The R-K Selection theory postulates that organisms reproduce using either R or K selected mechanisms and behaviors. When an organism is R selected, it will generally produce a lot of offspring and invest very little energy, if any at all, into rearing them. Due to the large amount of young, offspring are smaller at birth and thus less viable. Many will die before maturity, though since there are so many, the idea is that at least some will survive. When an organism is K selected, it produces fewer offspring throughout its lifetime and invests large amounts of energy into rearing them. These offspring will be larger and have a higher chance of living until maturity.
An example of a K selected organism is the spiney dogfish, a species of shark. Female dogfish are pregnant for 2 years and thus will reproduce quite slowly. Recently there has been concerns about the population of sharks. While dogfish are technically a threatened species, they are still susceptible to bycatching while fishing for other fish. This is especially bad considering that dogfish sexually segregate when not mating. That is to say, males and females will form separate schools. This means that when caught, either a large haul of females or males are being caught, which will further reduce the chance of successfully mating and producing offspring as the populations of either sex decreases.
Recent comments