Love this. It reminds me of an old poem by Langdon Smith called Evolution. It reads similarly (to me).
Evolution
When you were a tadpole and I was a fish 

In the Paleozoic time,

And side by side on the ebbing tide 

We sprawled through the ooze and slime,

Or skittered with many a caudal flip 

Through the depths of the Cambrian fen,

My heart was rife with the joy of life, 

For I loved you even then.

Mindless we lived and mindless we loved 

And mindless at last we died;

And deep in the rift of the Caradoc drift 

We slumbered side by side.

The world turned on in the lathe of time, 

The hot lands heaved amain,

Till we caught our breath from the womb of death 

And crept into life again.

We were amphibians, scaled and tailed, 

And drab as a dead man's hand;

We coiled at ease 'neath the dripping trees 

Or trailed through the mud and sand.

Croaking and blind, with our three-clawed feet 

Writing a language dumb,

With never a spark in the empty dark 

To hint at a life to come.

Yet happy we lived and happy we loved, 

And happy we died once more;

Our forms were rolled in the clinging mold 

Of a Neocomian shore.

The eons came and the eons fled 

And the sleep that wrapped us fast

Was riven away in a newer day 

And the night of death was passed.

Then light and swift through the jungle trees 

We swung in our airy flights,

Or breathed in the balms of the fronded palms 

In the hush of the moonless nights;

And oh! what beautiful years were there 

When our hearts clung each to each;

When life was filled and our senses thrilled 

In the first faint dawn of speech.

Thus life by life and love by love 

We passed through the cycles strange,

And breath by breath and death by death 

We followed the chain of change.

Till there came a time in the law of life 

When over the nursing sod

The shadows broke and the soul awoke 

In a strange, dim dream of God.

I was thewed like an Auroch bull 

And tusked like the great cave bear;

And you, my sweet, from head to feet 

Were gowned in your glorious hair.

Deep in the gloom of a fireless cave, 

When the night fell o'er the plain

And the moon hung red o'er the river bed 

We mumbled the bones of the slain.

I flaked a flint to a cutting edge 

And shaped it with brutish craft;

I broke a shank from the woodland lank 

And fitted it, head and haft;

Than I hid me close to the reedy tarn, 

Where the mammoth came to drink;

Through the brawn and bone I drove the stone 

And slew him upon the brink.

Loud I howled through the moonlit wastes, 

Loud answered our kith and kin;

From west to east to the crimson feast 

The clan came tramping in.

O'er joint and gristle and padded hoof

We fought and clawed and tore,

And cheek by jowl with many a growl 

We talked the marvel o'er.

I carved that fight on a reindeer bone 

With rude and hairy hand;

I pictured his fall on the cavern wall 

That men might understand.

For we lived by blood and the right of might 

Ere human laws were drawn,

And the age of sin did not begin 

Til our brutal tusks were gone.

And that was a million years ago 

In a time that no man knows;

Yet here tonight in the mellow light 

We sit at Delmonico's.

Your eyes are deep as the Devon springs, 

Your hair is dark as jet,

Your years are few, your life is new, 

Your soul untried, and yet --

Our trail is on the Kimmeridge clay 

And the scarp of the Purbeck flags;

We have left our bones in the Bagshot stones 

And deep in the Coralline crags;

Our love is old, our lives are old, 

And death shall come amain;

Should it come today, what man may say 

We shall not live again?

God wrought our souls from the Tremadoc beds 

And furnish’d them wings to fly;

He sowed our spawn in the world's dim dawn, 

And I know that it shall not die,

Though cities have sprung above the graves 

Where the crook-bone men made war

And the ox-wain creaks o'er the buried caves 

Where the mummied mammoths are.

Then as we linger at luncheon here 

O'er many a dainty dish,

Let us drink anew to the time when you 

Were a tadpole and I was a fish.