There came a day when everyone's eyes were turned to the sky, to the exclusion of all else. Those who couldn't see with their naked eyes turned to their televisions, their computers or even their radios. They watched in helpless, disbelieving horror as an asteroid half the size of the moon approached with agonizing slowness and ground its bulk into the only orbiting body of this Earth. They watched as the two bodies fought for supremacy of the sky, and they watched them both lose. Then no one watched anymore; they just ran.
Every major and minor fault line around the world began cracking and shifting. Volcanoes, old and new, spewed their ash and toxic gases into the atmosphere. What the earthquakes didn't shake to the ground, the rain of rock smashed. And the people ran.
When the tidal waves came, they were so large that they reached far inland, trying their best to pull down the highest peaks and wash away all evidence of the great civilization of man.
The nuclear power plants that dotted the world were not exempt from the destruction, and the radiation man's arrogance had tried to harness escaped to mingle with the volcanic gases, ash and dust, to make a devastating soup that would affect all the generations to come.
When the rocks stopped falling from the sky, when much of the dust had settled, millions of people around the world found themselves still among the living. It was a mere pittance compared to the billions who had crawled across its surface before an asteroid wandered into their skies. But now they were faced with a far grimmer problem than they had ever faced before. Cities were leveled, farmlands were pulverized and roads were broken. Many people had no food or shelter and only a few were knowledgeable enough to improvise. But if mere survival were their only problem, they would have fourished again with scarcely a pause. What they faced with their meager skills was a type of nuclear winter, and millions more died of starvation and sickness before they figured out how to cope.
Winter came, and then winter stayed. Glaciers grew as the Earth struggled to wash the ash and dust from her skies, and within a few years, a new ice age was well underway. The people were reduced to living in hide tents because caves, if they could find them, were unstable due to the earthquakes that still shook the world as it strove to find a new balance within itself that did not include a moon.
The hurricane winds that swept the surface diluted and distributed the nuclear waste to the farthest corners, but it remained enough of a problem that, though there were deaths at first, they were relatively few and the people failed to make the connection. Only where the nuclear fallout was concentrated the most did the people see the danger and flee, but it still had an effect on every living thing, and mutations began to show up with each successive generation.
Ten thousand generations later, the mutations were no longer mutations; they were a fact of life. Some people could move objects, and at first, they used their skill to increase their success with the hunt by whatever means they could devise. Some people became sensitive to the noise in other people's minds, and they used it liberally to tell when people were lying. Some of the more drastic cases of mutation could change the shape and appearance of their bodies, learning to mimic other people, or even animals, down to the last hair.
As these effects became increasingly pronounced, the nomadic lifestyle of the people permitted them to segregate. Those who could read minds remained on the coast. Seeking refuge from the mental noise, they built boats and sought out islands far away from their fellows,where they continued to change. Those who could shape the bones and cells of their bodies sought out the heat far away from the forever snows, since they were also much more susceptible to arthritis and osteoporosis. There, they continued to follow a nomadic life, which allowed them to seek a middle ground between the heat their bones craved and the grasslands that could support their livestock.
Those who could move objects quickly learned to make good and valuable use of their skill. Causing death - even for food - was too frightening for the people to accept; the dangers of their lives were already numerous, so they learned to move injured flesh and bone instead, placing them in the right place to heal with the least amount of scarring or laming. Eventually they learned how to tell the difference between cells that belonged to the wounded person and matter that did not, and they learned to move the foreign matter out, thereby reducing infection. They became the healers, and since they did not seek segregation, they could be found in almost any group.
The greatest majority of the people remained normal. The self-segregation of the shape-shifters and the mind-readers, however, ultimately caused knowledge of them and the genes that produced their skills to fade from the rest of the population. And over the next ten thousand years, their cultures evolved along separate paths. The healers, however, so much needed by every group, were spread among them all and revered by everyone. Everyone respected a family who could claim a healer among their number.
All of the people, in their struggle to survive, did their best to preserve what they could of what they once were. Legends and tales were handed down, along with the skill for reading and writing. Old names were handed down too as one way of remembering the past. Someday there would be libraries again, and someday the people would reclaim their former greatness, if they could just remember enough. But life was hard. The machines of man's civilization had long since been reduced to dust and their great cities had been smashed to rubble. When the choice came between carrying food or carrying artifacts from the past, food won every time. Eventually, all they were left with were stories that had lost their meaning and the skill to write, though all they had to write on was leather, which, in times of hardship, was also left behind. More writings would be created in times of plenty.
For over a million years, the people struggled and the Earth groaned under its weight of ice. But life is a circle, be it large or small, and all things come to an end, or perhaps a new beginning.
As the forever snows began to recede before the warmth of the sun, societies began to grow. Men settled down and tilled the ground, raise livestock or fish the rivers and seas. Leaders built fortresses, and as is inevitable with the race of man, skirmishes ensued, and kingdoms were carved out. But all in all, these skirmishes were few and far between; the population was still sparse, no one was stepping anyone's toes too hard - yet.