Posts Tagged ‘bonobos’
Beauvoir, Stendhal, bonobos and the past
Canto: So, having read The Second Sex recently, I’m pondering over her essay on Stendhal, a writer I was a little obsessed with in the 1980s, in the years of my fading youth…
Jacinta: Right, so near the middle of that book Beauvoir wrote five little essays on five writers, treating of their treatment of women, from the most misogynist to – Stendhal. So the first four, in order, were Henry de Montherlant, D H Lawrence, Paul Claudel and Andre Breton.
Canto: Yes and she mentions Stendhal with affection in Memoirs of a dutiful daughter too, so it transports me back to my discovery of Stendhal’s work in the early eighties, and then, in the late eighties, my decision to write my French Honours thesis on Stendhal’s work, which led me to read and reread more or less all of his oeuvre, as well as much literary criticism, including, if I’m not much mistaken, Beauvoir’s essay.
Jacinta: And in that essay, she points out that Stendhal is more invested in the female characters than the males. His writing career is bookended by Lamiel, his unfinished last novel, and Armance, his first written work of fiction, which uses physical impotence effectively to disguise the emotional difficulties faced by the male lover, Octave…
Canto: Well I’ve been reading critiques, by women, of Beauvoir’s treatment of Stendhal’s treatment of women, and it all becomes a bit abstruse, but surely nobody wold doubt that Stendhal has a view of women that is very much out of synch with his time. But what most interests me, is the personal nature of his interest. Because I identify with it. I very much recall his account, in Vie de Henri Brulard, of his writing the names in sand, or was it dirt, of the women he loved (whatever that may mean), and who never returned his feelings. And watching the waves, or was it the wind, wash those names away. Stendhal was always a ‘brevity is the soul of wit’ writer, whose writing became most taut when emotionally charged. Few writers have had greater emotional impact on me than Stendhal, no doubt because I too have been a terrible failure in love, or lust, or whatever it is that brings bodily closeness, of the kind that bonobos manage so effortlessly.
Jacinta: Culture, and religion, and its aftermath, have left us with a legacy that makes physicality, so basic to other mammals, an arena replete with problems. The very process of writing illustrates this. Bonobos don’t write, or talk, they don’t put off spontaneity. If they’re spurned, as Stendhal was spurned by those he obsessed over, they find someone else, without giving up on their first choice. And if they’ve proved themselves, they might succeed in their first choice next time, without giving up on their second choice…
Canto: But maybe there’re bonobo versions of Stendhal, and myself, who don’t succeed in their first second or third choices…
Jacinta: Bonobo society is clearly inclusive. It’s not just about sex, but about closeness. That’s what makes for less violence and more collaboration. In the primate world, our world, greater female empowerment makes all the difference.
Canto: No bonobo left behind. But we have become ‘literate’, spectacularly, which has led to our science and complexity, Shakespeare and Newton and music and quantum mechanics and longevity and so many understandings of the universe and neutrinos and the butterfly effect and complex feedback loops…
Jacinta: And still there is warfare – involving the rape and murder of women – a feature of every example of warfare over the last 5000 years and more – and invariably perpetrated by men. Men men men men men men men.
Canto: What about Thatcher and the Falklands?
Jacinta: Complex, but initiated by the aggression of Argentinian males, and of course there are aggressive women…
Canto: Well getting back to Stendhal and Beauvoir, let me offer this quote from Beauvoir’s essay for our commentary:
Music, painting, architecture, everything he cherished, he cherished it with an unlucky lovers’ soul; while he is walking around Rome, a woman emerges at every turn… by the regrets, desires, sadnesses and joys women awaken in him, he came to know the nature of his own heart; it is women he wants as judges: he frequents their salons, he wants to shine; he owes them his greatest joys, his greatest pain, they were his main occupation; he prefers their love to any friendship, their friendship to that of men; women inspire his books, women figures populate them; he writes in great part for them. ‘I might be lucky enough to be read in 1900 by the souls I love, the Mme Rolands, the Melanie Guilberts…’ They were the very substance of his life.
Simone de Beauvoir, The Second Sex (Vintage Books, p261)
Jacinta: Sad. Mais touchant, tout de même. It seems like it’s both a joy and a torture. Joy in remembrance and contemplation, but suffering in the presence of their indifference, or disdain, or discomfort. And that’s how you feel? But then you have me. But of course you am I. Am you. Am I?
Canto: Haha, well it’s more like how I used to feel, before I became a dried out old husk. I could tell some comically sad tales of my youth, but now I think of these things in a more abstract way. And admiring the example of bonobos as the human way of the future is about as abstract as it gets, so I feel very comfortable about it. And I talk to myself a lot, but I’m not even sure any more if my imagined interlocutor is female.
Jacinta: Ah, the way we were. So, all passion spent, you can focus on more important things like war and peace, global warming, artificial intelligence, female empowerment, wealth inequality, the WEIRDening of the world…
Canto: And, of course, bonobos. I really would like to be one. Just for one day.
References
Simone de Beauvoir, The second sex, 1949
Simone de Beauvoir, Memoirs of a dutiful daughter, 1958
Stendhal, Vie de Henry Brulard, 1890
Stendhal, Love, 1822
sex and gender in bonobos, humans, etc
So there’s been a lot of talk lately about trans people, whatever that may mean, and whether or not they should be taken seriously. It seems to relate to the ‘woke’ issue, for some people, and it has become a hot button issue for the most divided and tedious nation in the WEIRD world. All of this has to do with sex and gender, it seems to me, and I’ve had many thoughts on this topic ever since I was a kid, over fifty years ago.
