There was only one criterion for membership in the Brotherhood—membership in the human race. No matter how decadent or primitive a population might be, if it was human it was automatically eligible for Brotherhood—a free and equal partner in the society of human worlds.
Kennon doubted that any nonhuman race had ever entered the select circle of humanity, although individuals might have done so. A docked Lani, for instance, would probably pass unquestioned as a human, but the Lani race would not. In consequence they and their world were fair prey, and had been attacked and subjugated.
Of course, proof of inhumanity was seldom a problem. Most alien life forms were obviously alien. But there were a few—like the Lani—where similarities were so close that it was impossible to determine their status on the basis of morphology alone. And so the Humanity Test had come into being.
Essentially it was based upon species compatibility—on the concept that like can interbreed with like. Tests conducted on every inhabited world in the Brotherhood had proven this conclusively. Whatever changes had taken place in the somatic characteristics of mankind since the Exodus, they had not altered the compatibility of human germ plasm. Man could interbreed with man—aliens could not. The test was simple. The results were observable. And what was more important, everyone could understand it. No definition of humanity could be more simple or direct.
But was it accurate?
Like other Betans, Kennon wondered. It was—so far—probably. The qualifying phrases were those of the scientist, that strange breed that refuses to accept anything as an established fact until it is proven beyond a shadow of a doubt. After all, the human race had been spaceborne for only six thousand years—scarcely time for any real differences to develop. But physical changes had already appeared—and it would only be a question of time before these would probably be followed by genetic changes. And in some groups the changes might be extensive enough to make them genetic strangers to the rest of humanity.
What would happen then? No one knew. Actually no one bothered to think about it except for a few far-seeing men who worried as they saw.
Probably.
Might.
Possibly.