Nature proceeds in her seemingly purposeless circles. Until nudged to a higher orbit. Where does the impulse to this nudge come from? As esoteric as this topic may sound, I believe we could better understand evolution by looking at a few parallels in technology, literature/art and Hindu mythology.
Mobile Industry and the iPhone
The mobile industry was a fairly docile world. You had phones with increasing in-built memory, cameras with larger megapixels and larger screens. Forms of clam-shell, flip-phones and the works. In this calm market entered the iPhone. There was nothing in it that was not known earlier-touch interface, accelerometer and the suave graphics.
Yet the tying together, the overarching superiority of the coming together of these elements made it seem almost alien to our common perceptions. Everything, even the usually lumbering telecom providers, yielded to the vision of the iPhone.
Ever since, the mobile industry has not been the same. In trying to emulate and better a competing product, the entire industry is under a evolutionary pressure to up their acts.
2001 Space Odyssey
Moonwatcher, the pre-historic simian protagonist, leads a sedentary life in this unique novel/movie. Hunting for food, defending his pack of simians from another tribe of simians and so on. Until IT arrives, the monolith. Inscrutable and unlike anything Moonwatcher has ever seen. While monkeying around the monolith he touches it.
Nothing outside has changed. He is not hurt or burnt. Yet, imperceptibly, he has changed within.
The docile simian has learned of aggression. And in the next encounter with those of another tribe shows he means business. Until then death was an immutable reality, but now he knew and understood that death could be conferred by the strong.
Here again, the introduction of another principle, rendered artistically as monolith, determines the course of evolution. The presence of danger in the environment alone could not cause Moonwatcher to gather the skills necessary to survive by aggression.
An, as of now, unknown causal agent triggered a change within Moonwatcher.
Descent of an Avatar
The evolution of life proceeds in its Darwinian pace. The dinosaurs and the reptiles all. Some chosen for continuation and some for cessation. And then comes the impulse, that higher order and harmony which lifts life to the next level.
The first fish that peeped out of the water to breathe air. That transmuted suffocation into breathing. The first simian that stood up to gaze upon its environs. The mind that stumbled upon introspection. The first question. The first poetry. The first perception of anguish. Everything. Each was a push of our evolutionary impulse.
After each impulse we did not remain what we were just a moment ago.
The environs supported these but the Hindus believe that the cause for these high changes, these spurts and bursts of evolving life was the Avatar, a manifestation of the Supreme Divine who descends for a purpose.
There have been many Avatars. The popular ones are Narasimha, Sri Rama, Sri Krishna, with the detailed list available here. Follow the history of each and you find the evolutionary impulse working from the level of gross forms towards the subtle forms of Dharma.
A Common Theme
In each of these cases there is the steady progression of normal progress, until impelled by an element that exceeds our current common perceptions.
This impulse is named variously as genius, evolution and even called an Avatar by subtler perceptions.
Each is a facet of the one master impulse. And in that impulse will be the key that answers this manifold becomings of our individual selves and the Universe.