(UFSCar -2000)TEXTO PARA A PRXIMA QUESTO:THE END O

(UFSCar - 2000)

TEXTO PARA A PRÓXIMA QUESTÃO:

THE END OF EVOLUTION?

The development of symbolic thought and complex communication did nothing less than alter human evolution. For one thing, high-tech transportation means that the world, though ethnically diverse, now really consists of a single, huge population. "Everything we know about evolution suggests that to get true innovation, you need small, isolated populations," says Tattersall, "which is now unthinkable."

Not only is a new human species next to impossible, but technology has essentially eliminated natural selection as well. During prehistory, only the fittest individuals and species survived to reproduce. Now strong and weak alike have access to medicine, food and shelter of unprecedented quality and abundance. "Poor peasants in the Third World," says University of Michigan anthropologist Milford Wolpoff, "are better off than the Emperor of China was 1,000 years ago."

And technology shows no signs of slowing down, which means that even dramatic changes in the natural world won't necessarily have evolutionary consequences. Argues Wolpoff.. 'We're not going to adapt to the next ice age by changing our physical form. We'll set off an atom bomb or set up a space mirror or whatever to control climate.' Manipulation of the human genome, meanwhile, will eventually let us change the basic characteristics of our species to order. Evolution by natural selection could be replaced, perhaps chillingly, with evolution by human intervention.

That's not to say humanity can't become extinct. A 50-mile-wide asteroid crashing down from space would do it. So could a sudden and thorough collapse of earth's ecosystem through pollution, deforestation and the like - unless we establish some colonies in space beforehand. But, whatever happens, the long history of multiple hominid species struggling for supremacy on earth is over. After millions of years, evolution by natural selection, operating blindly and randomly, has produced a creature capable of overturning evolution itself. Where we go from here is now up to us.

(From "Up From The Apes" in TIME MAGAZINE, August 23,1999, p. 5.)

A palavra "which" na frase "which is now unthinkable", constante da última linha do primeiro parágrafo, refere-se a