparking further outrage at the government of Shinzo Abe, whose “Womenomics” policy is supposedly attempting to bring more women into the workforce.
Canto: Presumably Mr Nemoto wasn’t wearing high heels when he said this, so WTF.
Jacinta: At least there was blowback, but not nearly enough. Sigh, the arc of progress is long, but it bends towards beating sense into blokey blokes, ou quelque chose comme ça.
Canto: Transcendence may not be imminent, but it’s eminently desirable, for the benefit and beautification of our immanent being…
References
Ferdinand Mount, The subversive family, 1982
https://en.wikipedia.org/wiki/Kibbutz
Gaia Vince, Adventures in the Anthropocene, 2014
Gaia Vince, Transcendence, 2019
Click to access shsconf_sschd2023_02001.pdf
https://www.theguardian.com/world/2022/oct/22/where-are-the-women-at-the-top-of-chinese-politics
a bonobo world 33: they don’t wear stillettos
understanding genomics 1 – mitochondrial DNA
Canto: So maybe if we got humans to mate with bonobos we’d get a more promising hybrid offspring?
Jacinta: Haha well it’s not that simple, and I don’t mean just physiologically…
Canto: Okay those species wouldn’t be much attracted to each other – though I’ve heard that New Zealanders are very much attracted to sheep, but that just might be fantasy. But seriously, if two species – like bonobos and chimps, can interbreed, why can’t bonobos and humans? And they’d don’t have to canoodle, you can do it like in vitro fertilisation, right?
Jacinto: Well, bonobos and chimps are much more closely related to each other than they are to humans. And if you think bonobo-human hybridisation will somehow create a female-dominant libertarian society, well – it surely ain’t that simple. What we see in bonobo society is a kind of social evolution, not merely a matter of genetics. But having said that, I’m certainly into exploring genetics and genomics more than I’ve done so far.
Canto: Yes, I’ve been trying to educate myself on alleles, haplotypes, autosomal and mitochondrial DNA, homozygotism and heterozygotism (if there are such words), single nucleotide polymorphisms and…. I’m confused.
Jacinta: Well, let’s see if we can make more sense of the science, starting with, or continuing with Who we are and how we got here, which is mostly about ancient DNA but also tells us much about the past by looking at genetic variation within modern populations. Let me quote at length from Reich’s book, a passage about mitochondrial DNA – the DNA in our mitochondria which is somehow passed down only along female lines. I’ve no idea how that happens, but…
The first startling application of genetics to the study of the past involved mitochondrial DNA. This is a tiny proportion of the genome – only approximately 1/200,000th of it – which is passed down from mother to daughter to granddaughter. In 1987, Allan Wilson and his colleagues sequenced a few hundred letters of mitochondrial DNA from diverse people around the world. By comparing the mutations that were different among these sequences, he and his colleagues were able to construct a family tree of maternal relationships. What they found is that the deepest branch of the tree – the branch that left the main trunk earliest – is found today only in people of sub-Saharan African ancestry, suggesting that the ancestors of modern humans lived in Africa. In contrast, all non-Africans today descend from a later branch of the tree.
Canto: Yes, I can well understand the implications of that analysis, but it skates fairly lightly over the science, understandably for a book aimed at the general public. To be clear, they looked at the same stretches of mitochondrial DNA in diverse people, comparing differences – mutations – among them. And in some there were many mutations, suggesting time differences, due to that molecular clock thing. And I suppose those that differed most – from who? – had sub-Saharan ancestry.
Jacinta: Dating back about 160,000 years, according to best current estimates.
Canto: The science still eludes me. First, how does mitochondrial DNA pass only through the female line? We all have mitochondria, after all.
Jacinta: Okay, I’ve suddenly made made myself an expert. It all has to do with the sperm and the egg. One’s much bigger than the other, as you know, because the egg carries nutrients, including mitochondria, the only organelle in your cytoplasm that has its own DNA. Your own little spermatozoa are basically just packages of nuclear DNA, with a tail. Our mitochondrial DNA appears to have evolved separately from our nuclear DNA because mitochondria, or their ancestors, had a separate existence before being engulfed by the ancestors of our somatic or eukaryotic cells, in a theory that’s generally accepted if difficult to prove. It’s called the endosymbiosis theory.
Canto: So mitochondria probably had a separate, prokaryotic existence?
Jacinta: Most likely, which could take us to the development, the ‘leap’ if you like, of prokaryotic life into the eukaryotic, but we won’t go there. Interestingly, they’ve found that some species have mitochondrion-related organelles with no genome, and our own and other mammalian mitochondria are full of proteins – some 1500 different types – that are coded for by nuclear rather than mitochondrial DNA. Our mitochondrial DNA only codes for 13 different types of protein. It may be that there’s an evolutionary process going on that’s transferring all of our mitochondrial DNA to the nucleus, or there might be an evolutionary reason for why we’re retaining a tiny proportion of coding DNA in the mitochondria.
Canto: So – we’ve explained why mitochondrial DNA follows the female line, next I’d like to know how we trace it back 160,000 years, and can place the soi-disant mitochondrial Eve in sub-Saharan Africa.
Jacinta: Well the term’s a bit Judeo-Christian (there’s also a Y-chromosomal Adam), but she’s the matrilineal most recent common ancestor (mt-MRCA, and ‘Adam’ is designated Y-MRCA).
Canto: But both of these characters had parents and grandparents – who would be somehow just as common in their ancestry but less recent? I want to know more.
Jacinta: To quote Wikipedia…
… she is defined as the most recent woman from whom all living humans descend in an unbroken line purely through their mothers and through the mothers of those mothers, back until all lines converge on one woman.