I’ve written about this before, briefly, but I want to go into it in more detail now. I was around eleven or so, pre-pubescent, in primary school, year 5 or 6. It was school assembly, and we were standing in line outside the school buildings, listening to some headmasterly homilies. I was at the back of the two lines for our class, one for girls, one for boys. It was probably towards the end of the year, because I was very familiar with my classmates, at least by observation. As I looked at them this day, I considered which ones were the most, and least, attractive, and why. I knew nothing about sex at the time (unlike most eleven-year-olds today), but I knew about physical attraction – and attraction generally. My thoughts ran along lines which I still feel proud of to this day, though no doubt I’ll exaggerate their sophistication, as is the way with memories.
I decided that the prettiest kid in the class was a boy, and I was ‘turned on’ by the naughtiness of this thought. I also noted that of the two prettiest girls, one was much more attractive to me than the other, not because of her physical appearance, but her manner – perhaps her air of gravity, her intelligent expression, the clothes she wore, her way of walking. And then there were girls I was attracted to, but not physically. They were fun, good sports, approachable. And on further reflection I noticed that the kids who least interested me were the ‘girlie’ girls and the ‘tough guy’ boys, and that the kids in front of me could all be put on a spectrum from most masculine to most feminine, regardless of their actual genitalia. Which led me to wonder – where was I on this spectrum?
It so happens that throughout my school years I was the shortest kid in my class, male or female, and skinny with it. A less masculine male could hardly be imagined. I never considered myself homosexual though. By the time I fully understood the term, the blokes my age were developing face fuzz, which was a total turn off. That didn’t stop me from falling in love with Bowie at sixteen – the music, that is, and the in-your-face androgynous persona. This tended to make me persona non grata in the socially conservative working-class environment of my childhood and early youth.
All of this is to say that I was highly sensitised to issues of sex and gender from an early age. Some years later, well into my twenties, a certain family kerfuffle came to my attention. A married cousin had a daughter, aged about six or so, who insisted on keeping her hair short and refused to be dressed in a dress. I encountered her once or twice, and she seemed morose, withdrawn, smart, and yes, kind of masculine, if that makes sense for someone so young. My mother seemed worried, as did other family members, but the mother not so much. There was talk of doctors, of taking a firmer line, and I didn’t know what to make of it. Nobody asked my advice of course, but I would’ve argued for letting the girl, or boy, be what they wanted to be. I was thoroughly fascinated, however. But I soon lost touch with family, became as solitary as an orang-utan, and know nothing of the outcome.
Returning to modern times, people talk today of the LGBTQIA+ community, and I can probably work out what each letter signifies, but only just. It seems to me that if there is a problem here, it’s a problem of categorising and compartmentalising – maybe of working out which ‘tribe’ you supposedly belong to. I myself have never been particularly tribal, so it all just flies over my head. And anyway, is there a community here, a community of difference? I hope so, but I’m doubtful.
I’ve mentioned orang-utans, but it’s the far from solitary bonobos I’m really interested in. Opposites attract, they say. Recently I’ve been pondering sex and gender in our primate cousins, and other mammals. Does our pet dog know she’s a girl? Does our pet cat know he’s a boy? We call our pets such things to eternally infantilise them, but that’s another story. Let’s consider bonobos – when, if ever, do they learn that they’re male or female? And when do we humans learn the same? For humans, it seems straightforward – we have language. One of the first things a child learns is that they’re ‘a pretty/naughty/clever girl, or boy, as the case may be. This sort of makes up for the fact that we rarely get to go about naked and notice the difference in each others’ genitalia – unlike bonobos. But our bonobo and chimp cousins are smart and complex – they know the difference between the one who nurses and protects them and the adults who are sometimes friendly but at other times indifferent or hostile. They might not conceive it in terms of gender, but they might discern a pattern. And of course hormonal and developmental differences both between and within the two sexes will play their part. So they too have ‘gender issues’, if we can call it that.
It’s often said that sex is biological, gender is cultural. That, of course, is way too neat, and too hard to prove, because every single family in which a child is brought up is a micro-culture of sorts, and every child has a slightly different genetic and epigenetic inheritance. The problem again is our tendency to compartmentalise. What is more important, as bonobos might teach us, is acceptance of variety and difference.
Another obvious difference between bonobos and the only clothed apes, is of course, clothing, covering, hiding our ‘naughty bits’. It’s a topic I tend to be squeamish about, being human, but it needs to be addressed. We wear clothing for a whole variety of reasons – for keeping protected and warm, to display solidarity with our tribe, to be fashionable and attractive, to show contempt for fashionable elites, to avoid being arrested for indecent exposure, and so on. We certainly learn from very early on that it’s ‘rude’ and ‘uncivilised’ to go about in the altogether. It’s interesting to note that the term ‘savage’, used regularly by Europeans well into the 19th century, precisely coincided with the degree of covering used by the indigenous populations they encountered. The more covered they became, the more civilised and intelligent they became in our minds.
