The Dance of Eternity (5)
Stabilizing Selection vs. Directional Selection
Natural Selection is familiar to everyone. But for those of us who aren’t experts, the type of Natural Selection typically coming to mind is “Directional Selection.”
Natural Selection actually comprises two patterns: “Directional Selection” and “Stabilizing Selection.” In pre-Darwin era when it was believed that species were eternally unchanging, only Stabilizing Selection was recognized, though it wasn’t called by that name. Darwin’s greatness lies in his discovery of Directional Selection. While Directional Selection is dominant in our understanding of biological evolution today, in reality, Stabilizing Selection occurs more frequently.
Directional Selection
Directional Selection refers to the selection pressure that causes specific traits to change in a particular direction, promoting the survival and reproduction of individuals with those traits. This is observed when there is a significant environmental change or when a population moves to a new environment.
For example, in a colder climate, individuals with thick fur are at an advantage over those without. Over generations, thick-furred individuals increase in number, pushing out those with thin fur, leading to a population-wide shift towards thicker fur. Through Directional Selection, the distribution of traits within a population shifts in a specific direction, resulting in evolution.
Stabilizing Selection
On the other hand, Stabilizing Selection tends to suppress changes within a species, making it less noticeable than Directional Selection when discussing evolution, but it is just as important, or even more so. Stabilizing Selection removes extreme traits within a population, promoting the survival and reproduction of individuals with average traits. This is seen when specific environmental conditions remain stable for long periods. For instance, if birds with extremely large or small eggs have lower survival rates, birds that lay average-sized eggs are more likely to reproduce. Consequently, the trait of laying average-sized eggs becomes predominant, and the overall egg size in the population converges towards the average.
Stabilizing Selection reduces genetic diversity within a population by eliminating extreme samples that deviate from the average traits. Since the population is optimally adapted to specific environmental conditions, as long as these conditions remain unchanged, it maintains its advantageous state. However, big evolutionary changes happen less, and if the environment changes rapidly, the population’s adaptation to new conditions will be slower. In a sense, Stabilizing Selection catches a species in the trap of evolution.
It’s crucial to understand that while Stabilizing Selection may appear static, it is continuously undergoing a competition between “selection pushing away from the average” and “selection converging towards the average.” The predominance of the latter results in the population maintaining a seemingly unchanged average state. It is not a fixed, unchanging structure but exists in a state of microscopic fluctuations.
Both Directional and Stabilizing Selection are types of “selection” after all, which implies the existence of multiple options from which to choose. This is true for stabilizing selection as well, where the existence of multiple options leads to a selection process, ultimately resulting in stabilization by chance.
Dynamic Equilibrium
Thus, before considering the implications of stabilizing selection for corporate management, it’s worth digging into the true nature of Stabilizing Selection. There’s a concept I love: Dynamic Equilibrium.
This animation dramatically illustrates that even organisms appearing structurally stable from a distance are, in fact, constantly subjected to the flow of elements in and out, barely maintaining equilibrium. This animation embodies the concept of “Dynamic Equilibrium” proposed by Japanese biologist Shinichi Fukuoka, representing the metabolism of individual organisms. Although it operates on a different level from biological evolution, it offers significant insights when considering Stabilizing Selection.
Stabilizing Selection implies that a species is not a robust, unchanging structure but maintains stability as a result of a delicate balance between “convergence to the average” and “divergence from the average.” The same applies to companies, where organizational structures are constantly subjected to fluctuations but do not change easily. Here, the mechanism of “selection promoting stabilization” prevails over “selection promoting change.”
“Stable” Company?
When we think of stable and robust corporate organizations, what image comes to your mind? Perhaps something like this:
This image fails to evoke the process of “constantly generating multiple options and selecting from them.” Instead, it often conjures rigid notions like acquiring personnel that fit the organization, logical decision-making procedures, and robust security and compliance procedures. However, in reality, there’s a balance between “forces pushing for change” and “forces trying to suppress it,” with the latter prevailing, leading to stabilizing selection.
Next, let’s consider what factors drive “stabilizing selection” and “directional selection” in biological evolution, and what implications these factors might have, if applied to corporate organizations.