… but I’m not sure if I understand that convergence. It clearly doesn’t refer to the first female H sapiens, it refers to cell lines, haplogroups and convergence in Africa. One of the cell lines used to pinpoint this convergence was HeLa, the very first and most commonly used cell line for a multiplicity of purposes…
Canto: That’s the Henrietta Lacks cell line! We read The Immortal Life of Henrietta Lacks! What a story!
Jacinta: Indeed. She would be proud, if she only knew… So, after obtaining data from HeLa and another cell line, that of an !Kung woman from Southern Africa, as well as from 145 women from a variety of populations:
The published conclusion was that all current human mtDNA originated from a single population from Africa, at the time dated to between 140,000 and 200,000 years ago.
Canto: So mt-MRCA is really a single population rather than a single person?
Jacinta: Yeah, maybe sorta, but don’t quote me. The Wikipedia article on this gives the impression that it’s been sheeted home to a single person, but it’s vague on the details. Given the way creationists leap on these things, I wish it was made more clear. Anyway the original analysis from the 1980s seems to be still robust as to the time-frame. The key is to work out when all female lineages converge, given varied mutation rates. So, I’m going to quote at length from the Wikipedia article on mt-MRCA, and try to translate it into Jacinta-speak.
Branches are identified by one or more unique markers which give a mitochondrial “DNA signature” or “haplotype” (e.g. the CRS [Cambridge Reference Sequence] is a haplotype). Each marker is a DNA base-pair that has resulted from an SNP [single nucleotide polymorphism] mutation. Scientists sort mitochondrial DNA results into more or less related groups, with more or less recent common ancestors. This leads to the construction of a DNA family tree where the branches are in biological terms clades, and the common ancestors such as Mitochondrial Eve sit at branching points in this tree. Major branches are said to define a haplogroup (e.g. CRS belongs to haplogroup H), and large branches containing several haplogroups are called “macro-haplogroups”.
So let’s explain some terms. A genetic marker is simply a DNA sequence with a known location on a chromosome. A haplotype or haploid genotype is, as the haploid term suggests, inherited from one rather than both parents – in this case a set of alleles inherited together. SNPs or ‘snips’ are differences of a single nucleotide – e.g the exchange of a cytosine (C) with a thymine (T). As to the rest of the above paragraph, I’m not so sure. As to haplogroups, another lengthy quote makes it fairly clear:
A haplogroup is…. a group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation.More specifically, a haplogroup is a combination of alleles at different chromosomal regions that are closely linked and that tend to be inherited together. As a haplogroup consists of similar haplotypes, it is usually possible to predict a haplogroup from haplotypes. Haplogroups pertain to a single line of descent. As such, membership of a haplogroup, by any individual, relies on a relatively small proportion of the genetic material possessed by that individual.
Canto: Anyway, getting back to mt-MRCA, obviously not as memorable a term as mitochondrial Eve, it seems to be more a concept than a person, if only we could get people to understand that. If you want to go back to the first individual, it would be the first mitochondrion that managed to synthesise with a eukaryotic cell, or vice versa. From the human perspective, mt-MRCA can be best conceptualised as the peak of a pyramid from which all… but then she still had parents, and presumably aunts and uncles…. It just does my head in.
References
https://www.genome.gov/genetics-glossary/Mitochondrial-DNA
https://en.wikipedia.org/wiki/Mitochondrial_Eve
https://en.wikipedia.org/wiki/Haplogroup
Did bonobos do it with chimps? Well, duh
bonobos or chimps? Or both? Or neither? What’s in a name…?
Canto: So we’ve been learning than we did it with Neanderthals, and that Neanderthals did it with Denisovans, and I remember hearing an anthropologist or palaeontologist saying that it’s likely that our split with our last common ancestor with chimps and bonobos – they call it the CHLCA (chimp-human last common ancestor, eliminating bonobos altogether, sigh) – wasn’t necessarily a clean break, which surely makes sense.
Jacinta: Well, yes, as we’ve read, the split was caused by the relatively sudden creation of the Congo River, but the word ‘relatively’, is, well, relative. So this raises the question of speciation in general. Think of those Galapagos finches that so intrigued Darwin. All about differently-shaped beaks, but it didn’t happen overnight.
Canto: Right, so here’s what a website with the rather all-encompassing title “Science” says about our topic:
Tens of thousands of years ago, modern humans slept around with Neandertals and swapped some genes. Now, it turns out one of our closest living relatives, chimpanzees, also dallied with another species. New research reveals that chimps mixed it up with bonobos at least twice during the 2 million years since these great apes started evolving their own identities. Although it’s not yet clear whether the acquired genes were ultimately beneficial or harmful, the finding strengthens the idea that such cross-species mating played an important role in the evolution of the great apes.
Jacinta: Interestingly this Congo River separation which led to a completely different species was repeated by other separations which led to four sub-species of chimps. Which leads me to wonder – what’s the difference between a new species and a sub-species? Why are bonobos ‘deserving’ of being called a different species?
Canto: Well the Science article has some fascinating further information. This was the work of Christina Hvilsom and colleagues, described as ‘conservation geneticists’. They were using any genetic differences they could find to work out where particular chimps were being caught or hunted. But, since the interbreeding of humans and Neanderthals, proven by DNA, had hit the headlines, Hvilsom wondered about the DNA of chimps. So, using the same methods that uncovered Neanderthal in humans –
she and her colleagues determined that 1% of the central chimpanzee’s genome is bonobo DNA. The genetic analysis indicates that this inbreeding happened during two time periods: 1.5 million years ago bonobo ancestors mixed with the ancestor of the eastern and central chimps. Then, just 200,000 years ago, central chimps got another boost of bonobo genes, the team reports today in Science. In contrast, the western chimp subspecies has no bonobo DNA, the researchers note, suggesting that only those chimps living close to the Congo River entertained bonobo consorts.
