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.

Henry: As you know, I address in a fictional context in “Search for Sungudogo” (now only 99 cents on Amazon) all three of your wishes, the discovery of life elsewhere in the universe, the discovery of intelligent life somewhere, and the documentation of non-human hominids in recent times (including the present) like, but later than, the “Hobbit” at Flores. (Drop me a line for a review copy.) In the revised version of the novella I also explain the origin of Penn and Teller. But I digress.

The chance of the existence of Homo notspaiens at present must be zero, unfortunately. But I do like the idea of proto-historical or historical cases. “Like” as in how a TV detective “likes” a particular suspect for a particular crime. Maybe it is just a hunch. A re-examination of all those cases in the sepia literature of little people or not-quite-humans thought to be imagination, serious confusion, or out and out racism may be necessary.

I’d like to put a finer point on the prediction though. The hominid needs to have existed after some key point in time (which may be hard to identify on the ground but that could be fairly easily defined as an archaeological or historical transition). For example, post first writing or post settled horticulture. Flores already fits the obvious next oldest criterion of post Last Glacial Maximum (LGM). Also, and this is not a requirement but it would be way cool, I would like them to have existed at the same time as and in the same region as the Wrangle Island Mammoths because then tiny people-like creatures could have hunted, or ridden, or otherwise lived among, tiny furry elephants.

Also, I’ll offer a prediction of where the hominid would have lived. It is most likely to be in an area where the landscape has two distinct habitats that are long term and well defined. One is a habitat likely to be inhabited long term by regular humans and the other where regular humans are likely to forage or visit only now and then, but where this second, marginal, habitat is livable. Also, it is more likely at the outer edge of post-LGM expansion, and in a region where human population would not have been dense prior to the great Exchange of Horticultural Products that began in the 15th century. (In fact if I were to pick the most likely local date formula for the extinction of Homo notsapiens globally, if there were a bunch of them, it would be the introduction of yams, manioc, maize, taro, or other staple plant brought in from the other side of the planet to grow locally.) This means the Flores hominid may have chipped its last rock when cassava or corn were first planted in the region, which would be very late and easily meet your criteria. I assume people are looking vigorously.

Yes, I just described Flores, but that’s the point. Those are the characteristics that allowed for the Indonesian Leprechaun. We might look at regions covered by the last glacial ice mass, regions far to the east of Africa, dense tropical rain forest, etc.

This also predicts that stories of “the little people” (or “the big people” depending) would be distributed more commonly in a certain region of the world’s map. Like this, maybe (and roughly):

I’ve ruled out the new world simply because. Bad reason, I know. It is entirely possible that the New World was thickly inhabited by Taltos and Leprechauns, the only really solid argument against that being a complete lack of evidence…

It is important to mention at this point that a third hypothesis, often classified as a subset of the Mutiregional model, had been proposed by C. Loring Brace. In this model a large continuous ancestral population was transformed regionally. The use of fire, Brace claimed, was invented in East Asia, and this transformed hominds in a certain way, and the use of improved projectile spears was invented in Africa, transforming those individuals in different ways. Specifically, the East Asians got smaller teeth and the Africans got more gracile bodies. These two transformations spread from their centers and overlapped each other and eventually transformed the entire global population.

Stringer’s new model isn’t like Braces in detail, but does account for the evidence better than both the Multiregional and Out of Africa models, assuming that evidence is sufficient to even develop a story for the rise of Modern Humans. Stringer still has a basal Modern Human form coming out of Africa, but then there is considerable interaction with extant non-Modern Human populations during which technologies, other aspects of culture, and genes, are exchanges. The results R us.

As you know, I’ve got my own theories about the origin of Modern Humans. I see the evidence of modern looking technology in Souther Africa quiet a bit before any evidence of symbolic behavior (i.e., the Fauresmith culture as documented by Peter Beaumont and others). A group of us led by Richard Wrangham published the idea that fire was controlled by early Homo and this transformed an asutralopith (roughly) like creature into Homo Erectus. By the time we get to the last interglaical, there is pretty good evidence of a very nearly modern human in Southern Africa and elsewhere on that continent. This, however does not obviate the idea of later spread and interaction with other populations, in accord with recent evidence from the genetics.

I don’t think we are there yet. I think we have a very coarse resolution and we are looking at a fairly fine tuned problem. Having said that, I would recommend Stringer’s book as an excellent window on the current thinking that does not privilege genetics (as is so often done these days in the larger discussion, because of the spectacular genetic finds) and incorporates both old and new evidence from physical and archaeological remains.

It is possible that I could assign this in an upcoming human evolution class. It is a good, easy read yet full of data and stuff. As one would expect form Chris Stringer.

More here, including lots of text. Teachers, you could probably find a use for this in your classroom.

