Which characteristic of living things is essential for the survival of a species over time?

Reproduction is the characteristic of living things that is essential for the survival of a species over time. Through reproduction, organisms create offspring, ensuring the continuation of genetic material and the species itself across generations. This process not only allows for the propagation of a given species but also introduces genetic variability, which is crucial for adaptation and evolution in response to changing environments. While growth, order, and energy processing are important characteristics of living organisms, they do not directly contribute to the survival of a species as effectively as reproduction does. Growth relates to the development of an individual organism, order pertains to the complex organization of living systems, and energy processing involves how organisms take in and convert energy for their life processes, but none of these will ensure the existence of a species without reproduction.