Jacinta: What this highlights, more than anything to me, is the importance and excitement of genetic and genomic analyses. Not that we’re experts on the topic, but it has clearly revolutionised the science of evolution, complicating it in quite exciting ways. Think again of those Galapogos finches. Separation, some interbreeding, more separation, less interbreeding, but with a few kinks along the way.
Canto: And we’re just beginning our play with genetics and genomics. There’s surely a lot more to come. Ah, to live forever…
Jacinta: So how did they know some inbreeding occurred? Can we understand the science of this without torturing ourselves?
Canto: David Reich’s book Who we are and how we got here tells the story of interbreeding between human populations, and how population genetics has revolutionised our understanding of the subject. With dread, I’ll try to explain the science behind it. First, the Science article quoted above mentions a split between bonobos and chimps 2 million years ago. Others I’ve noted go back only about a million years – for example a Cambridge University video referenced below. The inference, to me, is that there was a gradual separation over a fair amount of time, as aforementioned. I mean, how long does it take to create a major river? Now, I can’t get hold of the data on chimp-bonobo interbreeding in particular, so I’ll try to describe how geneticists detect interbreeding in general.
I’ll look at the human genome, and I’ll start at the beginning – a very good place to start. This largely comes from Who we are and how we got here, and the following quotes come from that book. The human genome consists of a double chain of 3 billion nucleobases, adenine, cytosine, guanine and thymine. That’s 6 billion bases (often called letters – A, C, G and T) in all. Genes are small sections of this base chain (called DNA), typically a thousand or so letters long. They’re templates or codes for building proteins of many and varied types for doing many different kinds of work, although there are segments in between made up of non-coding DNA.
Researchers have been able to ‘read’ these letters via machinery that creates chemical reactions to specific DNA sequences:
The reactions emit a different colour for each of the letters A, C, G and T, so that the sequence of letters can be scanned into a computer by a camera.
What anthropologists want to focus on are mutations – random errors in the copying process, which tend to occur at a rate of about one in every thousand letters. So, about 3 million differences, or mutations, per genome (3 billion genes, coding or non-coding). But genomes change over time due to these mutations and each individual’s genome is unique. The number of differences between two individuals’ genomes tells us something about their relatedness. The more differences, the less related. And there’s also a more or less constant rate of mutations:
So the density of differences provides a biological stopwatch, a record of how long it has been since key events occurred in the past.
As Reich recounts, it was the analysis of mitochondrial DNA, the tiny proportion of the genome that descends entirely down the maternal line, that became a corner-stone of the out-of-Africa understanding of human origins, which had been competing with the multi-regional hypothesis for decades. ‘Mitochondrial Eve’ – a rather ‘western’ moniker considering that the Adam and Eve myth is only one of a multitude of origin stories – lived in Botswana in Southern Africa about 160,000 to 200,000 years ago, given the variability of the genomic ‘clock’ – the mutation rate.
So, what does this have to do with chimps and bonobos? Well, The exact detail of how Hvilsom et al proved that their (slightly) more recent interbreeding events occurred is hidden behind a paywall, and you could say I’m a cheapskate but the reality is I’m quite poor, trying to bring up seven kids and a few dozen grandkids in a home not much bigger than a toilet, so… but truthfully I’m just getting by, and I just want to know in general the techniques used.
First, they have to find ancient specimens, I think. But, in a video referenced below, they raised the question – Can we ‘excavate’ ancient DNA from modern specimens? We’ve learned that many modern humans have a certain percentage of Neanderthal DNA, say around 2%, but each person’s 2% may be different. Aggregating those different segments can, if we analyse the genomes of enough humans, create a whole Neanderthal genome, though not one of any Neanderthal who ever lived! At least that’s how I’m reading it, in my dilettantish way. So what exactly does this tell us? I’m not at all sure – it’s a relatively new research area, and completely new to me.
The presenter of this video uses the heading, at least at the beginning of his talk, ‘A little Archaic introgression goes a long way’. So now I need to know what introgression means. A quick look-up tells me it’s:
‘the transfer of genetic information from one species to another as a result of hybridization between them and repeated backcrossing‘.
I’ve bolded two key words here. Hybridisation, in mammals, is ‘breeding between two distinct taxonomic units’. Note that the term species isn’t used, presumably because it has long been a questionable or loaded concept – life just seems too complex for such hard and fast divisions. Backcrossing seems self-explanatory. Without looking it up, I’d guess it’s just what we’ve been learning about. Canoodling after speciation should’ve ruled canoodling out.
But, looking it up – not so! It’s apparently not something happening in the real world, something like backsliding. But then… Here’s how Wikipedia puts it:
Backcrossing may be deliberately employed in animals to transfer a desirable trait in an animal of inferior genetic background to an animal of preferable genetic background.
This is unclear, to say the least. How could an animal, even a human, deliberately do this? We could do it to other animals, or try it, based on phenotypes. We’ve been doing that for centuries. What follows makes it more or less clear that this is about human experimentation with other animals, though.
Anyway, I’m going well off-topic here. What I wanted to do is try to understand the proof of, or evidence for, bonobo-chimp interbreeding. I accept that it happened, well after the split between these two very similar-looking species. What could be less surprising? Along the way I’ve been reminded inter alia, of homozygous and heterozygous alleles, but I’ve been frustrated that straightforward information isn’t being made available to the general public, aka myself. I’ll pursue this further in later posts.
