Thin edge

There is an edge to life,
A thin line and then a cliff.
This edge is where we find the most variation,
As each member of our species fights for their survival.
It's a constant marathon,
Falling behind won't mean trampling,
It will mean falling,
Falling to the harsh realities.
We must keep running to survive,
Succeeding to progress,
To be alone is failure,
With nowhere to go,
We die alone.