Baboons may offer clues to early human social evolution - Earth.com

June: Hey there, and welcome to Kindred Minds. I'm June — primatologist, science communicator, and someone who has spent a career completely enchanted by our closest relatives on this planet. Every episode, I bring you true stories about primates — stories grounded in real science, but told the way they deserve to be told: with warmth, with wonder, and with the honest recognition that these animals are not so different from us. I'm so grateful you're here, and I want to give a warm thank you to our sponsors — Ada, who helps organizations integrate A I into their workflows in ways that actually make sense; Ago Consulting, silicon development experts working across everything from A I to SoC; and Zen Semiconductor, an umbrella company with a remarkable portfolio spanning the silicon industry. We genuinely appreciate their support. Today on the show — baboons and what they might be telling us about how human society first took shape, the largest ape that ever lived and the mystery of why it disappeared, a discovery of a brand new monkey species with a very striking feature, and something that honestly stopped me in my tracks this week — the idea that the first primates didn't come from the tropics at all. So let's get into it. June: Okay, so let's start with cognition — with the question of how primates think, and what their thinking tells us about our own minds. And today I want to talk about baboons. Now, baboons don't always get the glamour that chimpanzees or gorillas do — they're not the ones on the magazine covers — but I would argue they deserve a lot more of our attention. Because researchers studying baboon behavior have been finding something really significant: the way baboons organize their social lives may actually offer us a window into how early human societies first came together. Here's what's so fascinating about this. Baboons live in these large, layered groups — and I mean genuinely layered, like there's real structure here. You have bonded pairs at the core, then family units, then clans, and then the broader troop. And that kind of multi-level social organization? That's not just interesting primate trivia. That mirrors the structure that anthropologists believe early human societies used. Small family units nested inside larger bands, nested inside even larger communities. It's the same architecture. Now, why does that matter for cognition? Because maintaining that kind of structure requires serious mental work. You have to track relationships — not just your own relationships, but relationships between others. Who is allied with whom? Who owes a favor to whom? Who is dangerous to cross right now? Primatologists call this social intelligence, and in baboons it is extraordinarily well developed. There are field studies showing that female baboons, in particular, form long-term bonds with other females — bonds that can last years — and those bonds have measurable effects on their health and survival. The baboons with the strongest social ties live longer. Let that sink in for a second. Social connection as a survival strategy. Sound familiar? Because it should. Because we see the same pattern in human health data — loneliness is a genuine health risk in people, and strong social bonds are protective. The biology is doing the same thing in both cases. And what baboon research is now helping us understand is that this social intelligence didn't appear out of nowhere in our lineage. It was being built, refined, selected for, across millions of years — in creatures very much like the ones we can still observe today out on the savanna. The baboon isn't a stepping stone we left behind. It's a living record of something our own ancestors were doing, and that is a remarkable thing to sit with. June: And that brings me beautifully into our second thread today — our shared biological recipe. Because when I talk about baboons or chimpanzees or any of our primate relatives, I always want to make sure we feel the depth of what "related" actually means. It's not just a poetic idea. It's written into every cell of every primate body on this planet. Let's start with the numbers most people have heard — that we share roughly 98 to 99 percent of our D N A with chimpanzees. And that figure is real and it is stunning. But I want to push it further today, because there's a story from this week that does something really interesting to our sense of primate origins. A new study — and this one genuinely surprised me — suggests that the very first primates didn't evolve in warm tropical forests the way we've long assumed. Instead, the evidence points to cold, dry environments in North America. Some of these early primates may have even coped with seasonal Arctic conditions — possibly by slowing their metabolism, maybe even by hibernating. Now, I want to be clear — this is an emerging finding and the science will continue to develop — but what it points to is something profound. The primate lineage, our lineage, may have been shaped not by paradise but by hardship. By dramatic climate shifts. By the need to adapt, to slow down, to survive the cold. And that completely reshapes the story of how we began. Because we tend to imagine our ancient ancestors in lush, sun-drenched forests. But what if resilience — metabolic flexibility, behavioral adaptability — was baked into the primate recipe from the very start? What if the thing that makes primates so cognitively and physically versatile is precisely because we were forged in difficult, changing conditions? That is a different origin story. And honestly, it feels more true to what primates are — including us. We are not creatures of one fixed environment. We are creatures who figure things out when conditions change. That trait — that flexibility — it's in the D N A. It's the shared recipe. And it goes back further, and was shaped by more, than we ever imagined. June: And I want to stay in that deep time for just a moment longer, because there's another story this week that belongs right here — the story of Gigantopithecus. Say that name out loud. Gigantopithecus. It even sounds like something from another world. This was the largest ape that ever lived. We're talking about an animal that stood somewhere around three meters tall — nearly ten feet — and may have weighed up to 600 kilograms. It walked this Earth for roughly two million years, which by any measure is