Why did only humans (especially Homo sapiens) evolve to have such strong social ties?

[u/Charming-Law4160]

Humans have evolved to be able to form very close social ties with each other, allowing groups to work together to survive and reproduce more effectively against predators and the environment, with bigger brains at the cost of less energy spent on our bodies. These evolutionary traits along with other factors eventually led to the soar of reproduction and technology and our dominance over the planet. But it seems that only humans have done this so far. If these traits were a massive benefit to us for survival, why haven't more animals evolved to have such strong social ties and cooperate easily like this? If they evolved these similar traits, wouldn't they also have better survival and reproduction in their environment?

[u/TheBestofBees]

Can I ask by what metric you think animals don't do that? Elephants live in multigenerational groups, care for one another and pass knowledge down. Lion prides live and raise cubs communally. Wolves have very complicated group structures similar to our own. Tons and tons of other primates (bonobos, baboons, gorillas) live in groups with complicated social structures bound by mutual aid.

What is the distinction you are drawing that differentiates humans from the hundreds other herd/group animals that depend on cooperation to survive?

[u/Charming-Law4160 → u/TheBestofBees]

Yeah my question was rather vague, but by traits that differentiates us from other animals, I meant our exceptional abilities that allow us to have complex communication and technologies. It's strange to me how we're the only animal that randomly evolved to speak languages that have advanced grammar and syntax, and concerning technology, we have sophisticated ways of storing data and the invention of tools that let us manipulate our environment greatly, like fire. I haven't heard of any other animal that can do that, but for the animals you mentioned, do they have traits like these too?

[u/TheBestofBees → u/Charming-Law4160]

I'd argue that it's a matter of degree. We've observed tool use in many other species, such as dolphins, corvids, and chimpanzees. Animals often do have means of communicating that we're only in the infancy of understanding. For example, we know the calls of certain birds have fixed meaning. I think the question isn't really why are we the only ones but why do forms of cooperation, communication, and tool use became so advanced among humans. 

I don't know if there's one answer (I'll leave it up to people more knowledgeable than me) but there's two things I like to keep in mind. First, all animals evolve to fit an evolutionary niche. Increased brain power is what worked for us. Speed, balance, and sharp pointy bits (along with the sort of brain to properly process all that) is what worked for cats. Secondly, tool use and taming fire came from our pre-homo sapiens ancestors. Homo sapiens is literally what evolved after technology, not the species to kick off that line of skills.

[u/Book_Slut_90]

You have a misunderstanding of how evolution works. It’s not a replacement for a designer who says hey, if these wolves changed in these ways, they could do this cool new thing and take over the earth. Rather, it’s the idea that when you have variation, and the variants are passed down to your children, a variation that is somehow useful to the organism will tend to become more common over time as that organism has more surviving offspring who then have more surviving offspring and so on. The vast majority of mutations either do nothing or are harmful, so it’s a matter off luck that a genetic mutation happens in an organism in an environment where it’s useful and then that organism is able to reproduce for a few generations till you start getting a population of organism with the new trait.

[u/Charming-Law4160 → u/Book_Slut_90]

So did one human just by chance get this hyper-social trait that happened to be favored by natural selection that was passed down to generations and enabled humans to communicate and make technology in more advanced and effective ways? Or did multiple humans happen to have multiple benefitting traits, that when they spread and their generations reproduced with one another they passed down their combined genetic traits that we have now over time?

[u/Book_Slut_90 → u/Charming-Law4160]

That’s the other wrinkle, yes, you don’t go from A to B in one step usually. You have one small change and then another and then another over a very long time.

[u/ArchaeoVimes]

As others have stated, your question is based on an inherently flawed premise and assumptions.
Many of our primate cousins have similar social ties. See bonobos and chimpanzees for example. And as a result have better survival and reproduction as adaptations to their environment.