It’s also worth noting that, until recently in the WEIRD world, clothing and other visible accoutrements have been used to distinguish the two sexes – hence the concept of cross-dressing, which now seems dated. In my own youth my hair was long and bushy, and it seemed to me that most of the girls’ hair was shorter than the boys’, which I found titillating. At the time I thought it was revolutionary, and went along with free love and the dissolution of marriage, but sadly it turned out to be just another turn of the fashion wheel.
And yet, not quite. Or not at all. Some of us might be slaves to fashion, but the percentage has considerably reduced. Gone forever are the days, revealed in 100 year-old photos and newsreels, when men were obliged to wear more or less lookalike homburgs, and women cloche hats. Jeans, t-shirts and casual jackets are as commonplace now as they were fifty years ago, and casual apparel has maintained its non-binary style in that time. Fashions may go in cycles but they never return to the same place. Marriage is still popular, but it’s not what it was when my dad were a lad.
So at a time when sexual identity and politics are being fought over to a degree that I find laughable, it’s a relief to turn to the bonobo world. Bonobos females tend to engage in same sex acts a lot more than males do, according to research by the Max Planck Society, and this activity creates more lifelong bonds than occurs with mixed-sex pairs. The research suggests that this has to do with increased oxytocin levels after these interactions. Oxytocin, the so-called ‘feel good’ or ‘love’ hormone is often associated with the bonding of mother and child. These increased levels didn’t occur after male-female sex. Interestingly, and very surprisingly (and rather disappointingly to me) male-male sex is rare among bonobos. Considering that some 75% of bonobo sex has no reproductive purpose (compared to 99.999% of human sex, according to my own extensive research), this seems to me a missed opportunity. Then again, this female-female bonding appears to be the key, not only to female dominance, but more importantly that species’ lack of aggression compared to chimps and humans. Obviously the answer for us humans is to ban male homosexuality on penalty of death, and encourage the female version with prizes and worldwide fame for the loudest and longest orgasms.
Okay, I was a bit drunk when I wrote that.
There’s a lot more to be said, though, about how bonobos have broken the aggression habit, or how they’ve targeted aggression to reduce aggression, and so to become less aggressive overall. I’ll explore that in my next post.
https://phys.org/news/2019-09-insights-same-sex-sexual-interactions-important.html
why do fools fall in love, and bonobos not so much?
Animals don’t ‘fall in love’, right? Only humans do that sort of thing. But wait on – humans are animals. Darwin told me so. Funny how we keep forgetting that. Or, if we’re members of particular religions, we insist it just isn’t so. Simone de Beauvoir, in a section near the end of her monumental work The Second Sex, titled ‘The woman in love’, describes this rather mythologised experience from the second sex’s perspective:
The supreme aim of human love, like mystical love, is identification with the loved one. The measure of values and the truth of the world are in his own consciousness; that is why serving him is still not enough. The woman tries to see with his eyes; she reads the books he reads, prefers the paintings and music he prefers, she is only interested in the landscapes she sees with him, in the ideas that come from him; she adopts his friends, his enemies and his opinions; when she questions herself, she endeavours to hear the answers he gives; she wants the air he has already breathed in her lungs; the fruit and flowers she has not received from his hands have neither fragrance nor taste; even her hodological space is upset: the centre of the world is no longer where she is but where the beloved is; all roads leave from and lead to his house. She uses his words, she repeats his gestures, adopts his manias and tics. ‘I am Heathcliff,’ says Catherine in Wuthering Heights; this is the cry of all women in love; she is another incarnation of the beloved, his reflection, his double: she is he. She lets her own world founder in contingence: she lives in his universe.
I can hear plenty of women I know roaring with laughter at this description. It might seem dated and extreme, but Beauvoir directly quotes women of her time and earlier who give expression to this type of mindset, and a whole sub-genre of romantic literature is still devoted to it. And after all, humans are essentially monogamous, unlike any of the other great apes.
But how essential is our monogamy, really?
Bonobos have been lightly referred to as the ‘make love not war’ apes, or our ‘hippy’ cousins. These are telling references, methinks. I have to say that when I was a young teen, and sometimes shell-shocked witness to a very unhappy parental marriage, I had high hopes that the hippy ‘love the one you’re with’ lifestyle (and revolution) was here to stay, and that marriage, the consecration of monogamy, was on its way out. I won’t say those hopes were entirely dashed, because over the past fifty years or so, with the introduction of no-fault divorce, the greater acceptance of same sex relations and non-marital partnerships, and the drop in religious belief, traditional marriage has certainly been tottering on its pedestal. But there are other barriers to our adopting a bonobo lifestyle of all-in, apparently indiscriminate frottage and sexual healing – including our ideas about ‘true love’.
One factor, surely, has ensured the continued supremacy of monogamy in our society – the production and maintenance of offspring. While it’s generally conservatives who maintain that ideally children need a father and a mother for a ‘balanced’ upbringing (in spite of many examples to the contrary), the idea, I’ve found, niggles at many a single parent I’ve encountered. My own mother – by far the dominant parent, the breadwinner, the rule-maker, the sometimes unnerving dictator – seemed obsessed that the weakness of my father was affecting my own masculinity. She sent information my way as I grew older, about a career in the military, or the police, and made the odd – indeed quite odd – remark about homosexuality as a disturbing and unhealthy condition. I wasn’t particularly inclined that way, though as a ten-year-old I definitely found some of the boys in my class as pretty (or ugly) as the girls. And later, my discovery of David Bowie, the most intense experience of my teenage life, had a clear sexual element.