Jacinta: What a mess. Phenotype isn’t everything my friend. To a bonobo, a chimp probably looks like a neanderthal – a real bonehead… They probably only had sex with them out of pity. ‘Boys, we’ll show you a good time – like you’ve never had before.’
References
https://www.science.org/content/article/chimps-and-bonobos-had-flings-and-swapped-genes-past
David Reich, Who we are and how we got here, 2018
https://www.newscientist.com/article/2110682-chimps-and-bonobos-interbred-and-exchanged-genes/
the evolution of reason: intellectualist v interactivist
In The Enigma of Reason, cognitive psychologists Hugo Mercier and Dan Sperber ask the question – What is reason for? I won’t go deeply into their own reasoning, I’m more interested in the implications of their conclusions, if correct – which I strongly suspect they are.
They looked at two claims about reason’s development, the intellectualist claim, which I might associate with Aristotelian and symbolic logic, premises and conclusions, and logical fallacies as pointed out by various sceptical podcasts and websites (and this can also be described as an individualist model of reasoning), and the interactionist model, in which reason is most effectively developed collectively.
In effect, the interactionist view is claiming that reason evolved in an interactionist environment. This suggests that it is language-dependent, or that it obviously couldn’t have its full flowering without language. Mercier and Sperber consider the use of reason in two forms – justificatory and argumentative. Justificatory reasoning tends to be lazy and easily satisfied, whereas it is in the realm of argument that reason comes into its own. We can see the flaws in the arguments of others much more readily than we can our own. This accords with the biblical saying about seeing motes in the eyes of others while being blind to the bricks in our own – or something like that. It also accords with our well-attested over-estimation of ourselves, in terms of our looks, our generosity, our physical abilities and so on.
I’m interested in this interactionist view because it also accords with my take on collaboration, participatory democracy and the bonobo way. Bonobos of course don’t have anything like human reason, not having language, but they do work together more collectively than chimps (and chimp-like humans) and show a feeling towards each other which some researchers have described as ‘spiritual’. For me, a better word would be ‘sympathetic’. Seeing the value in others’ arguments helps to take us outside of ourselves and to recognise the contribution others make to our thinking. We may even come to realise how much we rely on others for our personal development, and that we are, for better or worse, part of a larger, enriching whole. A kind of mildly antagonistic but ultimately fulfilling experience.
An important ingredient to the success of interactionist reasoning is the recognition of and respect for difference. That lazy kind of reasoning we engage in when left to ourselves can be exacerbated when our only interactions are with like-minded people. Nowadays we recognise this as a problem with social media and their algorithms. The feelings of solidarity we get with that kind of interaction can of course be very comforting but also stultifying, and they don’t generally lead to clear reasoning. For many, though, the comfort derived from solidarity outweighs the sense of clarity you might, hopefully, get from being made to recognise the flaws in your own arguments. This ghettoisation of reason, like other forms of ghettoisation, is by and large counter-productive. The problem is to prevent this from happening while reducing the ‘culture shock’ that this might entail. Within our own WEIRD (from Western Educated Industrial Rich Democratic countries) culture, where the differences aren’t so vast, being challenged by contrary arguments can be stimulating, even exhilarating. Here’s what the rich pre-industrialist Montaigne had to say on the matter:
The study of books is a languishing and feeble motion that heats not, whereas conversation teaches and exercises at once. If I converse with a strong mind and a rough disputant, he presses upon my flanks, and pricks me right and left; his imaginations stir up mine; jealousy, glory, and contention, stimulate and raise me up to something above myself; and acquiescence is a quality altogether tedious in discourse.
Nevertheless, I’ve met people who claim to hate arguments. They’re presumably not talking about philosophical discourse, but they tend to lump all forms of discord together in a negative basket. Mercier and Sperber, however, present a range of research to show that challenges to individual thinking have an improving effect – which is a good advert for diversity. But even the most basic interactions, for example between mother and child, show this effect. A young child might be asked why she took a toy from her sibling, and answer ‘because I want it’. Her mother will point out that the sibling wants it too, and/or had it first. The impact of this counter-argument may not be immediate, but given normal childhood development, it will be the beginning of the child’s road to developing more effective arguments through social interaction. In such an interactive world, reasons need to much more than purely selfish.
The authors give examples of how the the most celebrated intellects can go astray when insufficiently challenged, from dual Nobel prize-winner Linus Pauling’s overblown claims about vitamin C to Alphonse Bertillon’s ultra-convoluted testimony in favour of Albert Dreyfus’ guilt, to Thomas Jefferson’s absurdly tendentious arguments against emancipation. They also show how the standard fallacious arguments presented in logic classes can be valid under particular circumstances. Perhaps most convincingly they present evidence of how group work in which contentious topics were discussed resulted in improvements in individual essays. Those whose essay-writing was preceded by such group discussion produced more complex arguments for both sides than did those who simply read philosophical texts on the issues.
It might seem strange that a self-professed loner like me should be so drawn to an interactionist view of reason’s development. The fact is, I’ve always seen my ‘lonerdom’ as a failing, which I’ve never tried very hard to rectify. Instead, I’ve compensated by interacting with books and, more recently, podcasts, websites and videos. They’re my ‘people’, correcting and modifying my own views thorough presenting new information and perspectives (and yes, I do sometimes argue and discuss with flesh-and-blood entities). I’ve long argued that we’re the most socially constructed mammals on the planet, but Mercier and Sperber have introduced me to a new word – hypersocial – which packs more punch. This hypersocial quality of humans has undoubtedly made us, for better or worse, the dominant species on the planet. Other species can’t present us with their viewpoints, but we can at least learn from the co-operative behaviours of bonobos, cetaceans, elephants and corvids, to name a few. That’s interaction of a sort. And increased travel and globalisation of communications means we can learn about other cultures and how they manage their environments and how they have coped, or not, with the encroachments of the dominant WEIRD culture.
