"Is it possible that we might have missed the intermediate stage?"
"I said 'stages'. Plural. Pick any known animal—any one—and tell me how many genetic changes would have to take place before you'd come up with an animal anything like this one." Again he tapped the bathygraph. "Take that eye, for instance. The lid goes down instead of up, but you notice that there's a smaller lid at the bottom that does go up, a little ways. The closest thing to an eye like that is on the hugl, which has eyelids on top that lower a little. But the hugl has eighteen segments; sixteen pairs of legs and two pairs of feeding claws. Besides, it's only the size of your thumb-joint. What kind of gene mutation would it take to change that into an animal like the one in this picture?
"And look at the size of the thing. If it weren't in that awkward vertical position, if it were stretched out on the ground, it'd be a long as a human. Look at the size of those legs!
"Or, take another thing. In order to walk on those two legs, the changes in skeletal and visceral structure would have to be tremendous."
"Couldn't we have missed the intermediate stages, then?" Dodeth asked stubbornly. "We've missed the intermediates before, I dare say."
"Perhaps we have," Yerdeth admitted, "but if you boys in the Ecological Corps have been on your toes for the past thousand years, we haven't missed many. And it would take at least that long for something like this to evolve from anything we know."
"Even under direct polar bombardment?"
"Even under direct polar bombardment. The radiation up here is strong enough to sterilize a race within a very few generations. And what would they eat? Not many plants survive there, you know.
"Oh, I don't say it's flatly impossible, you understand. If a female of some animal or other, carrying a freshly-fertilized zygote, and her species happened to have all the necessary potential characteristics, and a flood of ionizing radiation went through the zygote at exactly the right time, and it managed to hit just the right genes in just the right way ... well I'm sure you can see the odds against it are tremendous. I wouldn't even want to guess at the order of magnitude of the exponent. I'd have to put on a ten in order to give you the odds against it."
Dodeth didn't quite get that last statement, but he let it pass. "I am going to pull somebody's legs off, one by one, come next work period," he said coldly. "One ... by ... one."