I've wondered often at how mystical states came about, states of mind that takes us out of the every day, such as the samadhi of buddhist meditation, or the zone of the long-distance runner. Assume, for argument sake, that such mystical states are an intrinsic part of our human heritage, then they must have evolved from a mental substratum dating back to a more primordial existence. The question then arises as to what possible use our distant quasi-monkey ancestors might have had for mystical-like states or mind.
Or to rephrase it another way, is there some kind of biological function that would require the evolution of mystical-like state of mind?
To explore this, we need a reasonable map of the evolution of humans from our common ancestor with other apes. First though, we need to define the set of features that distinguish us from the other apes. I think a reasonable set is: bipedalism, sweating, loss of hair, large brains, spoken symbolic language and hunting. How did these evolve and for what reason?
Although there is no official consensus to the answer, based on my reading around the topic, I'd hazard a guess that it happened in 2 basic stages, the first happening around 3-4 million years leading to the Aquatic Ape, and then later, around 2 million years ago, another transition resulted in the Running Ape, with the final pieces snapping in place with modern humans popping up around 200,000 years ago. By thinking through these transitions, I hope to identify the key adaptations that laid the foundation for modern states of mystical experiences.
The Aquatic Ape
What is clear is that permanent bipedalism happened around 3-4 million years ago. That's when we first find fossils of bipedal ancestors like Australopithecus. Careful analysis of the gait from the skeletal remains suggests that Australopithecus could walk but not run (Bramble & Lieberman, 2004, Nature 432:345 [PDF]). The brain is small, like a typical monkey brain, and it's probably safe to say that Australopithecus was not a tool user.
Surprisingly, another key feature that evolved with Australopithecus is the loss of body hair. Now you might be surprised by this because hair (or the lack of it) isn't preserved well in the fossil record, but recent compelling evidence comes from a rather ingenious bioinformatics analysis (Reed and coworkers, BMC Biology 2007, 5:7). This analysis focuses on, of all things, human hair lice. It turns out that humans, unlike other apes, have, not one, but two types of hair lice, one living in head hair and the other living in pubic hair. Chimps and gorillas on the other hand, have only one. The reason that humans have two types of hair lice arises from our nakedness over most of our bodies, and thus the two colonies of lice are isolated and have evolved separately. Indeed, it turns our head lice is related to chimp hair lice, whilst our pubic hair lice is related to gorilla hair lice.
The argument then is that when we lost our hair was when our hair lice split into two species (I first came across this idea in a wonderful Nova documentary about human origins). The bioinformatic study found that the two types of human lice shared a common ancestor around 3-4 million years ago, very close to the age of Australopithecus fossils. This suggests that Australopithecus was a butt-naked ape, every bit as hairless as we are, meaning that most artistic renderings of Australopithecus covered with monkey fur is wrong (for some gorgeous reconstructed images of our ancestors).
And if Australopithecus was naked, he probably sweated as well. It thus appears that 3-4 million years ago, our ancestors started walking on two legs about the same time that they lost most of their body hair and developed a sweating mechanism. What possible biological reason would result in these features?
In the case where one species evolve features quite different to their near relatives (other apes), I prefer explanations of evolutionary adaption that identify an environmental or functional factor that is markedly different from that which could be applied to their relatives. So the savannah ape theory is out, because there are plenty of other primates that live in the savannah but never needed to loose their hair or walk on two legs. Hunting or tool theory is also not particularly compelling as chimps are also known to use tools, hunt and eat meat. And neither is standing on tippy toes to look further out.
The only theory that fits the criteria of unique environmental factor is Alister Hardy's much maligned Aquatic Ape Theory that postulates that our ancestors spent some time evolving in water (Elaine Morgan, Scars of Evolution). One of the compelling attributes of the Aquatic Ape Theory is that the putative response of our ancestors to the water environment is incredibly similar to responses found in other aquatic mammals. This is convergent evolution, and makes the Aquatic Ape Theory rather attractive to my eyes.
In the Aquatic ape, swimming provides an excellent reason to lose the fur, in order to stream-line the body for swimming. Evolving in a water environment answers all sorts of interesting questions about our physiologies. Although we now have reasonably effective sweating mechanisms, we do tend to lose an awful lot of salt when we sweat. How did this happen? If we did lose our hair, and evolved sweating in sea water, then the loss of salt was not a problem at all.
