I have scanned our days and all the ways we've planned our normal activities, searching for evidence that we may have been visited from the future, and I have found the only anomaly that fits this description to be ourselves. Before allowing disappointment to fully settle in, think about it this way. The future is that which already exists in eternity because every decision we make during our lifetimes literally creates the past. We are still in the process of mutually shaping that history because we are the agents sent from the future. One of the side-effects Temponauts must necessarily deal with is a complete disorientation with space-time; those who undergo being sent back into the past invariably come to believe that space and time are separate (to name but one of many bizarre hallucinations).
A time machine operates in a manner that is analogous with a boomerang. It also parallels the scope of an iris. Our descendants originally set the scope of their time machine to a series of certain dates, (thereby seeding portions of the galaxy with "in-utero" clones of themselves) in a bid calculated to alleviate the boredom of eternity with a "closed-loop system" of sufficient size to allow more variations. The experiment met with equal measures of success and failure. Their failure amounts to our creation.
Because while they aimed to merely maximize the variety of flavors within their closed loop (in an attempt to increase their menu of lifestyle choices) by purposefully setting the bar as high as possible ("aiming for infinity") what they managed to achieve went beyond their greatest expectations and escaped their wildest dreams: They accidentally created us all and (impossibly) themselves in the process! This unequivocal success generated the next paradox, and there remain whispers today passed along the generations that paradox itself runs the engines of creation.
The real nature of our descendant's time-machine experiment may only begin to be grasped when the realization sets in that every human being without exception was "seeded" from one such time traveller, and that we temponauts inhabiting Earth today have only incidentally come to be known as Earthlings. Our innate curiosity about extra-terrestrials stems from this great time travel experiment. What distinguishes us is the fact we didn't so much "arrive from the future" (remember, that is our own misconception as effectively "lost temponauts") as we arrove from Elsewher'n, that is to say, from outside this space-time realm altogether.
Our forefathers were bored and therefore created the Milky Way Galaxy as a time-machine experiment by which to re-launch themselves in their own image by sending their own stem cells with neutrinos to certain specified loci outside their own quantum realm thereby creating our portion of the universe. What they didn't exactly expect was to succeed in granting themselves an eternity of variants to further absolve them from boredom, except for the small issue that their own Temponauts grafted of their very genetics were doomed to endlessly perpetuate the very existence they had intended for themselves.
And so They wait, our Temporal Masters. They sigh, and perforce must await the day their travelers, spawned from their own dna, eventually return across the great expanse of time to their side. The masters of the human race have long ago learned from their mistake. Rather than succeeding in alleviating their own boredom, they rather accidentally created new lives which have been chasing after adventure ever since. The trick toward understanding this expanding dynamic lies in realizing the Gods themselves have come to question their own immortality even as they await their great time-travel experiment to come to fruition, all the while leaving us strewn in their path as their lost children growing to question our own sense of mortality.