The theory of Evolution had taught us to expect other worlds to have developed along alternate biological lines to our own Earth. The basic idea of random chance all but required that alien worlds be truly alien. But when we traveled to the stars, we found nearly every world that could be habitable, no matter how unlikely, was habitable. And furthermore, they all shared the same basic building blocks of life. Any animal born on Earth could live on the worlds we settled for hundreds of lightyears in every direction without any genetic modification at all. It was like the worlds were designed for us, and that shook the scientific community to its core.