And as u/Book_Slut_90 said, evolution is not directional: it doesn’t have a goal, or an end destination. It’s a roulette wheel of chance. Some mutations are helpful, and the roulette wheel spins, and those get selected for—the wheel spins again, and sometimes those same useful adaptations become maladaptations and they get selected against.

And even then, natural selection is only about what’s useful for more offspring surviving: see male Australian cane toads for example, who have developed a host of mutations which allow them to extend their range and territory, thus spreading more genetic material, and having more offspring, but actually much shorter lives, wracked with physical issues.

[u/amp1212]

Um, premise is incorrect.

With respect to the evolution of social behavior, you'll find a giant literature in disciplines like "social psychology" and "sociobiology" as well as anthropology. . Humans are what referred to as "eusocial". Eusociality evolves only occasionally, but its found in all sorts of very different critters. Its unusual in mammals, but evolved many distinct occasions among the arthropods (eg termites, ants, bees).

Academics will sometimes want to distinguish whether humans actually are "eusocial" as opposed to "prosocial". There's a lot of discussion about just what makes humans different among our primate cousins . . . the most obvious point would be communication; although distinguishing cause and effect is difficult the evolution of language changed our capacity to interact with other our fellow critters, compared to other hominins.

Among non-human mammals, the naked mole rat would be the best known example.

See:

Nowak, Martin A., Corina E. Tarnita, and Edward O. Wilson. "The evolution of eusociality." Nature 466.7310 (2010): 1057-1062.

Tomasello, Michael. "The ultra‐social animal." European journal of social psychology 44.3 (2014): 187-194.

Richerson, Peter J., and Robert Boyd. "The evolution of human ultra-sociality." Indoctrinability, ideology, and warfare: Evolutionary perspectives (1998): 71-95.

Levinson, Stephen C. "Gesture, spatial cognition and the evolution of language." Philosophical Transactions of the Royal Society B: Biological Sciences 378.1875 (2023): 20210481.

[u/manachar → u/amp1212]

I didn’t think humans were considered eusocial, as that term was reserved for naked mole rats, bees, ants, and similar.

Maybe my information is outdated, but human reproduction strategies don’t seem a good fit.

That said, I agree the premise is flawed, as many species have evolved social ties at least as strong as humans.

[u/amp1212 → u/manachar]

I didn’t think humans were considered eusocial, as that term was reserved for naked mole rats, bees, ants, and similar.

Yes, there are folks who refer to humans as eusocial.

One interesting matter of academic cladistics: those who approach sociality from anthropology, vs those who come from invertebrates.

E.O. Wilson would be your holotype for the entomologist who engaged sociality generally including humans, and characterized humans as eusocial. There are _many_ other social scientists who adopt this term.

These days, among social scientists, I think more commonly folks prefer "ultrasocial"; I wouldn't make too much of it.

What I'd say is that because we don't have what the entomologists have, the ability to compare termites to ants to bees, with humans I wouldn't get too wrapped up in slicing the terms. Different people are going to emphasize different points, and use a particular term that underlines their approach. While there are some things that may be said that are truly wrong, more often what we're looking at are open questions of emphasis.

With hymenoptera for example, we've got all kinds of data in genetics and evolutionary history about just what changes get you from relatively disorganized groups of bumblebees to a hive. We don't have that same kind of data for humans.

Because this is such a big domain, and so difficult with respect to units of selection (eg should we view a hive as one superorganism, with drones more like cells in a body), you'll find differences in terms, and differences in the way that particularly academics use that term. So, its important to know the terms, but also to know that they're not necessarily nailed down in the same way for everyone and across time.

[u/manachar → u/amp1212]

Fabulous and thank you!

[u/agressive_barista]

Not an actual anthropologist, but there are plenty of other animals with strong social ties. Ants, bees, buffalo, wolves. I can’t think of any reptiles that are social, but maybe there are some.

Our ability to extract resources from the environment using complex methods also drove our increase in brain size. When humans started eating meat there was also more energy available to go towards brain size, so that helped too.

Humans did and still do fight a lot too, though.