After thanking Kathi, I asked Dreiser where this monstrous thing had come from? From outer space? The Oort Cloud?
Not at all. ‘Olympus Mons,’ said Dreiser, then hesitated. ‘Very well then, Chimboranzo—’
Kathi immediately interrupted, saying, ‘It’s Chimborazo, Dreiser!’
He gave a grunt and grinned at her. ‘Chimborazo is entirely indigenous. Nor is there anything uncanny about it. Our belief is that it is the result of a curious form of evolution – curious, that is, from the point of view of one accustomed to thinking in terrestrial terms. Curious – but by no means irrational.’
But if this life form actually evolved on Mars, as Dreiser claimed, there would surely be evidence of other life in the atmosphere, I said. Not only in the atmosphere, but in the rocks and regolith. ‘Evolution’, after all, implied ‘natural selection’, so there must have been other forms of life with which this monstrous Olympus organism had been in competition. I remarked that it would be silly to turn our backs on Darwin’s findings, since natural selection was now a well-established principle.
Dreiser had adopted a slouching posture, as if scarcely interested in the topic we were discussing. Now he sat up and looked at me with a direct stare.
‘I am not disputing those principles, Tom. Far from it. But it is all too easy to fall into the way of thinking that how natural selection has operated in the main on Earth is its only method. Conditions here are vastly different from those Downstairs. Which is not to say that Darwin’s perceptions do not still apply.’
Of course conditions differed, I agreed. But I could not see how his Olympus could have extinguished all other life forms on the planet, simply by sitting there like a great lump, all in one place.
‘For some while we thought exactly as you do. I have to say it is a limited point of view. Mounting evidence that Olympus is a living thing has made us change our opinions, our rather parochial earthly opinions. In fact, evolution on Earth itself has not been entirely “Nature red in tooth and claw”. I could name many examples of cooperation between species that have led to vital evolutionary advantage. I stress that: cooperation, not competition.’
I supposed he was thinking of man and his long relationship with the dog.
‘Unfortunately we did not bring our loyal friend the dog here with us, more’s the pity. We will certainly need him when we travel towards the stars to face unforeseen challenges. We did bring all the bacteria in our stomachs, without which we could not survive. That’s a handy example of a symbiotic relationship.’
What could that have to do, I asked, with his Olympian organism wiping out the rest of Martian life?
‘That is not my argument. Not at all. There are many examples where symbiosis has played a vital role in evolution. Let’s take lichens. Two differing organisms got together, a fungus and an alga, to form the unbeatable lichen, the hardiest of terrestrial life forms. Lichens are the first to move in after a volcanic eruption has wiped a mountainside clean. Even we, resourceful humankind, depend on our bacteria, just as swarming microlife depends on us.’
We had found no lichen-like organisms on Mars, I argued, and asked where that left us.
‘Hang on. I’m not finished. I have some even more apposite examples of cooperation. There were times in the evolution of life on Earth when symbiotic relations have been absolutely vital.
‘Take the eukaryotic cell. This is the kind of cell of which all ordinary plants and all animals are composed. It’s a cell that contains a distinct nucleus within which chromosomes carry genetic material. It has long been established that the first eukaryotic cells came about by the union of two other more primitive types of organism, the earlier prokaryotic cell and a kind of spirochete. The development of all multicellular plants and animals – and humans – stems from this union.
‘Incidentally, on the subject of life, you might ask yourself how likely – what are the odds – of such a coincidence happening elsewhere in our galaxy. Long odds, I’d say.’