Imperial Theory of Evolution

According to Imperial scientists all intelligent life takes the form of humankind. Imperialkind is considered the true evolution of humanity possing the spaceflight gene and broad spread across know space. Concintrating in the Imperial core and frontier.
Beause the age of runins and historical evidence Imerial scientists believe that mankind evolved in a span of a few hundred years simultaniously on dozens of worlds, and in fact is still evolving on more worlds.
The oldest homeworlds of Humanity are located in the following star systems

1. Wolf 259
2. Cappella
3. Centauri
4. Sol
5. Rigel 

Fierce debate about which world is the oldest homeworld of mankind.

When Imperials discover uncontacted humans on a new world they are welcomed into the empire as fellow members of the same species - within a few generations any unique genetic traits are reduced a quirk as Imperials assimilate the new population. 
Imperial theories conclude that evolution of Humankind is linked to their environment, with the following beasts considered fundemental to the evolution of human society

• Rats
• Cats
• Dogs
• Cows
• Chickens
• Several species of fish
• Horses

In worlds lacking one or more of these animals any humans found are generally considered Abhumans or a long lost colony of another human civilization.

Type

Natural