When I say ‘we’ I mean we, as individuals. The authors of The enigma of reason reject the idea of reason as a ‘group-level adaptation’. The benefits of interactive reason accrue to the individual, and of course this can be passed on to other receptive individuals, but the level of receptivity varies enormously. Myside bias, the default position from our solipsistic childhood, has the useful evolutionary function of self-promotion, even survival, against the world, but our hypersocial human world requires effective interaction. That’s how Australian Aboriginal culture managed to thrive in a set of sub-optimal environments for tens of thousands of years before the WEIRDs arrived, and that’s how WEIRDs have managed to transform those environments, creating a host of problems along with solutions, in a story that continues….
Reference
H Mercier & D Sperber, The enigma of reason, 2017
21 – dolphins, bonobos, sex and pleasure
bonobos at Jacksonville zoo
I enjoyed a little boat trip off the north-east coast of Kangaroo Island recently. The owner, our guide, bounced us up and down the shoreline east of Christmas Cove to view caves in the limestone cliffs, seabirds such as wedge-tailed eagles on the cliff-tops, and above all to search for a pod of dolphins known to be using the area as a daytime resting-place.
After a few bouts of bouncing eastward and westward we were becoming skeptical, though by no means annoyed. A year before, the island, Australia’s third largest after Tasmania and Melville Island, had been ravaged by bushfires, devastating vegetation and wildlife, and seriously damaging the island’s fragile economy, not to say ecology, and we were happy to make our tiny contribution without great expectations of sighting fabulous beasties.
So we were delighted, on heading eastward again, to spot a few fins bobbing and dipping in the water ahead. Slowing toward them, we were told there were about 25 dolphins in this pod (the term was first used by whalers in the early nineteenth century, for reasons unknown). I soon gave up trying to count them as identical-looking fins appeared and disappeared and vaguely discerned bodies twisted and turned just below the surface. They seemed to form pairs now and then, breaking the surface sleekly and synchronously in elegant arcs. Dolphins, I learned, spend their days lolling about near the shore in these pods after a night of hunting out at sea. They seemed aware but unconcerned about our presence, and at one time the whole group disappeared then reappeared on the other side of our boat, bobbing and slow-twirling as before.
I was struck by a remark by our guide that dolphins are one of the few mammals that mate for fun or pleasure. Of course I made an immediate connection with bonobos, but then I wondered, what does the verb, to mate, exactly mean? We humans never describe ourselves as mating, that’s for the birds, etc. We fuck, screw, bonk, shag, hump and bone, we more coyly sleep together, and more romantically make love (not allowed for other species), but we’re way above mating.
‘Mating’ brings up two internet definitions, the action of animals coming together to breed, and copulation. So dolphins, and bonobos and humans, often come together to breed – but actually not to breed. As for copulation, that’s rarely used for humans, just as fornication is rarely used for non-humans. The latter is, of course, a term of mostly religious disapproval, and non-humans are too lowly to be worthy of moral judgment.
Of course we do apply mating to humans with a pinch of irony, as in the mating game, and this blurs the line between humans and others, but not enough for me. The point is that dolphins and bonobos use sex, which may not be the full rumpy-pumpy (dolphins don’t even have rumps to speak of), to bond with each other, to ease tension, to have fun, as our guide said. But then, don’t all species have sex purely for pleasure, or at least because driven to do so, by sensation? Do cats, dogs, birds and flies have sex with the intention of reproducing? I don’t think so.
Human sex is pleasurable, so I’ve heard, and I expect bonobo sex is too. Fly sex probably not, or so I thought, but I’m probably wrong. Researchers have found that male fruit flies enjoy ejaculating, and tend to consume alcohol when denied sex. I know exactly how they feel. Anyway, fruit flies have long been favourites for biological research, and more recently they’ve found that ‘a protein present in the ejaculate of male fruit flies activates long-term memory formation in the brains of their female partners’. It rather makes me wonder what effect this kind of research has on the researchers themselves, but I’m sure it’s all for the best.
One thing is certain, cats and dogs, and I’ve had a few, feel pleasure. Cats are appallingly sensual, and I’ve probably had more sexual advances from dogs than from humans, though whether they involved pleasure I can’t be sure. Generally our understanding of non-human sex has expanded in recent decades, as our sense of our specialness in everything has receded. It’s also true that we’ve tended to look at other species with a scientific instrumentalism, that’s to say from the viewpoint of evolution, breeding, genetics and other forms of categorisation, rather from an emotional or sensory viewpoint.
When I was very young I read a book by Ernest Thompson Seton called The biography of a grizzly. This story of Wahb, a male grizzly whose family was wiped out by hunters, and who survived to become the most powerful bear in the region, before inevitable decline and death, had an unforgettable emotional impact. I’m glad I read it though, as, sentimentalised though it might’ve been, it inoculated me against the scientific tendency, now changing, to see any animal as an it, rather than he or she or dad or mum or brother or sister. So this idea of putting oneself in the paws of a grizzly or the feet of a bonobo has long been perfectly legitimate to me.
In 2014 Jason Goldman wrote an article entitled Do animals have sex for pleasure?, in which he cited many instances of other species – bonobos of course heading the list – engaging in oral and penetrative sex ‘out of season’, when pregnancy is precluded. They include capuchin monkeys, macaques, spotted hyenas, bears, lions and fruit bats. It stands to reason that the physiological, whole-of body pleasure we derive from sex is shared by other species, and is indulged by them, and this includes what we call homosex, and masturbation. Australia’s premier science magazine, Cosmos, claimed a few years ago that some 6000 species (or was it 600?) have been observed engaging in homosexual activity, which does sound funny when talking about what we would habitually call lower life forms.