an extraordinary run. And then, somewhere between 300,000 and 200,000 years ago, it vanished. Gone. And here's what makes this story so remarkable from a biology standpoint — scientists have been puzzling over the extinction for decades, and the leading hypothesis now involves something very specific: dietary inflexibility. Gigantopithecus appears to have been heavily specialized to eat forest foods — fruits, in particular. And when climate change began to shift those forests, to fragment them, to replace fruiting trees with grasslands and more varied landscapes, this enormous ape apparently couldn't adapt. It couldn't switch. The flexibility wasn't there. And so with the food went the ape. Now contrast that with what we just talked about — the emerging evidence that the earliest primates survived in cold, harsh conditions through metabolic and behavioral flexibility. The shared recipe that has kept primates going — including our own lineage — is adaptability. The capacity to change strategy when the world changes. Gigantopithecus, for all its size and for all its two million years of success, lost that flexibility. And it is a quiet, humbling reminder that no creature — no matter how large, no matter how long established — is guaranteed a future if it cannot bend. That lesson doesn't just belong to paleontology. It belongs to all of us. June: Now — the chimpanzees. Because I have to talk about this study, and honestly I've been thinking about it all week. Researchers studying chimpanzees in the wild have been revisiting what's known as the Gombe chimpanzee "civil war" — a real, documented series of events that Jane Goodall herself observed in the 1970s at Gombe Stream in Tanzania. What happened was this: a community of chimpanzees that had previously been unified slowly split into two factions — the Kasakela in the north and the Kahama in the south. And over a period of years, the Kasakela systematically attacked and killed the Kahama males, one by one, until the southern group was entirely wiped out. It was, by any honest measure, a war. Now, this has long been cited as evidence that lethal intergroup violence — organized, sustained, coalition-based violence — is something that exists in chimpanzees and therefore may have deep evolutionary roots in our lineage. But here is what the newer research is doing: it's looking more carefully at what actually caused the split. And what they're finding is that the breakdown of social bonds — the weakening of relationships, the fraying of the ties that held the community together — preceded the violence. The war didn't come first. The broken bonds came first. And that challenges a certain view of war as something that emerges from an innate, hair-trigger aggression. Instead it suggests that what we might call "war" — even in chimpanzees — emerges from social failure. From the collapse of connection. And I find that both sobering and strangely hopeful. Because if violence follows from broken bonds, then what prevents it is the maintenance of those bonds. The investment in relationships. The social intelligence we talked about at the top of the show. It's all connected — the baboons forming lifelong female friendships, the chimpanzee community held together by trust, and the way that trust, when it frays, can lead somewhere dark. We are not violent by default. We are social by design. And when the social fabric holds, something better is possible. June: And now I want to end today — before we wrap up — with something that fills me with pure joy. Because this week, scientists confirmed a brand new monkey species. A new one. In 2025. And it has an orange mouth. I'm not being poetic — this animal literally has striking orange pigmentation around its mouth, and it lives in the Brazilian Amazon, and it is a marmoset. Now, marmosets are these tiny, acrobatic, enormously charismatic little primates — they fit in the palm of your hand, and they have these expressive faces and this whole complex social world. And researchers, after careful study comparing genetics, morphology, and behavior, have confirmed that this orange-mouthed little creature is its own distinct species — not a variation of something we already knew, but something genuinely new to science. And here is the part that I want you to hold onto: it may already be endangered. We found it and it may already be slipping away, because its habitat in the Amazon is under pressure. So the discovery and the conservation concern arrive together, hand in hand, the way they so often do now. But I don't want to end on loss — I want to end on the wonder of the finding itself. Because the fact that in a world as mapped and catalogued as ours feels today, a new primate can still be found — a whole species, with its own face, its own social bonds, its own way of being — that tells you something important. The living world is still larger and more intricate than our knowledge of it. There is still more to find. There is still more to protect. And every new species discovered is a reminder that this planet is generous beyond our reckoning, and that the family of primates — our family — is still revealing itself to us. June: So that's our episode today. Baboons mapping the architecture of early human society. The first primates possibly forged in cold and hardship, not paradise. Gigantopithecus — giant, ancient, and gone — a lesson in the cost of inflexibility. Chimpanzee "civil war" reminding us that violence follows broken bonds, not the other way around. And a tiny orange-mouthed marmoset, new to science, asking us to pay attention. What ties all of these stories together — what always ties these stories together — is this: intelligence, social feeling, resilience, grief, love, the capacity to form bonds and to lose them — these are not human inventions. They are primate inheritances. They belong to a family that is much larger than our species alone. We share this planet, and we share this biology, with creatures of remarkable depth. And the more we understand them, the better we understand ourselves. Kindred Minds, brought to you by Ada, Ago Consulting, and Zen Semiconductor. If today's stories moved you or surprised you, I hope you'll subscribe — and share the show with someone who might love it too. Links to the research and articles we talked about today are in the link in show notes. Until next time — stay curious, stay kind, and remember: you have more family out there than you think.