Self-perpetuation, the capability of something to cause itself to continue to exist, is one of the main characteristics of life. Organisms' capability of reproduction leads to self-perpetuation of the species, if not to the individual. Populations self-perpetuate and grow. Entire ecosystems show homeostasis, and thus perpetuate themselves. The slow modifying effect of succession and similar shifts in the composition of the system can, however, not be neglected in the long run. Overall, life's object's capabilities of self-perpetuation are always accompanied by evolution, a perfect steady state of the biological system is never reached. Sexual reproduction is also a form of imperfect self-replication and thus imperfect self-perpetuation because of recombination and mutation. Organisms are n