The point here is that we’re plagued with traditional notions of masculinity, femininity and monogamy which will take time to break down. But changes are afoot, and the gradual fading of religion and the great work of pioneers like Beauvoir and many intellectual heroines before and after her are making for a much more female-friendly, not to say female dominant, political and social environment. Slowly slowly catchy monkey. Or in the case of bonobos, catchuppy monkey.
Bonobos don’t live in houses. They don’t have sex in bedrooms. And, like us, at least post-religion, they don’t have sex to produce offspring. It seems that, like dogs on their masters’ legs, they’ve learned about erogenous zones, but, being smarter than dogs, have taken that a step further in terms of bonding. Humans hide away to have sex, but consume ‘adult’ videos involving sex on beaches and other open air spaces, in bars, on stages, in public toilets, in palatial residences, in the best and worst of places. It’s as if we long to be open and brazen about our sexuality, but dare not.
I note that one of the biggest sex video industry in the world is in Japan, which is also, surely not coincidentally, the least religious country in the world. It’s also not exactly a haven of feminism, to be honest, and critics, including feminists, have often targeted the sex video world as, like prostitution, a haven of macho exploitation. I prefer to see it as, at least potentially, a haven of sex without love, but not without fellow-feeling. And certainly anyone familiar with the Japanese sex video industry would have to scoff at the characterisation I’ve heard, from conservative politicians among others, that a large proportion of the females employed in the industry, are entrapped and drug-addled (as is not infrequently the case, of course, with prostitution). Having said that, it’s still clearly an industry directed primarily at male consumers.
Feminists are generally divided about the industry, between those who want to kill it off and those who want, or hope, to transform it. In any case, one of the problems is that the industry compartmentalises sex. It becomes a product, most often accessed by men, alone, in their bedrooms, sometimes by couples or groups as an aid or an inspiration. It helps with fantasy and technique but has little if anything to do with fellow-feeling or – well, love.
And yet – what I note with Japanese sex videos is that they are more story-based than those of the Euro-American industry. Yes, the stories are often repetitive and predictable, and there’s too much ‘fake rape’, with the female invariably ending up ‘enjoying’ the experience, though it appears to be a fact that rape fantasies are common among women – an issue I feel way too squeamish to explore, at least for now. The point I’m trying to make is that many Japanese videos make the effort to place sex in a domestic or workplace context, to normalise it, even if in a somewhat ludicrous, and sometimes comical, way. I also note that sometimes they involve interviews with the performers before and after scenes, giving the impression of ‘happy families’, though there are definitely cases of coercion and the situation may be worsening. Again, more female empowerment is the key to changing this environment. The fact remains that both pornography and prostitution are signs of a culture that has never really come to terms with its sexual needs and its sexual nature. If we cannot accept that sex is healthy we will continue to pursue it in ways that are unhealthy – the drive will always be with us.
So what about love, again? And its relation to sex. As Beauvoir points out, the idea that two people will be able to satisfy each other sexually, exclusively, for decades, is ridiculous. Of course, many couples become increasingly comfortable with each other and co-dependent over the years – as do two dogs more or less forced to share the same home. This may be not so much a sign of love as of the standard living arrangements developed over the centuries in our civilised world – rows of few-bedroomed homes fit for maybe three to five people set out in grids of streets serviced with all the conveniences of modern life. We don’t build for anything like a bonobo world, understandably, and it’s hard to see beyond the reality that has shaped our whole lives. Still, I’m hearing a new term that might be worth clinging to – ‘ethical non-monogamy’. Something that might be worth considering once the hormones die down and the scales fall…
So that very bonoboesque idea I’ll endeavour to explore next time.
bonobos, chimps, humans, testosterone and the future, again…
What kind of societies did our primate ancestors live in? Could they have been more egalitarian than the ones we have now?
Angela Saini

hormones follow social evolution?
So I wrote a piece a few months ago on this topic, and my most recent piece starts to revisit the issue. Human males, at least in the WEIRD world, are experiencing reduced testosterone levels, which in terms of general health, is apparently a bad thing. Females on the other hand, already have testosterone levels at between a tenth and a twentieth those of males. What does this mean, for their health, and their behaviour? And what about testosterone levels of male and female bonobos and chimps, our equally closest living relatives, whose behaviour is so strikingly different from each other, and from us? To paraphrase Sabine Hossenfelder, ‘that’s what I’m going to write about today’. Or maybe not!
First caveat – it’s far from being all about testosterone, as regards behaviour or physicality. And I’m interested in changes to behaviour, re humans, rather than changes to testosterone. So I’m looking for clues in bonobos for promoting more of the changes I already see occurring in male human behaviour, partly due to the increasing empowerment of women. It’s likely that testosterone levels, and endocrine changes generally, will follow changes in social behaviour, rather than vice versa. But I’m certainly no expert.
I mentioned in one of my previous pieces that bonobo sexual dimorphism is equal to that of chimps, and of humans. However, I’ve since read that the sexual dimorphism is a wee bit less in bonobos than in chimps and humans (and given that the split between bonobos and chimps is quite recent, in evolutionary terms, that difference might continue to diminish, and even reverse, if both species manage to survive…). Every little bit helps in the power struggle, though it’s likely that female bonding is the real key to bonobos’ female dominance. A key to our human future?
