Years ago I proposed a theory (not anywhere in print, just in seminars and talks) that went roughly like this. Humans hunt. Dogs hunt. Prey animals get hunted. Each species (or set of species) has a number of characteristics such as the ability to stalk, track, kill, run away, form herds, etc. Now imagine a landscape with humans, wolves, and game animals all carrying out these behaviors, facilitated with various physical traits. Then, go back to the drawing board and redesign the system.
The hunting abilities of humans and dogs, the tendency of game animals to herd up or take other actions to avoid predation, etc., if disassembled and reassembled with the same actors playing somewhat different roles, give you a sheep herder, a protecting breed of dogs (like the Great Pyrenees or other mastiff type breeds), a herding dog (like a border collie) and a bunch of sheep, cattle, or goats.
Even human hunting with dogs (not herding domesticated animals) involves a reorganization of tasks and abilities, all present in non-dog-owning human ancestors and wolves (dog ancestors), but where the game are, as far as we know, unchanged. Human hunters documented in the ethnographic record, all around the world, had or have dogs, and those dogs are essential for many hunting types. The Efe Pygmies, with whom I lived in the Congo for a time, use dogs in their group hunting, where they spook animals into view for killing by archers, or drive them into nets that slow the game down long enough to be killed. The Efe actually get a lot of their game by ambush hunting, where a solitary man waits in a tree for a game animal to visit a nearby food source. He shoots the animal from the tree with an arrow. But, even then, the dog plays a role, because the wounded animal runs away. The trick to successful ambush hunting is to do it fairly near camp so you can call for help when an animal is wounded. Someone sends out a dog, and the dog runs the animal to ground. And so forth.
Scientist and science writer Pat Shipman has proposed another important element that addresses a key question in human evolution. Neanderthals, who were pretty much human like we are in most respect, and our own subspecies (or species, of you like) coexisted, but the Neanderthals were probably better adapted to the cooler European and West Asian environment they lived in. But, humans outcompeted them, or at least, replaced them, in this region very quickly once they arrived. Shipman suggests that it was the emerging dog-human association, with humans domesticating wolves, that allowed this to work. Most remarkably, and either very insightfully or totally fancifully (depending on where the data eventually lead), Shipman suggests that is was the unique human ability to communicate with their gaze that allowed this to happen, or at least, facilitated the human-dog relationship to make it really work. We don't know if Neanderthals had this ability or not, but humans do and are unique among primates. We have whites around our Irises, which allow others to see what we are looking at, looking for, and looking like. We can and do communicate quite effectively, and by the way generally viscerally and honestly, with our glance. This, Shipman proposes, could have been the key bit of glue (or lubricant?) that made the human-dog cooperation happen, or at least, rise to a remarkable level.
The Invaders: How humans and their dogs drove Neanderthals to extinction, by Pat Shipman, outlines this theory. But that is only part of this new book. Shipman also provides a totally up to date and extremely readable, and enjoyable, overview of Neanderthal and contemporary modern human evolution. Shipman incorporates the vast evidence from archaeology, physical anthropology, and genetics to do so, and her book may be the best current source for all of this.
This is a fantastic book, and I highly recommend it. Shipman also wrote "The Animal Connection," "The Evolution of Racism," "The Wisdom of the Bones: In Search of Human Origins," and several other excellent books on human evolution and other topics. Shipman, prior to becoming mainly a science writer, pioneered work in the science of Taphonomy, developing methods for analyzing marks on bones recovered from archaeological and paleontologic sites, such as those marks that may have been left by early hominins using stone tools to butcher animals.
Seriously, go read The Invaders: How humans and their dogs drove Neanderthals to extinction.
Must be a great book! Rushing to buy it!
I once had a dog who communicated with her gaze very efficiently. She had medication for gastric problems, and when she felt unwell, would stare at me until I noticed, then turn her gaze to the top of the fridge where the medication was kept. She then looked alternately at me and the medication until I worked out what she wanted and gave her the tablets. She only asked for her medication when she was unwell, and the tablets didn't taste nice so she wasn't trying to get a treat.
The Neanderthals died out because they tried to domesticate the wrong species. So while H. sapiens was forging his productive relationship with wolves, H. neanderthalensis was engaged in a static staring contest with lynxes that alternated between "what?" and "so bored now".
Magma: Good one!
Two big questions here
A) why the assumption that Neanderthals could not communicate with their gaze? These were tool users, teachers, hunters. People who sat arround fires and had complex social interactions. More importantly, they were capable of socializing with humans. If gaze is key to humans, this suggests Neanderthals shared the ability to communicate and facilitate mating.
2) you need to accept an extremely early date for dog domestication to reach this conclusion. Archaeological evidence points to a date c. 15k bp. While genetic evidence may point to domestication just at the time of human neanderthal interaction, it would have been relatively uncommon and very tentative interaction between humans and wolves.
Added to my "to be read" list. Thanks, Greg.
What about cats?
Magma, you might be on to something.
Thadd, good questions. Shipman's idea does not rely on the quirk that the unique human trait (the whites of our eyes) emerged in humans and not neanderthals, but it is what she suggests as a possibility.
Neanderthals may not have simply been just like humans. Whether we think they were or not is more a matter of fad at this point, though I think no one sees them as senseless brutes any more.
Humans have a collection of traits. There is no clear way to know which needed to co-evolve. Hard to say which unique human traits they may have not had, and visa versa.
i don't have a problem with the dating of dog domestication. It has to be early and widespread if all foragers colonized all lands with them. (If that happened). The archaeological dates do not really inform us. Read Shipman's arguments on that.
Looks interesting! Thanks for sharing.
Every year, I make an introductory lesson on evolutionary biology to my students in physical chemistry. The focus is "what makes humans peculiar animals". And there are lots of features that are peculiar to humans; a very curious species. The whites of our eyes are a nice addition to the list, Others are the prorturing chin, the large number of sweating glands, the lack of a baculum in males, and more. Most are easily explainable in terms of evolutionary biology, some are rather hard: why did we (males) lose our penile bone? There are explanations, but none really convincing
Fascinating post, but I would think it is just an assumption that neanderthals didn't have dogs. The first possible dog is 32k old from Altai, and Hss is not known to live there at the time, though Neanderthal and Denisovan were. Dogs apparently lived in caves with Homo Erectus in China over a hundred thousand years ago, and monkeys have been folmed "domesticating" puppies and indoctrinating them into their clans.
It is my no means clear that modern humans had domesticated the dog before Neanderthals were extinct or virtually extinct.