All of these findings have had the effect, and perhaps the intention, of loosening our uptight attitudes toward sex, as well as upending our notions of human specialness. But the behaviour of bonobos, who at times look strikingly like us, is more immediately impactful than anything fruit flies or fruit bats might do. Just the other day I watched a video of bonobos in Jacksonville zoo, Florida. Two of them were lying on the ground close together, and kissing each other, on the lips, again and again. Were they male? female? one of each? Who knows, it was so beautiful to watch.
References
Ernest Thompson Seton, The biography of a grizzly, 1900.
https://www.the-scientist.com/news-opinion/male-fruit-flies-take-pleasure-in-having-sex-30867
https://www.the-scientist.com/news-opinion/sex-promotes-lasting-memories-in-female-flies-66763
Bonobos at Jacksonville Zoo (video)
stuff on human ancestry 1: the australopithecines, mostly
All the evolution we know of proceeds from the vague to the definite
C S Pierce
I was in a bookshop yesterday, where I picked up a copy of Yuval Noah Harari’s book Sapiens and had a gander at the back cover. I read one sentence, which went something like ‘100,000 years ago there were at least six species of Homo sapiens, now there is only one.’ Or maybe it was just ‘six species of Homo‘. It resonated with me, because it’s been a while since I’ve researched and written about the ever-fascinating topic of human origins, a topic that resurfaced for me recently on reading an essay, ‘Lucy on the earth in stasis’ by Stephen Jay Gould in his 1996 collection Dinosaur in a haystack. The essay promoted his ‘punctuated equilibrium’ view of evolution, as it reported that Australopithecus afarensis appeared to be the only hominin type in existence for a period of almost a million years, from approximately 4.9 million years ago to 4 million years ago, after which there was a relatively rapid radiation of hominid species. I could only take the essay on trust, but I maintained the thought that I should investigate whether this claim still held, some twenty-three years later. And that, further, I should investigate whether we were any clearer about our descent, as the last surviving species of that apparent radiation.
And by the way, for my education’s sake I need to straighten out the difference between hominids and hominins. We humans are both, apparently. The hominids, or great apes, include four genera: Pongo, the orang-utangs, of which there are three extant species; Pan, of which there are two species, chimps and bonobos; Gorilla (two species), and Homo, of which there’s only one extant species, but many extinct ones including Neanderthals. The term ‘hominid’ has broadened over time. The term ‘hominin’ is more restrictive, referring only to those species ancestral or related to humans, since the split from the chimp and bonobo line. This explains, I hope, why we are both hominids and hominins. Clearly, though, I should stick to the term hominin for this post, or series of posts.
Anyway, I was surprised to read this claim about the state of human play 100,000 years ago. The old Bill Bryson question, How do they know that? came to mind, but I also felt skeptical, as I seemed to remember that the number was smaller – possibly dependent on whether you were a lumper or a splitter.
We know of course that our closest living relatives are (equally) chimps and bonobos, and the latest dating of our divergence from their line is 4 to 7 million years (according to Wikipedia, but Gould put it at 6 to 8 mya, and this video from the American Museum of Natural History gives it more ‘precisely’ at 7 mya, and another Wikipedia article gives the figure as 6.5 to 5.5 mya, so who knows?) There are a couple of possibilities for our last shared ancestor – Sahelanthropus tchadensis and Orrorin tugenensis – but their more or less competing claims are mired in uncertainty, due to the extreme sparsity of material. It may well be that neither of them fit the bill.
When they look at the evidence from early hominins, researchers are particularly interested in signs of bipedalism, which have been argued to exist in S tchadensis due to the placement of its foramen magnum (the hole in the skull through which the spinal cord passes) towards the back – though this placement has been disputed, quelle surprise. In any case, these earliest hominins evolved during the Pleiocene epoch into the definitely bipedal australopithecines. The bipedal adaptation is so important to the emergence of Homo sapiens that it has been the subject of a great deal of speculation, hypothesis and argumentation. It’s likely that there were a variety of converging factors that favoured this trait’s development. For example, it provided a wider visual field, especially on the ground; it left the hands free to grasp and carry food; it enabled long-distance running, and it reduced the expenditure of energy. However, bipedalism appears to have been a slow development, and early australopithecines such as A afarensis likely spent a lot of time in trees. This is supported by anatomical features such as longer arm-bones, curved fingers, a shallow rib-cage and strong clavicular anchors for brachiation (swinging from the arms among branches).
Over time there were anatomical changes favouring bipedality. These included greater robustness of the ankle and knee joints, and changed positioning of the foramen magnum, the femur and the spine, to support changes to the centre of gravity. But the changes which have had the most long-lasting, even at times dire effects, have been those to the pelvic region. The strengthening and widening of this region, including the ilium, ischium and pubis, to support an upright stance, has to a serious degree compromised the process of childbirth. It’s been observed that australopithecines share with modern humans a sexual dimorphism relating to the lumbar vertebrae, allowing the spinal curvature of females to become more pronounced during pregnancy, which helps to better distribute the weight of the unborn child and to reduce fatigue and maintain stability of posture for the mother. However, the changed shape of the pelvis and the consequent narrowing of the birth canal resulted in what has become known as ‘the obstetrical dilemma’. Unlike virtually every other mammalian species, humans face major difficulties and dangers in childbirth, which require others – midwives or other medical professionals – to assist in the process (for example, neonatal rotation is often necessary for safe delivery). A ‘solution’ to this dilemma, which appears to have evolved over time, is a comparatively short gestation period – the time spent in the womb – to give a greater opportunity for both mother and child to survive the birth. This of course leads to a longer period of childhood dependence as it develops outside the womb. Apparently, a modern human baby is born with approximately 25% of full brain development, compared to 45-50% in other primates. Brain size at birth is limited due to the obstetric dilemma, and greater neoteny is the result.
