Meaning
First, what does r and K mean? Both of these terms are derived from the Verhulst model of population dynamics: dN/dt=rN(1-N/K) in which r is the maximum growth rate of the population (N) and K is the carrying capacity of the environment, also the notion dN/dt means the derivative of N with respect to t (time) (1). The terminology of r/K-selection was first coined by ecologists Robert MacArthur and E. …show more content…
Some animals are on the extreme ends of the spectrum but there are some that are in the middle of the spectrum, like how birds are not big but have K-selected characteristics (8). Trees have both r and K strategies in which they have very long life spans but they also in reproduction use techniques that many r-selective species use (Figure 3). Some express this spectrum by comparing it to economic terms. They go about this comparison by saying that r vs K is a process of discounted future returns (10). In which r-selection is similar to heavy discounts while K-selections is similar to light discounts (10). K-selection is similar to if you were to invest your money into a CD and r selection is if you decided to diversify in the stock market. The stock market is more volatile but could yield more rewards but a CD is stable and you know you will get your rewards in the future. If this concept is applied to the spectrum, then organisms like the sea turtle, which exhibit both r and K, are splitting their money and putting them into the stock market and a CD (Figure 4). This depends on what place an animal is on the spectrum of r vs