Having said that, let’s still consider testosterone, and its reduction, and what it means for men in the future. Carole Hooven says this in Testosterone:
The consensus of experts is that testosterone’s main job is to support the anatomy, physiology and behaviour that increases a male’s reproductive output – at least in nonhuman animals. And men are no exception – T helps them reproduce, and directs energy to be used in ways that support competition for mates.
So it’s probably true to say that the reduction in T among males, in ‘developed’ nations, over such a short period in evolutionary terms, is more disturbing than exciting. However, male aggression and violence has long been a problem, to say the least. Hooven again:
Men are much more likely than women to be sexually attracted to women, and they are far more physically aggressive than women in every pocket of the earth, at every age. For example, they are responsible for around 70 percent of all traffic fatalities and 98 percent of mass shootings in the United States, and worldwide commit over 95 percent of homicides and the overwhelming majority of violent acts of every kind, including sexual assault.
All of which is hardly new news (though I’ve encountered disbelieving males), and in most mammalian species males are the more aggressive sex, but there are exceptions. Hooven cites the naked mole rat, the meerkat and the spotted hyena as examples of high levels of female aggression, but the role of hormones in these animals’ behaviour is complex and not fully understood. In bonobos, female dominance isn’t achieved in anything like the way male dominance is achieved in chimps. They do it though female solidarity, most often achieved through ‘sexual closeness’, to speak euphemistically.
Surprisingly, while there’s a massive difference between male and female human testosterone levels, this is not the case for bonobos or chimps. Male chimps ‘have on average 397 ng/dl testosterone, which is below the human male average’,
On this basis,I’d like to do everything I can to support female-female bonding. One inspiring story I first heard about years ago is a coalition of Palestinian and Israeli women trying to find a way around the impasse that exists within Israeli-Palestinian lands, where both groups have an in-group approach to the cultural history of the region they share.
These women — both independently and part of nonprofits and organizations — are working to bridge the gap, break down the walls — both literally and metaphorically — and build a world where Israelis and Palestinians aren’t enemies but neighbors and friends.
I suspect that the walls they’re trying to break down are those of macho insistence on the rightness of their ‘ownership’ of the land they inhabit. This insistence, and resultant violence, has resulted in trauma on both sides. Considering this trauma (naturally felt more on the militarily weaker side than the other), and the fact that both sides in the conflict are dominated by belligerent males, women are often reluctant to speak out about the situation, particularly on the Palestinian side. Take this example, from an article linked below:
We struggled to find a Palestinian woman in Gaza to openly speak in fear of retribution from Hamas, the “Palestinian resistance group,” or fundamentalist, militant, and nationalist organization that controls the region.
The same article features Jewish women, brought to Israel as children from persecution in Middle Eastern or African countries, expressing mixed feelings of gratitude and shock on being exposed to apartheid-style conditions in their adopted country, and Palestinian Arab women, dedicated to education and a historical understanding of the complexities of belonging and loss experienced by both sides of the conflict in the region.
All of this has taken me far from what I earlier promised to talk about – the more speculative question of our ancestry. Were those ancestors less or more violent than we are now? Or – was the CHLCA (the last chimp-human common ancestor) more like chimps (and humans) or bonobos?
One of the features most notable in ape and monkey societies – and also in humans – is hierarchy. We don’t notice it so much in our vastly populous society, in which we might be born to ‘unskilled’ labourers, teachers, small business owners, billionaire entrepreneurs or royalty – the gradations are so numerous that it may take us quite a while to know where in the hierarchy we belong, if we ever do – and whether we’re failing or improving in terms of the rung on the ladder we started out on. And there’s no doubt that failure or success can be measured in a much greater variety of ways than ever before, by ourselves or by anyone who chooses to measure us. In any case, the fact that there are people we ‘look up to’ – artists, scientists, parents, activists, monarchs, whatever – is an indication that we strive to better ourselves in an essentially non-egalitarian cultural environment.
But there have been notable changes in that environment in the last 100 years or so – not only with respect to female empowerment, but major transformations due to science and technology, in transport, communications, medicine and industry. We’re living longer, educating ourselves more, and working less hard, in a physical sense. We’re having fewer children, and a greater diversity of sexual relations. Though there are still many who ‘fall through the gaps’, we’ve developed human welfare systems to reduce dire poverty and to enable the intellectually and physically disabled to experience better lives than was previously afforded them. We’ve become generally more sensitive to the web of life from which our species has emerged, and what we owe to it and to the planet whose environment has enabled all living things to survive and more or less thrive. Some of these developments have long roots, but most of their fruits have been recent, though of course far from universal in human societies and nations. Democracies and open societies have proved to be the most healthful and beneficial for their people, and the general tendency has been to grow those societal types, through migration or activism against repressive regimes.
We live in a world of growing prosperity, often compromised by the belligerence and repression of the odd authoritarian national leader. It might seem a mite ridiculous to compare this massive and complex human population with the tiny bonobo world in a small corner of a sadly benighted African country, but I see some utility in the comparison, precisely because I see signs that our best societies are heading in the bonobo direction. Not that we’re getting hairier or more arboreal, but that we’re gradually becoming more caring and socially responsible, less violent and more sexually tolerant and diverse. The circle has expanded, the better angels of our nature are managing to prevail, and like David Deutsch, though perhaps for slightly different reasons, I feel little cause to despair of the human species.
