Monkeying around with the origins of language
Published: 22 August 2006 (GMT+10)
Recently, a widely publicized study showed that when rhesus macaques heard recordings of different calls, they showed brain activity in the areas which, in humans, are associated with language.1 Not surprisingly, this is hailed as another proof of evolution. For example, one article about this study actually claimed in its headline, ‘Neural bases for language existed already 25–30 million years ago’, in an example of the responsible and moderate reporting that Christians have come to expect from evolutionists. However, as usual, what is actually described in these articles is far less sensational than what such headlines imply.
A group of scientists trained rhesus macaques to sit quietly in a PET scanner and played recordings of rhesus macaque vocalizations, interspersed with ‘non-biological’ sounds. The monkeys reacted to the vocalizations, but not to the other sounds, with brain activity in ‘Broca’s Area’ and ‘Wernicke’s Area’, two areas associated with language in humans. Based on this, the abstract of the Nature article reports that ‘this finding suggests the possibility that the last common ancestor of macaques and humans, which lived 25–30 million years ago, possessed key neural mechanisms that were plausible candidates for exaptation during the evolution of language.’
Despite the publicity that this study has received, there is nothing in it that tells us anything new about the capabilities of primates. Scientists have long known that primates are capable of learning a limited vocabulary and associating the correct meanings with it. We should not be surprised then if it turns out that primates also have a limited vocalized vocabulary.
However, this should not be mistaken for language. The study itself admits, ‘…these regions are clearly not performing linguistic computations in the macaque’, though it goes on to speculate about possible ‘prelinguistic functions’ that those areas of the brain might serve. Non-human primates have very limited vocabularies, and learn words one word at a time, unlike human children, who learn language in bursts.
In particular, non-human primates are incapable of using ‘recursion’, the process by which concepts are contained within concepts. An example of recursion would be, ‘He saw that the chimp could not understand him’; ‘the chimp could not understand him’ is the concept within ‘he saw’. Even a child could easily understand this sentence, but it would baffle any ape. Similarly, a child aged five or over can put himself into another person’s mind, while no chimp can (see the discussion of the ‘Sally–Anne test’).
It looks as if rhesus macaques have an amazing system of communication, with different calls to warn for different predators (for example, they would use one call to say, ‘a hawk is coming’ and another to say, ‘a lion is coming’), and a ‘vocabulary’ sufficient to communicate with each other. This finding, seen in the right light, is evidence for design, not evolution. After all, evolutionists cannot explain how even this very simple (when compared to human language) communication evolved.
- Ricardo Gil-da-Costa, Alex Martin, Marco A. Lopes, Monica Muñoz, Jonathan B. Fritz & Allen R. Braun, Species-specific calls activate homologs of Broca’s and Wernicke’s areas in the macaque, Nature Neuroscience 9:1064–1070, 2006. Return to text.