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ASTRONOMY ( HERCHEL) "IT'S LIFE JIM, BUT NOT AS WE KNOW IT" ALIEN LIFE IN FACT AND FICTION Dr Amanda Kear, BBC Bristol, on 8 June 2001 Humanity at the start of the 21st century is a complex, industrial-technological species. Our trade and communication across intercontinental distances is viewed as just another mundane aspect of modern life. What enabled this civilisation to arise? Are the BBC World Service, Eurostar and Coca Cola the inevitable endpoint of the evolution of intelligence? If there is life elsewhere in the Universe, can we expect it to have followed the same stages in cultural and technological development? The answer is that success or failure along this path may be deeply rooted in our biology and psychology. You may think that we are a fairly typical species, but the truth is humans are WEIRD even by Earth standards. This talk illustrated some of the necessary stages in the evolution of an intelligent, technological species and, using examples from media and literary science fiction, discussed what is and isn't realistic in our preconceptions of alien life. The speaker defined `universals' as a common or frequent solution to an evolutionary problem. For example, the eyes of vertebrates are very similar though they have evolved on Earth separately about 20 times. Where there is a suitable atmosphere, flight will always evolve and photosynthesis is the natural response to light from a parent star reaching an organism. By contrast, there are `parochials' which evolve in a limited number of species such as tails, bone, the same orifice for breathing and feeding, ball-and-socket joints and mammary glands to name a few obvious ones. Intelligence is a universal because it occurs in primates, octopuses and crabs to name a few. Such organisms find it useful to cope with a 3-dimensional world, with living in groups, with catching other animals and with teaching offspring. Intelligence leads to consciousness which manifests itself as awareness of others and self-awareness. Animals with higher intelligence are aware of other as another `self' in its own right. For example, gorillas do not share grief but chimpanzees do. When considering whether we might make contact with an extra-terrestrial intelligence, Dr Kear limited our definition of `intelligence' to `technological intelligence' - one which has at least the ability to make a device for communicating across space, such as some form of radio-telescope, even if they are not able to transport themselves physically. This necessitates the ability to make tools. Tool making requires the acquisition of knowledge about materials, which in itself contributes to the further development of intelligence, which leads to better tools and so on. Once a creature uses tools, it cannot live without them and refines them to a stage when an artefact becomes a work of art. In order to make tools, a creature must have manipulatory appendages. Dolphins, though intelligent, cannot become technologically intelligent because they do not have the appendages to make tools. Birds have developed a pair of their limbs for other purposes i.e. flight. Humans, the only creature on Earth with technological intelligence, have limbs The environment must be right for the manufacture of tools. Although dolphins and octopuses have high intelligence, the sea cannot produce a technologically intelligent creature because the materials there are, with the exception of stone, non-rigid. The effect of gravity on dry land is to produce rigid materials such as wood, bone etc. In addition, smelting to produce metals is only possible on dry land. However, the individual ability to make something must be combined with `group enterprise'. This arises through: • the overlap of generations in order to pass on knowledge (octopuses lay eggs but have no contact with their offspring), • altruism (concern for and support of others, exchange of goods and the development of currency to exchange and bargain for skills), • literacy and accountancy (records have to be kept for necessary planning - hunter-gatherers might have had some symbolism but had no need to develop record keeping). The acquisition of the above characteristics only comes with the development of an interactive society. Social interactions lead to greater security through membership of large groups - villages, towns. Families tend to group together to produce an `extended family' which makes it possible for the young to learn skills from others as well as their parents. Members of large groups cannot provide for themselves and currency is necessary to buy food produced outside and this currency is obtained by selling labour. This leads to the development of groups of individuals co-operating in a project (factories etc.) The downside to this is, of course, a non-egalitarian stratification. What makes the human species different? Animals tend to conform to one of two classifications: r-selected: quick and frequent breeding, short gestation period, quick maturation, short life-span, altricial young (helpless at birth, born blind and hairless, long dependence on parent) k-selected: slow and infrequent breeding, long gestation period, slow maturation, long life span, precocial young (born with hereditary skills, born sighted and hairy, short dependence on parent). Humans do not fit into this classification (nor do elephants) in that they are k-selected but have altricial young! Unlike other altricial young in the r-selected group, human babies are born with disproportionately large heads. In addition, as a result of walking erect, the human pelvis is modified so that human offspring are effectively born as premature foetuses! • The young are altricial. Offspring are totally dependent on the adult, which calls for extended lactation. • The period of dependence (childhood) is much longer than for other animals. • Sexual development is delayed to avoid conflict during the period of instruction. This means that humans have sudden sexual maturity (adolescence) rather than sub-adulthood in which the development is gradual. • The female of the species experiences menopause. This is connected to extended childhood - the last offspring appears well before the death of the parent and therefore has a better chance of being cared for. • Oestrus is `hidden' and humans are able to reproduce throughout the year. • Inefficient mating - takes as much as 6 months to conceive a child even when trying hard to do so. • Single birth is the norm - other animals tend toward multiple births. All these factors are essential to the formation of large social groups, which, in turn is necessary for the development of technological intelligence. What can we expect of any extra-terrestrial which makes contact with us Naturally, life can take myriad of forms as it does on Earth. Where there is water, there is a high probability of life of some form or other. Thus, the probability of life existing on a planet relatively close (say, within 10 light-years) to Earth is quite high. However, whether it has the type of intelligence and environmental factors necessary for it to make contact with us is quite another matter. It would need: • to be carnivorous in order to develop basic intelligence for hunting, • to be land-based (leading to the development of ball-and-socket joints) in order to access suitable materials, • to have prehensile limbs which would need an extension having a precision and a power grip and the properties of divergence, convergence, and opposability. This calls for the modification of limbs originally used for mobility, • To have moved from hunter-gathering into larger social groups, in order to develop co-operation, literacy and numeracy, and currency. The consequence of these requirements is that such an extra-terrestrial would differ very little from us! When reviewing the enormous number of chance factors which have directed our own evolution - the ascendance of mammalian life and the emergence of Homo Erectus being two of the more outstanding effects, it is, in the reporter's opinion, highly improbable that a similar technologically intelligent species has evolved within a communicable sphere (within, say, 100 light-years) of Earth. Amanda Kear's fascinating lecture has blown the lid off science fiction. Never again will we be so gullible when following Star-Trek and other adventures in Space. The Vulcans and the Klingons are as plausible as `Jim' himself, but what about "life - but not as we know it?" Richard Phillips |
