"Our evolution" above is the evolution of the system that created us, the total evolution of Mother Gaia.  To speak more specifically of the evolution of humanity:

At the dawn of humanity, we are young eagles learning to fly.  Before, we couldn't even eat our food without Mother chewing it for us.  Now, we are ready to join Mother in the hunt.

Clumsy at first, we take to our wings in chase of game.  As we learn more and more from Mother, we revel in the grace of flight and the thrill of the hunt. We fly beside Mother, or even without her, working overtime so our nest can grow.

...and grow our nest does.  Many of us begin to take to the sky not to hunt, but to take delight in flying high, far and wide.  They find good hunting spots, and encourage and entertain those who are hunting.  We are prosperous.

However, in our prosperity we grow foolish.  Less and less venture out with Mother; instead they drift lazily on thermals, or frolic high above the clouds.  In our size and exploits that do no good to the hunt, we have developed an egregariously enormous appetite.  Mother is weakening under the demands we are making of her.  Our hunters are bringing back foods Mother cannot digest in her old age.  To top it all off, we have shat all over Mother's roost.

Mother is at such a point where she can barely hunt.  We need more people devoted to hunting, making sure to bring back food Mother can safely digest, and to stop shitting on Mother.  Slowly but surely we can nurse Mother back to health, if we rise to the occasion and become magnificent birds of prey, flying for the purpose with which Mother had in mind when she first showed us how to beat our wings.

It will be a long and hard hunt... But we can still fly playfully, zooming ahead and alerting the others of game with beautiful aerial acrobatics.  We can still fly high, as long as we look back down to coordinate our efforts and locate new sources of food.  Perhaps we can find enough food to fuel our long flights up to the thermals, but we must put hard work above leisure.

Mother's sickness has left us in a perilous situation, but she has taught us well.  By using her lessons effectively, we can restore her health and continue to learn from her, as she is the wisest teacher.