Alien fixation

This weekend belongs to the aliens. Manchester plays host to the International Conference on Alien Abduction, while Channel 4 gives lesbianism a rest and screens pictures claimed to be of dead space folk being dissected in Roswell, New Mexico, circa 1947.

The Roswell film is, of course, a hoax, following in the long tradition of the Turin Shroud, the Loch Ness monster and the Hitler Diaries. Each time new, astonishing evidence is discovered. Lots of journalists who ought to know better get very excited. Months, or even years later, the proof turns out to have been manufactured by a lab technician who needed the money to set up his own laundry business.

So far, alien abductions have failed to provide a piece of earth-shattering evidence. Nevertheless, there are thousands of (mostly American) men and women who say they were whisked off to spaceships and subjected to a series of rather intrusive and similar medical inspections. Women woke up to find themselves being gently probed, while men invariably came to with suction devices about their persons. One Scot told how a tussle with would-be kidnappers in a lowland forest had left his trousers "in shreds". Fortunately he escaped, and returned home to his wife, to whom he told the whole story.

What really convinces me that none of this is real is the physical description (and in the case of Roswell, the pictures) of the aliens themselves. In his book Abduction: Human Encounters with Aliens, John E. Mack (Professor of Psychiatry at Harvard Medical School), notes the common features attributed to aliens by abductees. They are humanoid, three to four feet tall, they have thin torsos, spindly legs, oval heads with big eyes, four digits, small nostrils and thin mouths. Worker aliens are smaller and move robotically, boss aliens are taller and have wrinkles. In the Roswell tapes the (doubtless latex) aliens are small, humanoid, with... need I go on?

Now this is passing strange. In an infinity of worlds and galaxies, with life evolving in any one of millions of different ways and in utterly different physical circumstances, how can it be that aliens all turn out looking like bald Michael Jacksons?

It gets even odder when you consider how accidental it is that we look like we do. But for a succession of great extinctions, caused by climatic change or meteor impacts, completely outlandish looking organisms might have inherited the Earth. At the end of the Permian period, 245 million years ago, vast numbers of species disappeared, including animals that resemble nothing currently on this planet. The survival of those organisms from which we evolved was entirely a matter of chance - a slightly different throw of the dice and all would have changed.

A smaller meteor or a bigger volcano and we might perhaps have emerged looking something like Wiwaxia, an animal of the early Cambrian period. In that case, our idea of physical perfection would have been to resemble a round and overfilled custard tart with eight almond slices sticking out of it. We would get around by emitting a cloud of flatulence from one of our eight anuses. And while speech would have been difficult, our smells might have been fabulously expressive.

What clinches this case, however, is the fact that the aliens not only resemble us so closely, but that they share our faults.

When, some years ago, a New Scientist competition invited readers to redesign the human body, first prize went to the engineer who invented a new knee - the existing one was deemed to be inefficient and prone to breakdown - a poor carry-over from our crawling days. Yet sure enough, the Roswell aliens - and all the others of course- have the same joints as we do.

You can just imagine how disappointed they were when they first started abducting us. "I am sorry, oh exalted Thrunk," apologises Dr Plish. "A zillion light years, and they've got crappy knees too." Impossible.