Whether art is useful mainly as an indicator of something or whether art is “useful” as a trait, it is still useful as the former! It is probably not possible to produce what we call art with a brain that is not linguistic, and a linguistic brain is uniquely human. Or, perhaps art can be produced to some degree by non-linguistic brains but it usually is not. All the examples I can think of involve humans tricking some non-human animal into producing something that passes for (and may or may not be) “art.” In any event, the presence of art linked to hominid behavior in the ancient record may signal a human-like brain at that time and place.

Ancient art is diverse, and explanations for it are even more diverse. One thing most people who study ancient art agree on is this: It is best discussed over a beer.

And, that is what we are going to do. Tuesday night in Saint Paul. I hope you can join us: Art and Human Evolution at the Black Dog Cafe with Abbi Allan and Greg Laden

A few points to keep in mind for this discussion not otherwise covered above:

Just as we modern westerners have a hard time defining “what is art,” archaeologists may not agree with each other, or other observers, what the definition of “art” is. It is useful to consider Iain Davidson’s terminology which focuses on the medium rather than the meaning: PEDS (paintings, engravings, drawings, or stencils). Lots of things that are PEDS may not pass for art, but still may be usefully included in the discussion.

There was not a “creative explosion” 30 or 40 thousand years ago in Europe reflecting the sudden appearance of modern humans, signaled by a sudden appearance of lots of cave art. That idea has been out of favor for quite some time now. Except by those who still think it who are welcome to comment below.

The presence or absence of art or any particular form of art in an ancient context does not mean much. Entire complex artistic traditions are known to have been done mainly on perishable materials. There would be little archaeological evidence of such behaviors.

The earliest things that might be called PEDS are less art-like by modern and western standards than many later things. For example, I know of some unreported cupules that may be hundreds of thousands of years old (the oldest reasonably well dated cupules are between 30 and 40 thousand years old). Cupules are little semi-spheric “cups” worn into rock.

One of the earliest pieces of PEDS is this:

This is from Blombos Cave, South Africa and dates to about 75,000 years ago. The stone is ochre, a rock used to make red paint. Lots of other ochre was found at this site and in this or nearby layers, rubbed smooth from use in extracting or applying the pigment.

Sometimes “art” takes the form of tools made in a way that a modern, western human would think artistic. Is a very finely made stone tool produced with exotic (meaning, from far away) and especially nice-looking stone considered to be art? Of course it is, even if it is not PEDS. (Perhaps PEDS should be PEDSC where “C” stands for “Cool stone tool”). But would early examples of cool stone tools be included as art in a review of paleolithic art? Usually not, formally, though these things are often mentioned.

The above cited Blombos Cave item was found at a time period, roughly, where cool stone tools were abundant, sandwiched between time periods when they were less common.

This object dates to between 35 and 40 thousand years ago, and comes from Schelklingen, Germany:

This object dates to 33,000 years ago and comes from Germany:

Following these and a handful of other items, the art found at various places in the world comes in great variety, and pretty much everywhere. No major culture-historical time/space unit of humanity following about 40,000 years ago lacks art of some kind.

As we trace the history of art or PEDS back in time, the archaeological record passes through one or more major glacial periods, which effectively erases much of the archaeological record in cooler climates and affects human populations in the tropics a great deal. The shift from glacial to interglacial probably changes the nature of preservational environments in caves and other locations. Thus, conditions that would preserve a certain kind of material that might be art or have art drawn or engraved on it may be favorable during one climate phase and unfavorable during another. We would expect, therefore, a big drop-off in perishable art (including cave drawings) around 18,000 years ago as we go back in time, and several other drop-offs before that, which have nothing to do with production of art, but only with preservation of art.

There is art in Australia, Asia, Europe and Africa between 30 and 20 thousand years ago, prior to the 18,000 year climate period known as the Last Glacial Maximum. This indicates that art may have accompanied human groups generally as they expanded their range out of Africa. Anatomically modern humans probably existed 120,000 years ago in Africa. Anatomically kinda-modern humans are much earlier here and there in Africa. Neanderthals, who were very modern in many ways, and modern humans (who probably get more credit than they deserve for being different from Neanderthals) diverged about 500,000 years ago give or take a hundred thousand years. Fully modern human brain size, for example, probably existed at over 300,000 years ago. Certain aspects of stone tool technology that might (might!) signal human modernness of some kind might date to 250,000 years ago or, depending on what is important, closer to 400,000 years ago.

Thus we have several dates that are candidates for important aspects of modern humanness being in place: 500,000, 300,000, 250,000, 120,000. Then, we have a date by which art is assumed present among all humans: Call it 30,000. In between we have things like the scratched-up piece of Ochre from Blombos Cave. Somewhere in there … between several hundred thousand years ago and several tens of thousand years ago … the production of art as a feature of humans emerged. Probably.

