How important to the development of lasting civilization is the ability to survive? consider the possible effects of unforeseen disasters on a civilization

The ability to survive is crucial to a a civilization's continuity. Evolution basically means to adapt or perish. Only the strong (in every possible aspect) adapt, and with those strengths they become more resilient. Resilience is an advantage when dealing with adversities such as unforseen disasters. Once one experiences them, it becomes part of their resilience - at least for the survivors.