Essentially, human beings have dominated the earth economically and culturally, and instinctively also being a prime factor to our ascendancy of civilisation and society development. However, the common injustice and exploitation of the other beings on this earth is likely, although arguably, due to the lack of social and presice intellectuality in most animals other than the intelligence of their instincts and survival methods. Our main cause of our success, I believe, is because of humans' ability to communicate with specific information of having unique and individual ideas and opinions and having the intelligence to act on those thoughts or to form an opinion of one's theory. The urge we have to discover the reason and purpose of things in our, perhaps risky, cloud of curiosity also concludes as to how things were created and developed to form and build a society based on mixed and popular judgements on certain behaviours or ideas. That is essentially how religion was created. However, it seems that our race has become boastful and over-confident on our success that we label and think of ourselves as "superior", despite countless amounts of proof that we aren't physically superior compared to our more combatably adapted peers. But our advanced mental and rational aptness of our human nature and our complex conceptuality outweighs most species, the outcome being that human life is pretty much segregated from the animal world.
Another cause for our success is the evolution of our physical state which has allowed us to complete certain actions that most species are adaptably restricted from. It gives us the variety of actions and gestres which we often use for communication purposes and also offers decisions when in particular situations, decisions that some beings are mentally or physically unable to do. Or you could think about our ability of self awareness and independence which taught us complex self thoughts allowing advanced individual theories and ideas. This has to be a distinctive aspect of a human being because it provides such freedom of thinking, almost blinding us and isolating ourselves from the main purpose of our nature, and that comes as a danger that we are still, even at our " superior" mental and emotional state, helpless to fend off other animals with the ability and instinct to crush us in one. But perhaps it is our fault which has caused certain animals to recognise the power humans crave and our pure isolation from the natural world is a perfect example of this.