Energy
What does the survival of a living organism depend on?
Biology
Survival rate Biological interaction Predation 13 Things That Don't Make Sense Balancing selection
Survival_rate-Net_survival_rate Biological_interaction-Commensalism Predation-Population_dynamics 13_Things_That_Don't_Make_Sense-Chapter_10 Balancing_selection-Selection_acts_at_different_levels
When someone is interested in how survival is affected by the disease, there is also the net survival rate, which filters out the effect of mortality from other causes than the disease. The two main ways to calculate net survival are relative survival and cause-specific survival or disease-specific survival. Relative survival has the advantage that it does not depend on accuracy of the reported cause of death; cause specific survival has the advantage that it does not depend on the ability to find a similar population of people without the disease. 
Commensalism benefits one organism and the other organism is neither benefited nor harmed. It occurs when one organism takes benefits by interacting with another organism by which the host organism is not affected. A good example is a remora living with a shark. Remoras eat leftover food from the shark. The shark is not affected in the process, as remoras eat only leftover food of the shark, which does not deplete the shark's resources. 
It is fairly clear that predators tend to lower the survival and fecundity of their prey, but on a higher level of organization, populations of predator and prey species also interact. It is obvious that predators depend on prey for survival, and this is reflected in predator populations being affected by changes in prey populations. It is not so obvious, however, that predators affect prey populations. Eating a prey organism may simply make room for another if the prey population is approaching its carrying capacity. The population dynamics of predator-prey interactions can be modelled using the Lotka–Volterra equations. These provide a mathematical model for the cycling of predator and prey populations. Predators tend to select young, weak, and ill individuals. 
Sex. This chapter is a discussion of theories of the evolution of sexual reproduction. The common-sense explanation is that although asexual reproduction is much easier and more efficient for an organism it is less common than sexual reproduction because having two parents allows species to adapt and evolve more easily to survive in changing environments. Brooks discusses efforts to prove this by laboratory experiment and goes on to discuss alternative theories including the work of Joan Roughgarden of Stanford University who proposes that sexual reproduction, rather than being driven by Charles Darwin's sexual selection in individuals is a mechanism for the survival of social groupings, which most higher species depend on for survival. 
The fitness of a genotype may depend on the fitness of other genotypes in the population: this covers many natural situations where the best thing to do (from the point of view of survival and reproduction) depends on what other members of the population are doing at the time. 