The Gentle Giants of Ganymede

bear, there it was, coasting into orbit over Ganymede just like the first time. This time, however, the emotions that greeted its arrival were very different.

The exchange of messages recorded in Jupiter Five #146;s Communications Center Day Log was enthusiastic and friendly.

Shapieron Good afternoon.

J5 Hi. How was the trip?

Shap. Excellent. How has the weather been?

J5 Pretty much the same as ever. How were the engines?

Shap. Never better. Did you save our rooms?

J5 Same ones as before. You wanna go on down?

Shap. Thanks. We know the way.

Within five hours of the Shapieron touching down at Ganymede Main Base, familiar eight-foot-tall figures were clumping up and down the corridors at Pithead once again.

Hunt #146;s conversation with Danchekker had stimulated his curiosity about biological mechanisms for combating the effects of toxins and contaminants in the body, and he spent the next few days accessing the data banks of Jupiter Five to study up on the subject. Shilohin had mentioned that terrestrial life had evolved from early marine species that hadn #146;t developed a secondary circulation system because they hadn #146;t needed one; the warmer environment of Earth had imposed less strenuous demands for oxygen with the result that load-sharing had not been necessary. But it was this same mechanism that had later enabled the emerging Minervan land dwellers to adapt to a C02 -rich atmosphere. The terrestrial animals imported to Minerva had obviously possessed no similar mechanism, and yet they had adapted readily enough to their new home. Hunt was curious to find out how they did it.

His researches failed, however, to throw up anything startling. Each world had evolved its own family of life, and the two systems of fundamental chemistry on which the two families were based were not the same. Minervan chemistry was rather delicate, as Danchekker had deduced long ago from his study of the preserved Minervan fish discovered in the ruins of a wrecked Lunarian base; land animals inheriting such chemistry would be inherently sensitive to certain toxins, including carbon dioxide, and would require an extra line of defense to give them a reasonable tolerance if atmospheric conditions were extreme #151;hence the adaptation of the secondary system in the earliest land dwellers. Terrestrial chemistry was more rugged and flexible and could survive a far wider range of changes, even without any assistance. And that was really all there was to it.

One afternoon, Hunt found himself sitting in front of the view-screen in one of the computer console rooms at Pithead at the end of another unsuccessful attempt to uncover a new slant on the subject. Having nobody else to talk to, he activated his channel into the Ganymean computer network and discussed the problem with ZORAC. The machine listened solemnly without offering much in the way of comment while Hunt spoke. Afterward it had one comment. 'I really don #146;t see much to add, Vic. You seem to have got it pretty wrapped up.'

'There #146;s nothing you can think of that I might have left out?' Hunt queried. It seemed a funny question for a scientist to put to a machine, but Hunt had come to know well ZORAC #146;s uncanny ability to spot a missing detail or a small flaw in what appeared to be a watertight line of reasoning.

'No. The evidence adds up to what you #146;ve already concluded: Minervan life needed the help of a secondary system to adapt and terrestrial life didn #146;t. That is an observed fact, not a deduction. Therefore there #146;s not a lot I can say.'

'No, I guess not,' Hunt conceded with a sigh. He flipped a switch to cut off the terminal, lit a cigarette and slumped back in a chair. 'It wasn #146;t really that important, I suppose,' he commented absently after a while. 'I was just curious to see if the differences in biochemistry between our life forms and Minervan ones pointed to anything significant. Looks as if they don #146;t.'

'What were you hoping to find?' ZORAC asked. Hunt shrugged automatically.

'Oh, I don #146;t know. . . something that might shed light on the kinds of things we #146;ve been asking . . . what happened to all the Minervan land dwellers, what was it that they couldn #146;t survive that the animals from Earth could #151;we know it wasn #146;t the CO2 concentration now. . . . Things like that.'

'Anything unusual, in fact,' ZORAC suggested.

'Mmm. . . guess so.'

A few seconds passed before ZORAC spoke again. Hunt had the uncanny impression that the machine was turning the proposition over in its mind. Then it said in a matter-of-fact voice:

'Maybe you #146;ve been asking the wrong question.'

It took a moment for the implication to sink in. Then Hunt snatched the cigarette from his lips and sat forward in his chair with a start.

'What d #146;you mean?' he asked. 'What #146;s wrong with the question?'

'You #146;re asking why Minervan life and terrestrial life were different and succeeding only in proving that the answer is, #145;because they were. #146; It #146;s undeniably true, but singularly ineffective in telling you anything new. It #146;s like asking, #145;Why does salt dissolve in water when sand doesn #146;t? #146; and coming up with the answer, #145;because salt #146;s soluble and sand isn #146;t. #146; Very true, but it doesn #146;t tell you much. That #146;s what you #146;re doing.'

'You mean I #146;ve simply been working around a circular argument?' Hunt said, but even as he spoke he could see it was true.

'An elaborate one, but when you analyze the logic of it #151;yes,' ZORAC confirmed.

Hunt nodded to himself and flicked his cigarette to the ashtray.

'Okay. What question should I be asking?'

'Forget about Minervan life and terrestrial life for a moment, and just concentrate on the terrestrial,' ZORAC replied. 'Now ask why Man is so different from any other species.'

'I thought we knew all that,' Hunt said. 'Bigger brains, opposable thumbs, high-quality vision all in one species together #151;all the tools you need to stimulate curiosity and learning. What #146;s new?'

'I know what the differences are,' ZORAC stated. 'My question was why are they?'

Hunt rubbed his chin with his knuckle for a while as he reflected on the question. 'Do you think that #146;s significant?'

'Very.'

'Okay. I #146;ll buy it. Why is Man so different from any other species?'

'I don #146;t know.'

'Great!' Hunt exhaled a long stream of smoke with a sigh. 'And how exactly is that supposed to tell us more than my answers did?'

'It doesn #146;t,' ZORAC conceded. 'But it #146;s a question that needs answering. If you #146;re looking for something unusual, that #146;s a good place to start. There #146;s something very unusual about Man.'

'Oh, how come?'

'Because by rights Man shouldn #146;t exist. It shouldn #146;t have been possible for him to evolve. Man simply can #146;t happen, but he did. That seems very unusual to me.'

Hunt shook his head, puzzled. The machine was speaking in riddles.

'I don #146;t understand. Why shouldn #146;t Man have happened?'

'I have computed the interaction matrix functions that describe the responses of neuron trigger potentials in the nervous systems of higher terrestrial vertebrates. Some of the reaction coefficients are highly dependent on the concentrations and distributions of certain microchemical agencies. Coherent response patterns in key areas of the cerebral cortex could not stabilize with the levels that are usual in all species except Man.'

Pause.

'ZORAC, what are you talking about?'

'I #146;m not making sense?'