References
Carole Hooven, Testosterone, 2022
Click to access Surbeck_et_al_2012a.pdf
https://qz.com/1033621/scientists-assumed-that-patriarchy-was-only-natural-bonobos-proved-them-wrong
https://www.sciencedaily.com/releases/2008/07/080715204745.htm
https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2010.1572
inspired by writers’ week, sort of – the internet, violence, testosterone and our future

Hmmm – needs further investigation. Vive les bonobos!
I spent some time at the Adelaide Writers’ Week tents yesterday, and heard a couple of remarks from speakers that exercised me in a negative way, so I thought I might air my grievances and expand on my thinking here. One was a quote taken, I think, from the historian and ‘public intellectual’ Bernard Lewis, on the influence of the internet on modern culture, and the other was a dismissal of the ‘better angels of our nature’ thesis of Steven Pinker.
I know Lewis only as a name, never having read any of his work, and I note that he died in 2018, just a few days shy of his 102nd birthday, so I can’t imagine him being an early adopter of the internet. I put his ‘public intellectual’ status in quotes largely out of jealousy, as I think I yearn to be a public intellectual myself, though I’m not sure. Anyway, from the little I heard of the quote, selected and spoken by Waleed Aly, Lewis was considering the double-edged sword of the internet in something like the manner of Marshall McLuhan in The Gutenberg Galaxy and The Medium is the Massage, only rather more negatively. I do recall dipping into McLuhan’s work decades ago, and finding it a bit over-hyped, and hyper. Anyway that’s enough of McLuhan. The concern being expressed about the internet was really mostly about social media and the ideological balkanisation it appears to foster. There’s some truth to this of course, which is why, without really thinking it through, I’ve been avoiding social media outlets more and more. Facebook lies dormant on my devices, and Twitter has come and gone.
But that is a minor part of the internet for me. Its advantages far outweigh the distractions of clickbait sites, and I personally consider it the greatest development in the dissemination of human knowledge at least since the invention of writing – and far more consequential than Gutenberg’s invention. For example, just in the past few months, without stepping outside my home, I’ve watched a lecture series from Yale University on the history of Russia, from the Kievan Rus to 1917 and the end of Tzardom; another lecture series – an Introduction to Neurology, from MIT, and a number of lengthy lectures from the Royal Institution, on palaeontology and on epigenetics, for example. I’ve subscribed to Brilliant.org and have completed 115 of their lessons on everyday science, and I’m boning up on the basics with Professor Dave’s Introduction to Mathematics series. Meanwhile, over the years I’ve observed Wikipedia growing in stature to become the first and best go-to site for learning about historical figures and events, as well as complex scientific subjects. And full scientific papers on just about every possible subject are becoming increasingly available online. I now have access to the greatest library in human history, which leaves me, at times, with a confused feeling – sometimes a dwarf, sometimes a titan. Bliss at this time it is to be alive, but to be young… I recall watching a video (online of course) about how a young African boy was able to build a wind turbine via online instructions, and so bring cheap electricity to his village. .. In short, the internet is an instrument – as is writing and the printing press. It can be used for a multiplicity of purposes, positive or negative. It’s up to us.
Second little irritant. I heard a brief segment of an onstage discussion between the philosopher and ethicist Peter Singer and a writer unknown to me, Samantha Rose Hill, author of a study on Hannah Arendt, about whether they viewed the future positively or negatively. Singer described himself as essentially an optimist, and spoke of his ‘expanding circle’ thesis. He also referred to Pinker’s The better angels of our nature, a book with which he was in broad agreement. The female writer, in her turn, said that she was definitely not in agreement with Pinker, after which I petulantly switched off.
I read The better angels of our nature, probably not long after it was published in 2011, and Pinker’s follow-up book, Enlightenment now, in 2018 or 2019. Right now I can say that I can’t recall a single sentence from either book, which is also the case for the hundreds of other books that have been consumed by the gaping maw of my mind. I might also say that I’ve written more than 800 pieces on this blog, and I’d be hard put to remember a line or two from any of them. In fact I’m sometimes moved to read an old blog piece – somebody has to – and find it amazing that I once knew so much on a topic about which I now know nothing.
But I digress. I don’t have to dig up my copy of Better angels to confirm my agreement with Pinker’s thesis. He wasn’t putting forward an argument that we’d become less violent as a species. He didn’t need to, because it was so obviously true, as anyone who reads a lot of history – as I do – knows full well. The real key to Pinker’s book lies in its sub-title, Why violence has declined. It seems to me that nobody in their right mind – or, I mean, nobody with an informed mind – would argue that the human world, a hundred years ago, 500 years ago, 1000 years ago, or, taking advantage of the knowledge provided to us from ancient DNA, 10,000 years ago, was more peaceful than it is today, on a per capita basis. The question is why.
