“So in twenty-five million years they mutated out of all recognition. Everything changes over a period of time and it’s no different with enzymes. Descendant strains from this one are probably still around but they don’t look the same. . . .” He caught the expression on Danchekker’s face. “No? . . . What’s the problem?”
The professor sighed a sigh of infinite patience. “We’ve been through all that, Paul,” he said. “At least, I was under the impression that we had. Let me recapitulate: Enzymology has made tremendous advances over the last few decades. Just about every type has been classified and catalogued, but never anything like
this one, which is completely different from anything we’ve ever seen.”
“I don’t want to sound argumentative, but is that really true?” Carpenter protested. “I mean . . . we’ve seen new additions to the catalogues even in the last year or two, haven’t we? There was Schnelder and Grossmann at São Paulo with the P273B series and its derivatives. . . Braddock in England with-”
“Ah, but you’re missing the whole point,” Danchekker interrupted. “Those were new strains, true, but they fell neatly into the known standard families. They exhibited characteristics that place them firmly and definitely within known related groups.” He gestured again toward the screen. “That one doesn’t. It’s completely new. To me it suggests a whole new class of its own-a class that contains just one member. Nothing yet identified in the metabolism of any form of life as we know it has ever done that before.” Danchekker swept his eyes around the small circle of faces.
“Every species of animal life that we know belongs to a known family group and has related species and ancestors that we can identify. At the microscopic level the same thing applies. All our previous experiences tell us that even if this enzyme does date from twenty-five million years back, we ought to be able to recognize its family characteristics and relate it to known enzyme strains that exist today. However, we cannot. To me this indicates something very unusual.”
Wolf gang Fichter, one of Danchekker’s senior biologists, rubbed his chin and stared dubiously at the screen. “I agree that it is highly improbable, Chris,” he said. “But can you really be so sure that it is impossible? After all, over twenty-five million years? . . . Environmental factors may have changed and caused the enzyme to mutate into something unrecognizable. I don’t know, some change in diet maybe . . . something like that.”
Danchekker shook his head decisively. “No. I say it’s impossible.” He raised his hands and proceeded to count points off on his fingers. “One-even if it did mutate, we’d still be able to identify its basic family architecture in the same way we can identify the fundamental properties of, say, any vertebrate. We can’t.
“Two-if it occurred only in one species of Oligocene animal, then I would be prepared to concede that perhaps the enzyme we see here had mutated and given rise to many strains that we find in the world today-in other words this strain represents an ancestral
form common to a whole modern family. If such were the case, then perhaps I’d agree that a mutation could have occurred that was so severe that the relationship between the ancestral strain and its descendants has been obscured. But that is not the case. This same enzyme is found in many different and nonrelated Oilgocene species. For your suggestion to apply, the same improbable process would have had to occur many times over, independently, and all at the same time. I say that’s impossible.”
“But. . .” Carpenter began, but Danchekker pressed on.
“Three-none of today’s animals possesses such an enzyme in its microchemistry yet they all manage perfectly well without it. Many of them are direct descendants of Oligocene types from the Ganymean ship. Now some of those chains of descent have involved rapid mutation and adaptation to meet changing diets and environments while others have not. In several cases the evolution from Oligocene ancestors to today’s forms has been very slow and has produced only a small degree of change. We have made detailed comparisons between the microchemical processes of such ancestral Oligocene ancestors recovered from the ship and known data relating to animals that exist today and are descended from those same ancestors. The results have been very much as we expected-no great changes and clearly identifiable relationships between one group and the other. Every function that appeared in the microchemistry of the ancestor could be easily recognized, sometimes with slight modifications, in the descendants.” Danchekker shot a quick glance at Fichter. “Twenty-five million years isn’t really so long on an evolutionary time scale.”