conservation

noun6

1. •
   The act of preserving, guarding, or protecting; the keeping (of a thing) in a safe or entire state; preservation.
2. •
   Wise use of natural resources.

   • “My father had ideas about conservation long before the United States took it up.[…]You preserve water in times of flood and freshet to be used for power or for irrigation throughout the year. …” — 1913
3. •
   The discipline concerned with protection of biodiversity, the environment, and natural resources
4. •
   The protection and care of cultural heritage, including artwork and architecture, as well as historical and archaeological artifacts
5. •
   Genes and associated characteristics of biological organisms that are unchanged by evolution, for example similar or identical nucleic acid sequences or proteins in different species descended from a common ancestor
6. •
   lack of change in a measurable property of an isolated physical system (conservation of energy, mass, momentum, electric charge, subatomic particles, and fundamental symmetries)