The last fetter

are scientists free from scientisation and cultural influence? Can they be completely objective? To be sure, scientists have acknowledged their personal limitations. Even great physicists like Newton and Einstein acknowledged it. But when it comes to placing our species in evolutionary terms, scientists along with the humanists have believed that modern humans stand out. Homo sapiens subspecies sapiens is 'the best of the best', at the top of the evolutionary ladder. But recent anthropological studies suggest that there is a need to revise this opinion.

This comes as a surprise. Anthropologists in general have insisted that only modern humans can communicate intelligently through consistent production of sounds. Monkeys chatter, whales 'speak' to each other in squeals inaudible to the human ear, and birds sing and whistle. But only humans, they have said, have speech. This is not to say that humans cannot whistle like birds. In the Spanish Canary Islands -- the coincidence is striking -- the natives communicate over distances by whistling. But human speech is different from all other forms of animal communication in that human sounds -- words -- stand for conceptions, and communication is symbolic. Linguists and other scientists have agreed with this pronouncement.

Our predecessors the neanderthals ( Homo sapiens neandertalensis ), it was believed, had some form of speech. Around 30,000 years ago, the neanderthals competed with modern humans in the same ecological niches, were pushed to the margins and became extinct. Neanderthals were as tall as modern humans, had comparable brain capacities and a developed culture. So why did they become extinct? Going by what Nobel Laureate William Golding believed, the neanderthals communicated by means of some visual symbols (which was disadvantageous). But anthropologists suggested that the neanderthals simply had a less developed language.

Does this explain why the predecessors of the neanderthals, Homo erectus species like Jawa man, became extinct? Archaeologists, who depend on material evidence that they unearth, said that these species had a less developed culture -- meaning that the tools and weapons made by Homo erectus were not as good or as efficient. The implication was that H erectus could not kill and trap animals, cut trees, dig up edible roots -- and generally exploit natural resources -- as well as later humans. Palaeontologists, studying the fossilised skulls of these species, had also concluded that they probably did not have language. Their brain capacity was far below what was considered necessary for development of the vocal apparatus and meaningful articulation of sound.

Now, barely a month after archaeologists came up with evidence suggesting that Homo erectus built seaworthy craft 400,000 years ago ('Intelligent ancestors', Down To Earth , Vol 6, No 22) -- involving use of symbolic communication -- there is evidence that our ancestors could speak. Instead of measuring brain capacity, a team of anthropologists from Duke Medical Center at Durham, North Carolina, usa , took a different approach. They assumed that a long larynx (the 'sound box' in the throat), large pre-frontal brain lobes and a greater number of nerves leading to the tongue would be critical to the emergence of speech.

So they studied the hypoglossal canal, a hole at the bottom of the skull in the back, where the spinal cord meets the brain. Through this canal run nerve fibres from the brain to the muscles of the tongue. The wider the canal, the scientists assumed, the greater the number of nerve fibres that could pass through it; and the greater the number of nerves, the finer control a species could have over its tongue to make speech sounds. Comparing hypoglossal canals of modern humans, apes and several human ancestor fossils, they concluded that the canals of modern humans are almost twice as large as those of modern apes, which are incapable of speech. They also found that the canal size of australopithecines -- earlier human relatives that died out about one million years ago -- did not differ significantly from that of chimpanzees.

The results, the scientists said in a report published in the Proceedings of the National Academy of Sciences , "suggest minimum and maximum dates for the appearance of the modern human pattern of tongue motor innervation and speech abilities." To narrow the range, they examined skeletons of neanderthals and species of the Homo genus that lived up to 400,000 years ago. These included Kabwe specimens from Africa and Swanscombe fossils from Europe. The size of their hypoglossal canals fell within the range of those of modern Homo sapiens . This suggests that our ancestors were quite capable of speech.

Some scientists may not be convinced. The arguments, they may say, are tenuous. To be sure, interpretation alone is hardly science. But it has its place and is, to some extent, influenced by culture. Unlike animals, humans possesses culture and something apparently beyond culture -- science. But even Newton deferred to culture in dividing the spectrum into seven colours. A normal eye can easily distinguish more than seven shades in the spectrum -- the overlapping areas. Newton did not choose the number arbitrarily: seven symbolised perfection in his time. The belief that modern humans emerged suddenly as the most evolved species is an indicator of the anthropocentrism of our times. It is reminiscent of the church's argument that all species were created simultaneously.

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