Romans 8:19-22 ESV
For the creation waits with eager longing for the revealing of the sons of God. For the creation was subjected to futility, not willingly, but because of him who subjected it, in hope that the creation itself will be set free from its bondage to corruption and obtain the freedom of the glory of the children of God. For we know that the whole creation has been groaning together in the pains of childbirth until now.
If you relate the Bible, as well as some other aprocryphal books such as The Book Of Enoch, Apocalypse of Abraham, and Book of Giants, we can attest that the "Fallen" have been on this Earth as long as mankind, or perhaps longer. In the books of Enoch and Giants in particular, it was told that the fallen Son's of God performed "experiments" with humans and beasts. Not only were their own progeny with the daughters of men enormous Giants, but the Watchers also created "monsters" and taught men how to defy nature itself.
That being said, how would we know what of this Earth is still part of God's design, and what has been manipulated?
If the underlying question of why God allows suffering must still be addressed, it can be explained in a very oversimplified manner. (Though better explained in a forum allowing for much more space) Do you think it better to have a father that always has his hand on you, ever keeping you from harm, never allowing you to make any decision that would bring about failure, or one that allows you to choose your way and even guides you when you ask? I think resentment for the first father would arise very early, and that child would never truly learn to appreciate, much less love, that father.
Super simple, but seriously, the consequence of choice is happenstance. Good, bad, indifferent, it doesn't matter. But we see in scripture, that one day His hand will be upon us once again, and evil will be destroyed.