Saturday, December 28, 2013

112. Evolution of Language - 1

'If there had been no speech, then right and wrong, truth and falsehood, good and bad, attractive and unattractive would not have been made known. Speech makes known all this. Worship speech' (Chandogya Upanishad, VII-2-1).

'A mostly Lamarckian process whereby evolution of a transformational nature proceeds via the passage of acquired characters, cultural evolution, like the stellar evolution before it, involves no DNA chemistry and perhaps less selectivity than biological evolution. Culture enables animals to transmit survival kits to their offspring by nongenetic routes; the information gets passed on behaviourally, from brain to brain, from generation to generation, the upshot being that cultural evolution acts much faster than biological evolution' (Eric Chaisson (2002), Cosmic Evolution).

Story-telling or spoken language was the first major invention of humans that enabled them to represent ideas with distinct utterances. And when written language was invented, we developed distinct shapes to symbolize our ideas. The evolution of language, speech, and culture are some of the causative factors in the rapid evolution of the size and capacity of the human brain. The emergence of human language has been a major milestone in the relentless evolution of complexity on our planet.

We 'know' what our thoughts and memories mean. But if we want to share them with others, they have to be translated into language. Our neocortex accomplishes this using what Kurzweil (2012) calls 'pattern recognizers', which have been trained with patterns that we have learnt for the purpose of using language.

According to Kurzweil (2012), language is highly hierarchical and it evolved to take advantage of the hierarchical nature of the neocortex, which in turn reflects the hierarchical nature of reality. Noam Chomsky wrote about the innate ability of humans to learn the hierarchical structures in language. This ability reflects the structure of the neocortex. Hauser, Chomsky and Fitch (2002) cited the attribute of 'recursion' as accounting for the unique language faculty of the human species. Recursion, according to Chomsky, is the ability to put together small parts into a larger chunk, and then use that chunk as a part in yet another structure, and so on, iteratively and hierarchically. That is how we are able to build the elaborate structures of sentences and paragraphs and sections and chapters from a limited set of words.

According to Richard Dawkins (1989), ‘most of what is unusual about man can be summed up in one word: “culture”.’ Of course, one must make a distinction between ‘culture’ and ‘society’. ‘A society refers to an actual group of people and how they order their social relations. A culture . . . refers to a body of socially transmitted information’ (Barkhow 1989). The term ‘culture’ encompasses ‘all ideas, concepts and skills that are available to us in society. It includes science and mathematics, carpentry and engineering designs, literature and viticulture, systems of musical notation, advertisements and philosophical theories – in short, the collective product of human activities and thought’ (Distin 2005).

It is notable that, on the biological evolutionary time scale, there has been an exceptionally rapid expansion of brain capacity in the course of evolution of one of the ape forms (chimpanzees) to Homo sapiens, i.e. ourselves. This has happened in spite of the fact that the genome of humans is incredibly close to that of chimpanzees. The evolution of language, speech, and culture are believed to be some of the causative factors for this rapid evolution of the human brain. Let us see how.

Homo sapiens was preceded by Homo heidelbergensis, which also had a fairly large brain, but was not very effective as a hunter. He was not able to establish ecological dominance over other animals, even after two million years of evolution. Our human advantage is believed to have arisen from the emergence of language. ‘No topic is more intriguing and more difficult to address concretely than the evolution of language, but … [it] is almost a kind of sixth sense, since it allows people to supplement their five primary senses with information drawn from the primary senses of others. Seen in this light, language becomes a kind of “knowledge sense” that promotes the construction of extraordinarily complex mental models, and language alone may have provided sufficient benefit to override the cost of brain expansion’ (Klein and Edgar 2002).

The reference to ‘the cost of brain expansion’ here is to the fact that in humans the brain takes up ~20% of the metabolic resources of the body, and the brain tissue requires 22 times more energy than a comparable piece of muscle at rest.

Deacon (1997) emphasizes the big difference between human language (talking) on one hand and the various modes of communication among other live entities: ‘Although other animals communicate with one another, at least within the same species, this communication resembles language only in a very superficial way - for example, using sounds - but none that I know of has the equivalents of such things as words, much less nouns, verbs, and sentences. Not even simple ones.’

Deacon (1997) continues: ‘Though we share the same earth with millions of living creatures, we also live in a world that no other species has access to. We inhabit a world full of abstractions, impossibilities, and paradoxes … We tell stories about our real experiences and invent stories about imagined ones, and we even make use of these stories to organize our lives. In a real sense, we live our lives in this shared virtual world. … The doorway into this virtual world was opened to us alone by the evolution of language, because language is not merely a mode of communication, it is also the outward expression of an unusual mode of thought  -  symbolic representation. Without symbolization the entire virtual world is . . .  out of reach: inconceivable . . . symbolic thought does not come innately built in, but develops by internalising the symbolic process that underlies language’.

Homo heidelbergensis had a big brain. But was he also a great symbolic thinker? Probably not. Deacon argues that probably a single symbolic innovation triggered a coevolution of language and brain-size. Greater brain power resulted in a greater capacity to symbolise, speak, think. The cascading effect led to more complex languages and more complex brains. But all this required social interaction and support: ‘Language is a social phenomenon. … [and] … The relationship between language and people is symbiotic’.

I shall continue with this narrative in the next post.