Of course it’s impossible to keep track of the daily violent acts among a current global population of 8 billion, and to compare them to those of say, the year 1600, when the population has been estimated at about a half billion. And, yes, we’re now capable of, and have committed, acts of extreme, impersonal violence via nuclear weapons, but anybody who has read of the gruesome events of the Crusades, the Thirty Years War, the Scottish slaughters of England’s Edward I (a recent read for me), the centuries-long witch-hunts of Europe, and many other brutal engagements, as well as the public hangings, burnings, decapitations and tortures that were commonplace worldwide in earlier centuries, would surely not want to be transported back in a time machine without a cloak of invisibility or the support of a very powerful overlord – supernatural by preference.
Pinker’s book seeks to answer his own question with data and the possible/probable causal linkages, while recognising the complexity of isolating and independently weighing causes and correlations (he returns to this theme in his latest book Rationality, especially in the chapter entitled ‘Correlation and Causation’), including the spread of democracy, the growth of globalism and internationalism, the developing concepts of human rights, feminism, international monitoring agencies, and improved, less dangerous technologies re industry, medicine and transport, to name a few. Deaths can be no less violent, that’s to say violating, for being slow and accidental, after all.
Note that I snuck ‘feminism’ in there. Unsurprisingly, that’s the factor that most engages me. In the WEIRD world, thanks largely to Simone de Beauvoir (ok, a bit of flagrant heroine-worship there), feminism has been on the rise for several decades. During the same period, in the same regions of the world, male testosterone levels have been dropping. I would rest my case there, but I hear Mr Pinker tsk-tsking in the background. Seriously, the rise of feminism is surely one of a multiplicity of factors leading to a situation that medical researchers describe as ‘alarming’ – I’m not sure why.
Of course, testosterone is an important hormone, especially for men. On this medical website, Dr Kevin Pantalone, an endocrinologist, points out that, for males, testosterone helps maintain and develop:
- Sex organs, genitalia and reproductive function.
- A sense of well-being.
- Muscle mass.
- Bone health.
- Red blood cell count.
So, questions arise. Why are testosterone levels dropping (pace feminism), and is the drop significant enough to seriously compromise WEIRD men’s health? Well, according to the same website, different figures are given for what counts as a low testosterone level – 250 nanograms per deciliter (ng/dl), according to Dr Pantalone, and 300 ng/dl according to the American Urology Association. We’re not there yet, on average, but we’re inching closer, apparently.
So why the drop, apart from feminism? Some suggested factors include obesity (elevated BMI), reduced physical activity (however, endurance activities such as long-distance running and cycling have been shown to lower testosterone levels)., poor diet (but ‘several studies indicate that low-fat diets may lead to slightly lower testosterone levels‘), chronic and excessive alcohol consumption, lack of sleep (e.g. sleep apnea), and environmental toxins such as EDC (endocrine-disrupting chemicals – which sounds a bit vague).
That’s it. It all seems a bit thin to me – apart from the obesity bit. One factor they don’t mention, probably due to our overly polite society – or is it ‘wokeness?’ – is the serious drop in recent decades, and perhaps even centuries, of good old raping and pillaging. Nothing better for boosting ye olde testosterone, surely?
Seriously, would it be a terrible thing if male testosterone levels were reduced to those of females? And what about my darling bonobos?
So, human males typically have testosterone levels ranging from 265 to 923 ng/dl, while females range from 15 to 70 ng/dl. That’s a big big difference. Which raises the question – if females have such low testosterone levels, what about their bone health, muscle mass and sense of well-being? I suppose this is where we get into the finer details of endocrinology and evolution, but my uneducated guess would be that, over time, the endocrine systems of male and female humans have diverged somewhat, perhaps in response to different activities between the sexes. One way of getting more information about this – and this rather excites me, I have to say – is to look at the endocrine systems of largely female-dominated bonobos and compare them to those of chimpanzees. So that’s what I’ll be looking at in my next post. I can’t wait.
References
Stephen Pinker, The better angels of our nature, 2011
Stephen Pinker,Enlightenment now, 2018
https://pubmed.ncbi.nlm.nih.gov/33741447/
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/
understanding genomics 2: socio-sexual inequities and bonobos!

1 in 200 Men are Direct Descendants of Genghis Khan – Answers in Genomics!
Jacinta: So this blog piece is a bit of a change of pace from the science we’re obviously having trouble with – and I should mention that we’ve started watching the 11-part ‘Introduction to genomics’ videos online to help us with the basics – but what we’ve read in Who we are and how we got here and other texts is providing further evidence of a violent past that reflects an ancestry more associated with chimp-like behaviour, much exacerbated by the deadly weapons we developed along the way, than the bonobo togetherness that my endless optimism sees signs of in that part of the world that is increasingly empowering the female sex.
Canto: Yes, that in itself is a long story of gradual release from the masculinist Catholic hegemony of the medieval world, with its witch-hunts and its general suppression of female power and influence…
Jacinta: Going much further back in fact to the ancient Greeks and, for example, Homer’s Odyssey, and the treatment of women therein, as explored on this site years ago (referenced below).
Canto: Yes, this general improvement in the treatment of women, and of each other – the end of witch-hunts (I mean real ones) and public executions and torturings and so on – at least in English-speaking and Western European nations, has been highlighted in Pinker’s The better angels of our nature and other analyses. But we still have the Chinese Testosterone Party, the masculinist horrors of Iran and Afghanistan, and the macho thuggery of little Mr Pudding and his acolytes, to name but a few. The humano-bonobo world is still a long way off.
