While tool use behaviours have been observed in primate societies, they vary between populations, and their growth is limited to direct visual observation and are, by and large, geographically isolated. As van Schaik noted; large groups thus have a distinct advantage over time; leading to both a statistically higher change of innovation and more minds in which to house behaviours, should disaster strike. If the Japanese macaque population were halved by some disaster, the behaviour patterns would survive because they have become so ubiquitous throughout the entire population. Should van Schaik’s comparatively smaller group of tool-making orangutans perish, the group on the northern shore would carry on oblivious to such innovations, as if they had never existed.
Anthropologist Luke Premo argues we may have lost more knowledge than we currently possess due to these types of cultural extinctions. Despite technology conferring a relative advantage to our remote, tool-making ancestor Homo Habilis, the small groups were still at the mercy of an unforgiving environment and the monsters of the Pleistocene. Premo argues “These small groups could have been exposed to fairly high changes of the whole group going extinct” . Human history can be viewed, in some sense, as a continual battle against information entropy and, as we will see, language evolved as a response to just these types of challenges.
As mentioned previously, early humans likely possessed a sophisticated nonverbal culture and rudimentary tool-making abilities. Starting in the early Palaeolithic, we see the emergence of technologies used for purposes of communication. Sally McBreathy and Alison Brooks point to evidence of the discovery of tools used for communication – pigments – at sites in the south of Africa that date back a quarter of a million years. Interestingly, these were found alongside early tools thought to be used for fishing, hinting at a link between complex communication and technology. Similarly, archaeologist Lawrence Barham has found corroborating evidence dating back to between 200,000 and as early as 400,000 years ago, near the Twin Rivers in Zambia . He and his team discovered a collection of hundreds of pigments of various colours, including brown, yellow, purple, blue and pink, which had been derived from nearby minerals. Nine of those “show signs of having been rubbed or ground to reproduce, presumably, a powder…. unambiguous evidence of the systematic collection and processing of pigments over a long period.” What these pigments were used for remains a mystery, as no artwork has been found, although one theory is that it was used as personal decoration, perhaps to imply some social status and cultural nuance. Certainly, if pigments were being manufactured, they would have been used for some form of communicative purpose.
A bone fragment of the pre-human Homo heidelbergensis – thought to be the joint ancestor of humans and Neanderthals – was uncovered in the Twin River cave. This is particularly interesting as studies of heidelbergensis skulls have determined they had auditory systems similar to modern humans and could have – in theory – understood language. We also know that, at the time, the groups of these creatures were organised enough to either take down large prey, such as horses and deer, or scavenge their remains while fending off other animals, something that surviving primates remain incapable of .
Is it possible that Homo heidelbergensis possessed some form of proto-language? Certainly in terms of volume, Homo heidelbergensis had a brain just as large as modern humans, thought we do not know if the various parts of the brain that related to language were proportionately as big. We do not know if they have the vocal dexterity to speak as we do, but it is possible that language may have taken a totally different form. Linguist Daniel Everett identified a form of language used in a number of Amazonian cultures, including the Banawás, Paumaris and the Satere-Mawes, called “high speaking”. A language based on whistling, it is totally separate from their day to day language and used to organise themselves when on the hunt, but also sophisticated enough to tell jokes and spread social information .
However, we cannot say with any certainly that they possessed such abilities. It could well be the case that, although increased usage of tools would allow more mental metaphors to be used to imagine scenarios, even as internal monologues, they could not transmit these inner thoughts with any degree of fidelity. Primatologist Jane Goodall describes this scenario as being “trapped within themselves”. While we may never be able to say conclusively that something resembling language was used by these remote ancestors, if they did, it did not evolve much past this rudimentary state for over a hundred thousand years, in which time Homo heidelbergensis split into two distinct sub-species; our ancestors, the Cro-Magnons and the robust, large-brained Neanderthals, who migrated out of Africa to Europe and the Middle East.