Encephalisation, which refers to a growth in brain size or mass relative to body size, is now seen as a later development in the human story than bipedalism. Brain size in general has become very questionable as a measure of complex evolutionary development – witness those smart corvids – and it’s worth noting that the Neanderthal brain is on average larger than ours. What’s important, though, is brain structure – something we can’t really look at vis-a-vis our ancestors. However it is reasonable to assume that our much larger brain size compared to australopithecines is largely due to growth in the temporal lobes and the prefrontal cortex. In fact all regions have grown, including the cerebellum, traditionally associated with fine motor control and balance, but more recently connected with cognitive function and language.
But let me return to the hunt for the hominin links from the other great apes to Homo sapiens. In the mid-nineties, two new examples of early hominins were discovered, Australopithicus anamensis and Ardipithecus ramidus. I’m guessing that Gould didn’t know about these discoveries when he wrote his essay, as they seem to have punctured his punctuated equilibrium thesis, at least as regards hominins. Anyway the A anamensis species is believed to have lived from about 4.2 to 3.8 million years ago, and the A ramidus specimens have been dated to around 4.4 million years ago, but interestingly, A afarensis, the principal subject of Gould’s essay, is now believed to have lived from 3.9 million years ago to 2.9 million years ago – that’s a million years after Gould’s stated range. The australopithecines first came to our attention in 1925 when Raymond Dart described Australopithecus africanus from specimens found in South Africa. A africanus is a more gracile type, and may well be in the direct line to humans, though there’s been a lot of dispute about the dating and classifying of different specimens. A africanus is generally thought to be a more recent species than A afarensis, another gracile type. So maybe we can link A africanus back to A afarensis, which in turn can be linked back to S tchadensis, with some intermediate missing links. But then there’s another recently discovered species, Australopithecus sediba, which has been dated to around 2 million years ago and is thought to be a transitional species between A africanus and either Homo habilis (which some prefer to describe as Australopithecus habilis) or Homo erectus. Another gracile species discovered in the nineties, A garhi, dating to about 2.5 million years ago, also seems to fit as a species connecting Australopithecus and Homo. From what I’m reading, the fragmentary nature of these finds, together with obvious questions as to whether particular specimens are typical of whole species (type specimens are often juveniles, which might not be such a good idea), are the main barriers to pinning down the precise lines of succession. That’s why every new discovery is such a treasure.
I haven’t mentioned Ardipithecus or Paranthropus as yet. In the nineties specimens were found in the Afar triangle in East Africa, and classified as Ardipithecus ramidus (around 4.4 million years ago, with uncertain evidence of bipedality, and some evidence of reduced sexual dimorphism) and Ardipithecus kadabba (about 5.6 mya, possibly an ancestor of A ramidus, but known from only a few teeth and bones – the type specimen being a bit of mandible with an attached molar). It’s possible, according to some researchers, that Ardipithecus, Orrorin, and Sahelanthropus all belong to the same genus.
I’ll have a look at Paranthropus, apparently a more robust distant cousin of ours, then move forward to the Homo genus, next time.
References
Australopithecus Evolution (video), by Henry the PaleoGuy, 2019
Seven million years of human evolution (video), American Museum of Natural History, 2018
https://en.wikipedia.org/wiki/Human_evolution
https://en.wikipedia.org/wiki/Australopithecus
https://en.wikipedia.org/wiki/Australopithecus_afarensis
https://en.wikipedia.org/wiki/Australopithecus_africanus
https://en.wikipedia.org/wiki/Australopithecus_sediba
https://en.wikipedia.org/wiki/Australopithecus_anamensis
https://en.wikipedia.org/wiki/Ardipithecus
http://humanorigins.si.edu/evidence/human-fossils/species/ardipithecus-ramidus
a few thoughts on libertarianism
Libertarianism is like Leninism: a fascinating, internally consistent political theory with some good underlying points that, regrettably, makes prescriptions about how to run human society that can only work if we replace real messy human beings with frictionless spherical humanoids of uniform density (because it relies on simplifying assumptions about human behavior which are unfortunately wrong). I don’t know who wrote this.
Aren’t libertarians a lovely lot?
I might look more closely at some libertarian philosophy later, but for now I want to critique the kind of standard libertarianism I’ve heard from politicians and bloggers.
Well, okay, I’ll start with a philosopher, Robert Nozick, whose much-vaunted/pilloried book Anarchy, State and Utopia I tried to read in the eighties. I found it pretty indigestible and essentially learned from others that his argument depended rather too much on one principle – the human right of individuals to certain positive and negative freedoms, but especially negative ones, like the right to be left largely alone, to make their own decisions for example about how to contribute to the greater good. The book ended up advocating for a minimalist state, in which everyone gets to create their own communities of kindred spirits, organically grown A cornucopia of utopias. The kind of state that, ummm, like, doesn’t exist anywhere. That’s the problem. Utopia is definable as a society that only exists in fantasy.
And then there’s the exaltation of the individual. This is the problem I’ve encountered with every libertarian I’ve read or viewed – and I’m quite glad I’ve rarely had any personal encounters with them.
If I did, here would be my response. Homo sapiens are the most socially constructed mammals on the planet. Language has massively facilitated this, and in turn has become our most powerful social product. Common languages have created civilisations, and this has allowed us to dominate the planet, for better or worse. And civilisation requires, or just is, organised social structure. That’s to say, a state, that eternal bogey-man of the libertarian.