Jacinta: Yes the Ukrainian horror, getting all the airplay here that Mr Putin’s incursions in Chechnya, Syria and Georgia didn’t, reminds us that the horrors of two major European wars and Japan’s macho offensives in the first half of the 20th century haven’t been enough to reform our world – from a human one to a humano-bonobo one. But I doubt that genetic tinkering would do the trick.
Canto: Vegetarianism perhaps? But then, Hitler…
Jacinta: No easy solutions I’m afraid. But there are some who are interested in using genomics to highlight just how un-bonobo-like our past has been. Or rather, it’s not so much an interest, it’s more like telling the gruesome story that genomic data is revealing to them. In Neil Oliver’s History of Scotland, for example, he recounts how genomic data reveals that the Pictish men of the Orkneys and the northern tip of Scotland were almost completely replaced by men from Northern Europe, the Vikings, in the eighth and ninth centuries CE, while the female line remained largely Pictish. Slaughter, combined with probable rape, being the best explanation. Reading this reminded me of the chimpanzee war of the seventies in Tanzania, which admittedly was more of a civil war, and apparently less one-sided than the Viking invasion of the Orkneys, or the European invasion of the Americas, or the British invasion of Australia, but in some ways it was similar – an attempt, if not entirely conscious, to replace one population with another, and to the victor, the spoils.
Canto: Well, Reich is fairly circumspect in his book, but he does have a small section towards the end, ‘The genomics of inequality’, from which we may draw pretty clear inferences:
Any attempt to paint a vivid picture of what a human culture was like before the period of written texts needs to be viewed with caution. Nevertheless, ancient DNA have provided evidence that the Yamnaya [a relatively advanced steppe culture that emerged about 5000 years ago] were indeed a society in which power was concentrated among a small number of elite males. The Y chromosomes that the Yamnaya carried were nearly all of a few types, which shows that a limited number of males must have been extraordinarily successful in spreading their genes. In contrast, in their mitochondrial DNA, the Yamnaya had more diverse sequences.
and
This Yamnaya expansion also cannot have been entirely friendly, as is clear from the fact that the proportion of Y chromosomes of steppe origin in both western Europe and in India today is much larger than the proportion of steppe ancestry in the rest of the genome.
This is a roundabout or academic way of saying, or ‘suggesting’ (oh dear, I’m becoming an academic) that the Yamnaya forcibly replaced many of the males of earlier populations in those regions and interbred, in one way or another, with the females.
Jacinta: Yes, again very chimp-like, mutatis mutandis. The good thing is that we’re more and more coming to terms with our violent past – and I would love to be able to trace it further back, beyond Homo sapiens, or at least to the earliest H sapiens 100,000 years ago or so.
Canto: Well, I’m thinking that the CHLCA (chimp human last common ancestor) would be a good place to start, but we’ll probably never know what that population was like – was it more chimp-like or bonobo-like in its social (and sexual) behaviour? But there’s a huge difference between that CHLCA and us – just consider brain size.
Jacinta: But that’s a tricky measure – look at H naledi and H floresiensis. Chimps average around 400cc, gorillas 500cc, H naledi has been estimated at anything from 450 to 600cc, and H floresiensis, from the only extant skull, came in at 426cc. And those two hominins are considered relatively modern. Our brain size is about 1300cc. It’s over the place. But forget all these caveats for a moment, I’ve heard that we got our bigger brains courtesy of hunting big game and cooking meat – and the hunting at least strikes me as a macho activity, leading to a hierarchy of the big and strong, and so, alpha males and all the shite that follows…
Canto: Yes, and bonobos have evolved in a more physically restricted but resource-rich environment, and have somehow become less hierarchy-obsessed, though still hierarchical – the sons of the most powerful females apparently have a higher status in the male hierarchy.
Jacinta: Yes all this is important as we strive to establish a humano-bonobo world. In our incredibly diverse human world we have people dying of over-eating in some parts, and of starvation and malnutrition in others. But in the world of relative abundance that you and I live in, mechanisation and other technologies have reduced the need for physical strength, and testosterone levels in males have dropped rapidly in just the last few decades. We’re eating meat more than ever, but in our cities, nobody can hear the victims’ screams. And we don’t have to do the hunting and killing ourselves, so if we want to toughen up we have to do it via gymnasiums and sports, which are no longer gender-exclusive.
Canto: All this has little to do with genomics, but it seems to me that the macho-chimp orientation of early humans since the CHLCA has much to do with increased proliferation, diversity and inter-group competition for resources, especially over the last 20,000 years, or less. The domestication of horses and the invention of the wheel, and sophisticated sea-going vessels would have helped. Different groups advanced at different rates, with some developing better weapons – for hunting and then for warfare, and naturally they hankered for more territory to expand into, to ‘lord over’. Those more advanced groups became more hierarchical, and gaining more territory and ‘winning’ over more people became an end in itself – think of early versions of Genghis Khan and little Mr Pudding.
Jacinta: That’s why, like the female bonobos who gang up on uppity males before they can do too much damage, we need to stick it the Mr Puddings of the world – hit em hard, before they know what hit em.
References
https://www.discovermagazine.com/planet-earth/1-in-200-men-direct-descendants-of-genghis-khan
David Reich, Who we are and how we got here, 2018
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/