First of all, whether or not a creature adapts their environment has no bearing on whether or not they are an animal. To compare, it is like saying “Bats aren’t really mammals because they fly.” While it’s definitely true that bats are distinguished from all other mammals because they can fly, there is nothing about flight that is fundamental to the criteria of being a mammal. So this is what confused people in the previous thread – they think we are completely without definitions or even crtieria, that we are approaching everything like late neolithic man creating our first taxons on whatever whims we have at the time. But we do have definitional criteria, and whether or not a creature has special legal status within its own culture or can mow the lawn is not remotely on the table as a deal-breaker for the existing taxonomies. Perhaps in the way of fighting ignorance people shouldn’t just research what animals are, but what the definitial criteria are. In short, what kind of question is it? It is not a legal or philisophical question, it is a biological one. And as I said in the previous thread, supposing that you want the question to be “legal” or “philosophical”, what kind of debate are you hoping to have? Nobody’s going to argue that other animals DO (or even SHOULD) have equal legal status to humans. There’s not really another “side” to that question. What insight are we gaining? Is there really an adult among us noticing for the first time that humans open restaurants and pay taxes and cats don’t, and wondering at this realization?
Anyway, that’s all just in response to this arbitary “modify the environment” thing, which has nothing to do with whether or not we’re animals (did we stop being animals the moment we domesticated the dog? When we sharpened stones into axes? How did we fundamentally change biologically in that moment to become a completely different thing?)
All that being said there might be a good discussion with the legal rights for these humanzees, but whether or not we or they are “really animals” just obscures the question.