| R and K Strategies Each species on the earth employs a different strategy to ensure that they leave offspring behind before they die. This strategy is usually reinforced by the organism’s genes and so it is difficult for most organisms to deviate much from their inherited strategy. There are two fundamental types of reproductive strategies and they can be described as antagonistic – meaning that when you are reliant on one you normally use less of the other. These two strategies are the K strategy and the r strategy. K strategists are often said to be “K- selected” and r strategists are said to be “r-selected.” Biologists often refer to a “spectrum” or continuum that helps us distinguish one organism’s reproductive strategy from another. All living organisms are supposed to fall somewhere on this continuum between the two extremes (r and K). Also, organisms can be differentiated from one another in terms of their relative reliance on one strategy over the other. r ____._________._________.______.________.__________._________._________._______.____ K bacteria mollusks insects fish amphibians reptiles mammals apes humans R strategists usually create an abundance of offspring in the hopes that a few will make it. These species usually have a very short maturation time, often breed at a very young age, have a short lifespan, produce many offspring very quickly, have young with high mortality rates and invest relatively little in parental care. The parents do not focus on passing down memes, units of cultural information, to their young. Instead the behavior of the young is determined by their genes. The young are precocial, meaning that they often can make it on their own without any instruction from their parents. Examples of r-selected species include bacteria, insects, and fish. K strategists are very different in that they attempt to ensure the survival of their offspring by investing time in them, instead of investing in lots of them. It is a reproductive strategy that focuses on quality over quantity. K strategist have relatively few offspring and make an effort at being good parents. Their young are altricial meaning that they cannot survive on their own until they reach adulthood. This extended period of maturation is used for memetic transference- the parents teach the young so that they can go on to reproduce themselves. K strategists are known to have a relatively long life span, produce relatively few offspring, the offspring have low mortality rates and the parents provide extensive parental care. The offspring are also relatively intelligent so that they can internalize the lessons from their parents. K-selected species include elephants, apes and whales. Humans are perhaps the most K-selected because their young are truly helpless- they necessitate a full two decades of parental care and tutelage and the parents usually only produce one offspring at a time. An organism’s behavior determines its chances for reproductive success and therefore the rstrategy is by far the more robust strategy. The behavior of an r strategist is dictated by its genes which are naturally selected over geological time. This means that r strategists are self sufficient and their behavior rarely goes wrong. The behavior of a K strategist on the other hand is completely dependent on the lessons from its parents and so extreme K strategy is very risky. I believe that there are certain mechanisms that might help mitigate the risk inherent in the K strategy. To read my theory on cognitive impairment and meme utility click here. Altrical: adj. The condition of being helpless or dependent on external support. Dependent on parents for food. Meme: noun A unit of cultural or social information that is transmitted by behavior or by observation. A lesson that is transmitted from one mind to another. Precocial: adj. The condition of being self sufficient or independent. Capable of walking shortly after birth and of leaving the nest within a few days. |
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