More importantly, evolving in water solves one of the biggest conundrums of bipedalism: how to offset the huge physiological demands to walk continuously on two legs with a skeleton designed for knuckle-walking. Wading on two legs in water immediately takes away the physiological demands of bipedalism, with the immediate benefit of allowing breathing at much greater depths. Walking on two legs, however, is not unique to humans. For instance, although the bonobo monkey walks mostly on all fours, it can occasionally walk on two legs (Youtube clip), and has been observed to wade through rivers to get food. It is not hard to imagine Australopithecus as an accentuated version of the bonobo monkey that lost its hair.
The Running Ape
Nevertheless, the aquatic ape theory only accounts for the features found in Australopithecus. The other features of modern humans developed in the descendants of Australopithecus.
It's been suggested that the Pleistocene cooling that happened around 2.5 million years ago might have driven the Aquatic Ape back onto dry land. And about 2 million years, we start finding fossils of Homo Erectus, arguably the first ancestor that is physiologically very much like us. Analysis of the skeletal structure suggests that Erectus could run quite well (Bramble & Lieberman, 2004, Nature 432:345). There is a much better proportion of the legs for running. There is now a ridge at the back of the skull that attaches a tell-tale tendon for stabilizing the head during running. This tendon is also found in other mammals that run. Erectus was a Running Ape.
Crude stone arrow heads are also found with the fossils suggesting that Homo Erectus was a hunter, and ate meat. So here, we have a Running Ape that uses crude arrow-heads to hunt. However, it's always puzzled me how Homo Erectus could hunt with such crappy weapons. We can run, yes, but not really as fast as other mammalian predators like tigers and wolves, certainly not fast enough to chase down zebras or antelope, and throw crappy spear heads at them.
I found the answer to this conundrum in Christopher McDougall's Born to Run, which is a wonderful and encyclopedic book on long distance running. There, I came across the phenomenon of persistence hunting, an ancient method of hunting fleet-footed mammals. Persistence hunting is an ancient method of hunting that has almost died out. It is carried out by Kalahari bushmen (Youtube clip), and Australian aboriginal tribes. Persistence hunting works by basically running an animal to exhaustion over several hours of continuous running at roughly marathon pace. Although slow over short distances, humans are actually quite efficient runners over long distances. Hunting occurs by chasing a animal and not letting it rest, so after several hours, the animal collapses exhaustion. That's when our Running Ape can get close enough to basically stab the animal to death with a crude spear head. The skill in persistence hunting lies in the stamina required for the long-distance running and the ability tracking the prey over a vast area.
The reason that humans can outrun four-legged ruminants over a long distance turns out to be due to a surprising reason: sweating. Humans are one of the few mammals that sweat for cooling, and this turns out to be incredibly advantageous for long-distance running in hot scorched conditions. Most mammals cool by panting, which is incompatible with running. They overheat if they run long distances without stopping. In contrast, our Running Ape ancestor could maintain a steady pace whilst the liquid glistening on their naked skins keeps their bodies from overheating. Fianlly, the hunted mammal overheats, and collapses from exhaustion.
It was first proposed by David Carrier in 1984 (Current Anthropology, Vol 25) that persistence hunting was the adaptation that drove the evolution of Homo Erectus. But the most satisfying feature of the persistence hunting theory is that it provides a direct evolutionary link to the Aquatic Ape Theory. The unique physiological feature that allowed Homo Erectus to outrun its prey, was its ability to sweat to keep cool whilst running. This particular feature already exists as an evolutionary byproduct of our Aquatic Ape ancestors. Out of all the primates, only a descendent of the Aquatic Ape – one who had lost its hair and could sweat – would adapt to the new form of persistence hunting.
The Mental Requirements of Persistence Hunting
Now that we've established that persistence hunting may be the key driving adaptation for Homo Erectus, we can start exploring the cognitive demands of persistence hunting. Here, I believe, we'll find the evolutionary origins of mystical states of mind. From my reading of the literature, there seems to be three major cognitive developments required for persistence hunting:
an intrinsic reward for the action of running
a heightened awareness of the overall environment
ability to mimic the psyche of the animal prey
In studies of societies that undertake persistence hunting, it was found that hunters during the hunt often fall into a quasi-mystical state of euphoria. Running is considered effortless and enjoyable in itself. Considering that recorded hunts can last up to 8 hours, there is a tremendous delayed gratification involved. Thus, it is necessary to evolve an intrinsic reward for the running itself, in order to motivate our persistence hunter to carry out this otherwise exhausting activity. As such, our ancestor's brains evolved natural endorphins that are released with the physiological markers of long-distance running, such as regular intense breathing, and rhythmic motion.
