And what happened to her sister, who had a slightly different genetic makup. And a slightly different thought process. Such as "I'll go on eating this low quality diet". Meanwhile the sister who eats some meat, has the ability to move to a more inhospitable climate, but under-populated with her species. Thats because she and her clan can take advantage of the grass eating ruminants that are able to thrive on the poorer quality food in the grasslands. Even though her species cannot eat the grass directly, they have moved into a new environment. Now two the two populations are seperated by geography. Lets let some time pass. Time passes... (for you Zork fans).
Each clan thrives on different diets, occupying different niches. Are the different clans each adapting to their different environments in different ways? Are these adaptations causing some indviduals to prosper more than the others? Are the adaptations heritable? Hmmm we have a difference within the species. Perhaps the one species has split into two? Naaa. Only God could do that. And God would have to use big tools such as time, biology, geography... And we know that God lives in a very small box, and did not create those kind of things, nor would God use those kind of tools to modify his beings.
/Sarcasm (for those who have trouble seeing it)