We talk to author Christopher Ryan about his new book Sex at Dawn: The Prehistoric Origins of Modern Sexuality. We’ll discuss the most recent science and theories, and how social norms compare to our biological impulses.

This Friday. Details here. I may have to read this book.

For these reasons, a human evolution TOE will generally evolve into a zombie that won’t die and can’t be killed, potentially eating the brains of science geeks and graduate students for decades. Another example of a human evolution TOE is bipedalism. Here, the idea is that bipedalism explains everything. For a long time that TOE ate the brains of graduate students and the general public and even senior scientists. It no longer does for this reason: We now know that bipedalism evolved millions of years before many of the key human traits that we wish to explain. But the zombie is not completely dead. Many human evolutionists still make the claim that bipedalism was a very important step in human evolution, even though a) we can’t explain why it happened and b) there is no solid link between bipedalism and anything else. The fact that we are increasingly realizing that bipedalism evolved in many hominoid lineages may make this TOE go away eventually. So, for now, the Bipedalism Zombie doe not consume brains wholesale. It just scoops out a tablespoon here and a tablespoon there now and then.

The AAT is different from the Bipedalism TOE for a couple of reasons. For one, it was rejected a long time ago by almost all serious paleoanthropologists. It is quite possible that the fact that the theory was being promoted (but not originally generated) by a Welsh non-academic female and that she was being aggressive about it probably influenced more scientists (negatively) than many aspects of the theory. That would be unfair, and it probably was unfair. But after a while, the AAT began to demonstrate other reasons for its rejection.

The AAT, in its various forms over time, has addressed almost every general aspect of human anatomy and behavior and made the claim that an aquatic ancestry is the best explanation for that feature. Some of these claims were absurd. For instance, the “fact” that females have long hair was an adaptation to living in the water, where the long flowing locks of females would be used as life lines for her babies and toddlers (‘paddlers’?) floating around her.

One of the best possible forms of evidence for an aquatic phase would be to find other mammals that are not presently especially aquatic (or at least no more than humans), look for physical evidence of that adaptation, and then check for that evidence, surviving as physiological atavisms, in humans. Not finding such atavisms is meaningless, but finding them would be spectacular evidence.

For example, elephants may have gone through an aquatic stage, and this is in fact seen ontogenetically in their kidneys. Do human kidneys also show this kind of evidence? Well, no, sorry, they don’t. The fact that elephants would have gone through their aquatic phase much longer ago than humans does not help the AAT here.

When the AAT was first proposed, we had a murky view of human evolutionary history. At that time it was possible to suggest a single phase of evolution during which certain conditions prevailed, and from which a long list of human traits emerged. But since that time our understanding of human evolution has become more detailed and many of the human traits are now seen as having emerged at very different times over a multi-million year period of time. For the AAT to continue to explain all of these traits (hairlessness, bipedalism, large brain, head hair, body fat distributions, body size, leg length and form, atavistic webbed feet, seafaring, intense use of coastal resources such as shellfish, etc. etc.) it would have to be the case that our ancestors were ‘aquatic’ for millions of years.

For the entire time that the AAT has been extant, the theory itself has been rather murky. Just how aquatic? Were the babies born under water or on land? Was mating done under water? Was aquatic lifestyle facultative or did all hominids do this? All day every day? Was all the food aquatic? On top of this, only a few of the usual candidates for typical mammalian aquatic adaptations are seen in humans. Hairlessness and subcutaneous body fat were, of course, considered early on to be hallmarks of the aquatic adaptation. The fact that aquatic mammals do not vary in hairlessness (very much) and humans do is a problem. The fact that body fat distributions are sexually dimorphic seems to have been missed by the AAT. Or maybe not. Maybe there is a version where the females are aquatic and the males are not. They meet on the beach for romance. Thus, the link our species makes, psychologically, between beaches and romance!!! Aha!!! It explains everything!!!!!

Oh, sorry, … I’ve got control now, didn’t mean to go off like that…

So, you can see where the theory goes, and how in fact it can’t be stopped. The AAT is a zombie theory, untestable because so much of what it proposes has not been framed in a testable way. The AAT remains capable of consuming many more, still untapped “connections” and “explanations.” The AAT has consumed many brains, and not all of them particularly susceptible. Just recently, I heard from an excellent, unimpeachable source that a very famous person whom you have heard of is an AAT ‘believer.’ I found it hard to believe, but it is apparently true. Some day I hope to have a little conversation with this person!

AAT: The theory that keeps giving. And eating brains.

UPDATE: See this video just in.

DOMINGUEZRODRIGO, M., MABULLA, A., LUQUE, L., THOMPSON, J., RINK, J., BUSHOZI, P., DIEZMARTIN, F., ALCALA, L. (2008). A new archaic Homo sapiens fossil from Lake Eyasi, Tanzania. Journal of Human Evolution DOI: 10.1016/j.jhevol.2008.02.002