For persistence hunting to work, the hunters must isolate and chase down a single animal. If you get mixed up and chase after different animals, you will not be able to exhaust it to collapse. Thus, one of the crucial abilities of a successful hunter is to track an animal over the landscape during an entire 8 hour run. The hunter has to develop the cognitive ability to maintain awareness of the prey in the vast expanse of the landscape. This is different to other mammalian predators, who only need to maintain direct visual contact as they run down their prey directly. The Hunting Ape must have developed an expansion of consciousness that defocuses from what is in front of you, diffuse over the vast expanse of the landscape in order to locate the prey anywhere on the horizon over the many hours of a chase.
Over a given chase, the hunters often lose sight of the animal, and no clear tracks are discernible. In such instances, the advantage goes to the hunter who could figure out which way the animal was likely to have gone. Our ancestors had to do it without tools such as GPS, satellite tracking, or knowledge of evolution. Instead, our ancestors found a short circuit to this information by evolving the ability to be "possessed" by the animal, or cognitively inhabiting the mind and thinking of the animal. Indeed, this is how modern day persistence hunters operate to predict the movement of the prey even when the trail was lost completely.
Mysticism is an Evolutionary Spandrel
In evolution, the arrival of a new trait opens up new direction for change. The trait may not have been directly selected for, just the accident of some other trait. Such traits then get appropriated for other biological functions. This is called an evolutionary spandrel, a term coined by Steven J. Gould, where he refers to architectural spandrels, spaces created by the intersection of arches, which were a byproduct of building dome structures, but appropriated for distinctive decorative elements found in many christian churches.
The unusual cooling method evolved in the Aquatic Ape, is a spandrel, as sweating allowed one of its descendants to develop into an efficient Running Ape, who learnt how to evolve a method of persistence hunting.
We modern humans have constructed societies (even global ones) that far outnumber the small bands of ~150 individuals that our paleolithic ancestors lived in. In order to cope with societies of such great density, it's my hypothesis that various religions were able to exploit the unique mental states of persistence hunting to re-orientating individuals to live more harmoniously in large numbers. In order words, the cognitive developments in persistence hunting are spandrels, which have been repurposed for religious spirituality.
De-centered States of Self
One obvious example is the runner's high described in the literature of long-distance running. Most runners experience a natural high after about 20 minutes of running, where euphoria takes over and the runner feels like she can run forever. This has obvious relation to the need to motivate our Running Apes ancestors to run a lot in order to hunt and eat.
There are also many examples of athletes who report that in certain instances, they experience what is now known as the "zone", where coordination and activity reaches a de-centered state, where everything just flows effortless. I would like to argue that this is invoking the primordial state of mind that is induced when a persistence hunter needs to de-center his consciousness over a vast landscape in order to keep track of his prey. I believe that this state of consciousness has been appropriated by modern spiritual practices to develop a de-centered sense of self. Practitioners who can experience is particular state of mind are much more functional in a heightened world of internecine conflict.
Practices such as yoga, tai-chi, and meditation tap into this ancient circuit to induce the euphoria and de-centered state of self originally evolved for persistent hunting. What is interesting is that these yoga and tai-chi focus on the body, perhaps identifying the muscles and motions that best elicits these states. As one of the most important aspects of long-distance running is the mastery of controlled efficient breathing, is it not surprising that yoga and meditation focus so much on the breath in order to elicit these states?
Possession by animal spirits
The other key cognitive development of persistence hunting is the ability to inhabit the mentality of the animal prey, which might better be described as possession by animal spirits. This kind of possession is almost a quintessential description of shamanic modes of thought, and provides a rather interesting interpretation of the cave paintings of paleolithic hunters. The purpose of these beautiful paintings, mainly of large wild animals, and rarely of human figures, have remained largely unexplained. Looking at it from the perspective of persistence hunting, however, these paintings become a natural expression of that key process of inhabiting the soul of the animal prey during a long and difficult persistence hunt.
This ability to inhabit the mind of other animals, opens up vast new potential for cognition. I believe that animal possession is the basis of a multitude of mystical states of minds, such as demonic possession, oracular prophecy, speaking in tongues, spirit channeling and charismatic prophecy. Evolution gave our Running Ape ancestor the ability to be possessed by the animal he was chasing down. This has bestowed on our minds, the cognitive potential to be invaded by the consciousness of all manner of strange beings outside of ourselves.