OK, let me explain.
First of all, SimEarth wasn't like SimLife was, or is. SimLife was more of a game, whereas SimEarth was actually a simulation - set the initial conditions, and see what happens. Yes, there were ways to interfere with the way things were going, but that wasn't the main point of it, as in the case of a game. That's why even the creators described it as a computer "toy" rather than a "video game".
But yes, I guess what I would be asking for, similar to those wanting a more "sandboxy" sandbox mode, is maybe a simulator mode.
As for the guy who says body parts are all that matters, well, that shows utter ignorance of modern studies of wildlife, both urban and in the wild. Intelligence is being selected for HARD in the modern world, especially amongst those critters most in contact with humans, or affected by human activity. I saw someone ask for a city biome, and that's exactly where intelligence comes in. Now imagine an urban wildlife simulator with an intelligence mechanic ...
It would be a nice additional feature, I think. As long as you're not an unwitting devotee of the philosophy of Descartes and think your fellow creatures are nothing but automatons. Hhis math was good, but his philosophy was bloody horrible.)