Dark Ararat - Brian Stableford [165]
Matthew had become conscious of movement at ground level, and had to pause to direct Ike’s attention to it. Ike redirected the beam of the flashlight, quickly enough to display half a dozen leechlike worms as they turned with surprising alacrity and slid away. Knowing that they were probably harmless, Matthew didn’t think it worth interrupting his monologue to comment on their arrival and departure.
“If that had been the case,” he continued, “how would the adaptive radiation of complex forms have progressed? Maybe it would produce an ecosphere very different from that of Earth—but maybe not. Maybe the speculator would have decided that the principles of convergent evolution would still work to produce many of the same sorts of biomechanical forms. Some, of course, would be easier to produce under the newly imagined circumstances, and some less, but there wouldn’t be any reason to assume that any bioform that functioned reasonably well in Earth’s actual ecosphere wouldn’t work equally well in the hypothetical alternative.
“Now, of course, we have another example on which to draw. We have Tyre, our very own dark Ararat. And what do we find on Tyre? We find a world whose ecosphere contains analogues of many of the bioforms that function well in Earth’s ecosphere, but whose fundamental genomics are surprisingly complicated. We find that the bioforms in question are almost all chimeras, even if the great majority of the organisms so far observed are what would be deemed single-species chimeras on Earth. We find that although sexual reproduction is observable at the cellular level in meitoic fusions and separations of what would be somatic cells if they were parts of Earthly organisms, we don’t find any egg- and sperm-producing apparatus.
“In effect, the complex organisms here are capable of having sex with themselves internally, at the cellular level, swapping genes between their chimerical elements. But are they also capable of having sex with each other, not according to the various bird-and-bee transfer models that the complex organisms of Earth have produced but in a much more thorough, much more all-embracing fashion? And if not, what do they do instead to produce the variations on which natural selection–driven evolution works?”
This time it was Ike who spotted something moving behind Matthew’s back, and moved the camera in the hope of giving the audience a glimpse of it. Perhaps he succeeded, but by the time Matthew turned there was nothing to be seen, and only the sound of scampering legs to be heard.
Ike’s lips formed the word reptile, but he didn’t say it aloud. Matthew took some comfort from the fact that Ike seemed to be following his discourse intently. If he was getting to Ike, who was here in the midst of all this strangeness, surely he was getting to his target audience.
“Whatever they do,” Matthew said, wryly, “they don’t do it very often. They can’t, for precisely the same reason that our emortal cousins back home on Earth have had to revise their own reproductive arrangements. The longer-lived an organism is, the slower its reproductive processes have to be. Organisms that die as a matter of course have to replace themselves relatively quickly in order to maintain their numbers; organisms that don’t have to die match their rates of reproduction