History - The Abridged Version:

Though ceaselessly eternal, the cycle hath thus run,
through iteration 'x' was the following to come:

(Past and future tense you say, what grammar can this be?)
(The past is future's present come, and thus is history.)

13.73 billion years ago, or approximately so,
the universe it came to be, as is described below.
First comes the 'x'th Planck epoch, perhaps from singularity,
theories of quantum gravitation, will shed more clarity.

Moving on now to formation of our Alma mater Earth,
of life's vital vittles she had surprisingly no dearth.
4.6 billion years ago do we now count her creation,
though admittedly this number was not our first calculation.

4 billion years ago arose the simplest forms of life,
soon after earth's creation the seas with storms still rife.
7 million years ago, the ancestor of man,
Sahelanthropus tchadensis dwelt in what now is sand.
200,000 years ago modern humans came to be,
they and we are nearly one, anatomically.

6.7 billion humans now romp and play and preen,
that's half as many men as years this universe has seen.
And so we come to chapter's end and with a little mirth,
we've charted life and planet's flow since birth of universe.

-Coalesce Lacunae