It is not until around 80,000 years ago that we see the next burst of technological development, again tied to early communications technologies. In the Taforalt Caves in Morocco, perforated ochre-smeared shells dating back around 80,000 years were discovered that hint at personal ornamentation; perhaps to confer social status. During the same period, in the Blombos Cave in South Africa, was found the first concrete example of our internal thoughts being recorded in external media: in this case a slab of ochre on which a human purposefully etched geometric patterns for reasons lost to time. This was found alongside evidence of a type of technology called Pressure Flaking (a deliberate process of sharpening stone), which predates its usage in Europe by tens of thousands of years. The presence of such “modern” technology at such a remote point in time indicates that something far more interesting may have been going on; the emergence of inter-group social networks.
Recalling the insights from van Schaik’s orangutan research, which relates population size to feedback loops of technological development, geneticists Adam Powell and Mark Thomas and archaeologist Stephen Shennan created a computer model to explore optimal population sizes for the generation of new technologies. The model was based on variables such as population density and whether or not ideas were shared between groups, and identified a tipping point at which new ideas became self generating . They concluded this density threshold was reached around 100,000 years ago, which is indeed what we have cursory evidence for at Blombos during this time. Commenting on this research in his book, The Origin of Our Species, biologist Chris Stringer argues that the network itself was crucial in the survival of technology.
“Cultural change in the middle Stone Age greatly accelerated, and the increased store of learning was beneficial to the survival of individuals and their groups. In turn this would have started a feedback mechanism, leading to further increase in population density and contacts, and so on. What is interesting about this work is that it suggests genetic continuity, large brains and intelligence on their own will not ensure success for human groups – the survival of knowledge itself is also vital” 
Ideas and behaviour patterns that were widely distributed and not isolated to a certain band or clan would have stood a better chance of survival, so the larger the social network, the more minds it can be copied to. Geneticist Matt Ridley proposes that the curious locations of shell and obsidian beads discovered during this era, in some cases hundreds of miles from their point of origin, hint at a primeval trade network along which cultural change could flow.
It also could be the case that our ancestors practiced exogamy, in which females were exchanged between tribal groups, perhaps to great ceremony. There is DNA evidence that this practice existed in the Neanderthals  and was widespread in early human cultures, where it remains tradition in parts of the world to the present day. Exogamy may have evolved as a way to increase genetic diversity and avoid incest but, as a consequence, also would have meant that females would have been the primary vector of cultural as well as genetic evolution throughout this crucial phase of history.
Whether cultural interconnection implies a shared language, or indeed any language in the modern sense, is unknown. We have no direct evidence for this, only tantalising hints at symbolic thoughts that suggest something like language may have existed. By this stage of evolution, even if ‘full blown’ language capabilities were not prevalent, nonverbal communication would have been at least as sophisticated as it is today, both within groups and between competing tribes. It is more likely that pigments, beads and other forms of communication technologies were used in inter-group communications and to denote rank and position without the need to transmit complex ideas verbally. This is evident in modern tribal societies; the Kīsedje and Kayapo people of South America wear plates in their lips to show social status, while Xavante men from the same region use wooden stakes to infer their role within a society.
But the primeval social network that spanned the prehistoric world was not immune from information entropy. Had things progressed in a linear fashion, humanity may have evolved its first civilisations in the savannahs of Africa instead of the arid wastes of Mesopotamia. But 73,000 years ago, fate intervened in the form of the Toba supervolcano. The gargantuan eruption, one of the largest in recorded history, was the equivalent of an 800 megaton explosion and led to a “nuclear winter” that blotted out the sun for almost a decade. It left a legacy of planetary-wide climate disruption that included massive droughts along tropical regions. The global human population, just flickering to life, dropped to as few as 3000 breeding individuals, devastating the newly emerging African social networks and destroying the knowledge within.
Pushed to the brink of extinction, what emerged from this epochal winter was a species transformed by catastrophe into a new type of entity; the mammalian super-organism.
National Geographic, “Hot Tub Monkeys” Offer Eye on Nonhuman “Culture”, 2004Ramachandran, Vilayanur, Mirror neurones and imitation learning as the driving force behind “the great leap forward” in human evolution, Edge.org, 2000
Himelfarb, Elizabeth J., Prehistoric Body Painting, Archaeology Magazine Volume 53 Number 4, July/August 2000