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Friday, January 3, 2014

113. Evolution of Language - 2



'As far as humans are concerned, language has got to be the ultimate evolutionary innovation. It is central to most of what makes us special, from consciousness, empathy and mental time travel to symbolism, spirituality to morality (Kate Douglas 2005).

'Somewhere in the last 100,000 years or so, human beings hit upon language. Human language must have seemed an odd-sounding innovation to the other animals around. But by allowing the expression of arbitrarily complicated concepts, human language allowed people to process information in a highly distributed fashion. The distributed nature of human information processing in turn allowed people to cooperate in new ways, forming groups, associations, societies, companies, and so on. Some of these new forms of cooperation proved strikingly effective, as various forms of distributed information processing, such as democracy, communism, capitalism, religion, and science, took on a life of their own, propagating themselves and evolving over time. It is the richness and complexity of our shared information processing that has brought us this far (Seth Lloyd, Programming the Universe).



Let us continue from where we left off in the previous post (Part 112). Deacon (1997) traces the evolution of social complexity by assuming that the early humans were dual-parenting. Since their sense of smell was not very acute (thus ruling out a role for chemical signalling through pheromones), some other type of sexual signalling evolved between the male and the female. This is how social communication originated and evolved as a kind of social hormone.

Other than sex, availability of food is the major factor determining the survival of a species. Males had to cooperate with one another for hunting. Deacon again: ‘Males must hunt cooperatively; females cannot hunt because of their ongoing reproductive burdens; and yet hunted meat must get to those females least able to gain access to it directly (those with young), if it is to be a critical subsistence food. It must come from males … [who] … must maintain constant pair-bonding relationships’.

This need for hunting in groups resulted in the evolution of a social structure implying a symbolizational solution to the problem of survival. This is because symbolic reference, as also speaking and thinking, are basically of a social nature. There was naturally a concomitant evolution of the speech organ (voice box).

Grooming

According to Robin Dunbar: ‘One of the most important ways that primate allies show their affection to each other is by grooming. Grooming not only gets rid of lice and other skin parasites, but it also is soothing. Primates turn grooming into a social currency that they can use to buy the favour of other primates. But grooming takes a lot of time, and the larger the group size, the more time primates spend grooming one another. Gelada baboons, for example, live on the savannas of Ethiopia in groups that average 110, and they have to spend twenty percent of their day grooming one another. … If we had to bond our groups of 150 the way primates do, by grooming alone, we would have to spend about 40 to 45 percent of our total daytime in grooming’.

The primates in the savannas also had to find food, and therefore such a large investment of time in grooming would have caused a non-sustainable work vs. life balance. Language emerged as a better way of bonding.



Evolution of word-speaking species

Humans began with sound language, gradually increasing the vocabulary. But there is a severe limit to how many sound calls you can have which still sound distinct. The next step in the evolution of language was a stringing together of sounds into specific sequences, namely words. Word-speaking species naturally had an evolutionary advantage.

Sentences syntaxing words were the next level of evolving complexity. Brain size increased concomitantly to understand and remember words, syntax, grammar, and sentences (Zimmer 2006): ‘A syntax-free language beats out syntax when there are only a few events that have to be described. But above a certain threshold of complexity, syntax became more successful. When a lot of things are happening, and a lot of people or animals are involved, speaking in sentences wins … Something about the life of our ancestors became complex and created a demand for a complex way in which they could express themselves … A strong candidate for that complexity, as Dunbar and others have shown, was the evolving social life of hominids’.

This social evolution of complexity is the advantage humans have over other animals. They have the capacity to introduce and expand complexity in social life, and development of language is both a cause and an effect of this capacity. As Kate Douglas (2005) said, ‘In a sense, language is the last word in biological evolution. That’s because this particular evolutionary innovation allows those who possess it to move beyond the realms of the purely biological. With language, our ancestors were able to create their own environment – we now call it culture – and adapt to it without the need for genetic changes’.



Whereas humans and chimpanzees have many genes in common, the expression of certain genes is more common in the human brain. Moreover, the brains of newborn humans are far less developed than those of newborn chimpanzees, and the neural networks of human babies are developed over many years of exposure to a linguistic environment. Through a continuous process of unsupervised learning (experimentation), supervised learning (from parents, teachers, etc.), and reinforced learning (the hard-knocks of life, and rewards for certain kinds of action), the child’s brain performs evolutionary computation.

With language came the possibility of emergence of ‘memes’. Language coevolved with memes. Next time.