This entity, the state, has shaped humans for millennia. Today, we owe (largely) to the state the clothes we wear, the food we eat, the education we’re hopefully still having, the jobs we’ve had and lost, the houses we live in, the cars we used to drive, and the good health we increasingly enjoy. That’s why, it seems to me, we owe it to ourselves to make the state we live in as good as we can make it, in terms of health, safety, opportunity, support, pleasure and self-improvement, for all its members.
It seems to me we have to work with what exists instead of trying to invent utopias – because, obviously, one person’s utopia is another’s nightmare. What exists today is a variety of states, some clearly better than others. The minimalist states are among the worst, and they’re understandably called failed states. There is no effectively functioning minimalist state on the planet, a fact that many libertarians blithely ignore. Their emphasis on individual liberty seems to me the product of either beggar-thy-neighbour selfishness or starry-eyed optimism about natural affinities.
Again, I turn to the USA, my favourite whipping-state. This hotbed of libertarians has not blossomed as it could, considering its booming economy. From this distance, it seems a sad and often stomach-turning mixture of white-collar fraudsters and chronically disadvantaged, over-incarcerated victims, and good people who largely accept this as the status quo. The you-can-achieve-anything mantra of the American Dream generally sees individuals as blank slates who can best fulfil their potential when pulled from the rubble of the coercive state. Or State, as many libertarians prefer.
It didn’t take my recent reading of Robert Sapolsky’s Behave, a superb overview of human behaviour and its multifarious and interactive underpinnings, or Steven Pinker’s earlier The Blank Slate, to realise that this was a dangerous myth. It was always screamingly obvious to me, from my observation of the working-class milieu of my childhood, the variety of skills my classmates displayed and the problems they faced from the outset, together with my readings of more privileged worthies and their patrician connections (Bertrand Russell on the knee of William Gladstone always comes irritatingly to mind), that there has never been anything like an even playing field for exhibiting and making the most of whatever qualities we’re gifted with or are motivated to cultivate and improve.
So this is the problem: we’re not free to undo what has been ‘done to us’ – the parents we have, the country (or century) we’re born in, the traumas and joys we’ve experienced in the womb, our complex genetic inheritance and so forth. All of these things are connected to a much wider world and a past over which we have no control. They shape us (into go-getting libertarians or bleeding-heart liberals or whatever) much more than we’re generally prepared to admit. And these shaping forces, since the emergence of civilisation and that sometimes messily organised unit called the state, are profoundly social. And even if we’re not talking about western civilisation it’s the same – it takes a village to raise a child.
These shaping forces aren’t necessarily bad or good, they just are. But all in all we should be glad they are. The social brain is the brightest, most complex brain, and such brains wouldn’t have developed if the individual was sacrosanct, in receipt of the right to be ‘left alone’. Civilisation is surely the most impressive achievement of human evolution, and as Ralph Adolphs of Caltech puts it, ‘no component of our civilization would be possible without large-scale collective behavior’.
The state, of course, has its drawbacks, as do all large-scale multifaceted administrative entities. The ancient Greek city-states produced a host of brilliant contributors to their own esteem as well as to the world history of drama, philosophy, mathematics and history itself, in spite of being built on slavery and denying any equitable role to women, but even there the (probably few) slaves who worked in the most enlightened households would’ve benefitted from the collective, and the women, however officially treated, were surely just as involved and brainy as the men.
As society has grown increasingly complex we as individuals have grown in proportion, as have our individual delusions of grandeur. At least in some cases. What the best of us should have learned, though, is that a rich, diverse, dynamic society, which cannot but be organised, produces the best offerings to its children. Diminishing the state by refusing to contribute to it actually diminishes and impoverishes the self, diminishes connection and the recognition of collective value. This raises the rather large point that the self isn’t what most people think it is – an autonomous, self-actuated entity. Instead, it is driven by complex social inputs from the very start, indeed from long before it came into being. Just as events from long before a crow is born, or even conceived, will go a long way in determining how that adult crow behaves.
Yet the myth of the individual, autonomous self is a live one, and it’s what drives most libertarians. In so far as people see themselves as self-actualising, they will argue the same for others, and absolve themselves from responsibility for others’ failures, mistakes or incapacities. Such attitudes significantly play down disadvantages of background, and even reduce exposure to those differences. Since everyone has the choice to be as successful as me (according to my own measure of success), why should I waste time hanging out with losers? By that measure, to suggest that silver-spoon libertarians would willingly provide support to disadvantaged communities is as unrealistic as expecting Donald Trump to hang out with the construction workers on his trumpy towers.
In some respects, libertarianism represents the opposite pole to communism, on a continuum that stretches into complete delusion at both ends. There have never been any actual, functioning communist or libertarian states. Both are essentially abstract ideologies, which take little account of the science of evolved human behaviour. When we do take account of that science, we find it is fiendishly complex, with the individual as a unit being driven and shaped by social dependencies, connections and responsibilities, which are generally vital to that individual’s well-being. In western democratic societies, apart from family and workplace organisations, we have government, which includes, in Australia, councils, states and a federation of states. It all sound terribly complex and web-like, and some apparently see it as ‘the enemy of individual liberty’ but in fact it’s the web of civilised human life, which we’ve all contributed to creating, and it’s a pretty impressive web – though more impressive in some places than in others. I think the best thing we can try to do is to improve it rather than trying to extricate ourselves from it. In any case, doing so – I mean, removing ourselves from organised society – just won’t work, and fundamentally misunderstands the nature of our evolved humanity.