Professor John H. Holland's (relatively) short book on how life forms on our planet came to be, and how they have adapted themselves to varying environments since the dawn of life itself is a masterful survey of the basic rules on the ways in which life forms are created, adapt themselves, and ultimately, are recycled into new life forms that propagate their species, or that make way for different life forms to emerge, propagate, and thrive. Much of what some people see as purposeful behavior is actually occurring randomly, but those random actions are constrained by the environment that co-evolves as time goes on. Everything is in motion once, and by sheer chance some things work out and get to renew themselves into either entities like themselves, or somewhat different depending upon what they encounter along their way through life.The hidden order that is common to all complex adaptive systems consist of particular and mechanisms by which they operate. The common properties include Aggregation, which has to do with identifying features common to all of them that they share in the aggregate (and excluding relevant detail), and the functionalities and purpose that they share in common; Nonlinearity, meaning that the values inherent in the system taken as a whole cannot be arrived at simply by adding the sum of the parts. What we are talking about is what happens when particular entities increase in scale. Your neighborhood grocery store bears no linear relationship to retail giants such as Walmart or Amazon, no matter what metric is used to describe and compare the differences. The third property common to all complex adaptive systems consists of Flows, which can be communications systems, logistical network, biological neural systems, biochemical messaging that cause the interacting entities to undergo precise transformations, and so on. As numerical density increases both on the plane of activity and on adjacent levels above and below that level, there are various effects that act as force multipliers that improve the efficiency, and hence, the survivability and effectiveness of those ongoing activities. Additionally, by reason of those increasing densities, there arise economies of scale and the ability of the entity to recycle and reuse waste materials, making those entities more productive. The fourth property is Diversity. Diversity appears as byproduct of different entities interacting with their environment, in competition with each other and forces within the internal and external environments. Research scientists have long noticed that as complex adaptive systems grow and develop, then display a capacity to self organize, displaying functionalities that could not have been predicted from an examination of their ancestor entities operating at a significantly more primitive level. That self organizing principle is evident everywhere, whether in nature, at the microscopic level, and everywhere within human society, and throughout the animal and plant kingdoms. These are inherent characteristics of all life forms.The mechanisms by which complex adaptive systems call us and progress share common mechanisms by which they operate. There is a process known as Tagging, which facilitates the formation of aggregates. These tags can be chemical, biological, visual, or some form of communication that signals to others both the capacity and availability to interact. A tag can be an amino acid, an electrochemical valence, a flag, a resume, or an email header. They all perform the same function. A second mechanism is Self-Similarity. All ants look alike, in the sense that they bear a family resemblance. Entities within a particular environment form hierarchies, typically pyramid in shape, and at each level within the pyramid, those of the top look like each other, those in the middle look like each other, those at the bottom looked like each other, and all those at the top and bottom may exhibit different behaviors, at a distance they appear indistinguishable from one another. In human reproduction, the female egg and the male sperm combined to form a single cell, which then rapidly grows and divides; and with each division the character and function of each of those stem cells has not lost their familial resemblance to one another, but different functionalities emerge. What we see is that each of those entities, whether stem cells, or organizational units within a functional hierarchy, exhibit certain behaviors appropriate to their station within the whole of that complex adaptive system, similar to, but not identical with, the behaviors observed at layers above and below the plane on which activity is taking place. Individuals become units; units become cohorts; cohorts coalesce into entities capable of executing executive functions, and so on. Just as bricks can be assembled into courses of masonry, biological cells self assemble into organisms; and organisms coalesce into colonies, and eventually into societies. Simple building blocks writ large. These are processes that are as common and ubiquitous as life itself on our planet, no matter how that life is expressed.Complexity science is one of the newer inhabitants of our intellectual universe. Much of what we know about complexity science comes as a byproduct of advances in computer science, which allows us to compress time and space in order to see how certain accumulations of knowledge, heretofore experienced as intuition and insights by researchers and philosophers, historians and others, are actually provable as tangible entities, each with its own character, but frequently sharing a mathematical model, or several of them, that cut across intellectual disciplines, and which give us insights into how the world really works. The living universe which we call life is a world in which constant competition and adaptation play themselves out in a wide array of life forms and circumstances. The competition and adaptation that we see at the molecular level in life is reflected in our politics, our economics, or social structures, and our ways of thinking about what we see around us, and try to make sense of it all.This is fundamental knowledge, and I highly recommend it to anyone. Better yet, read all three of the books that compose this triad: Emergence, From Chaos to Order, and Signals and Boundaries; Building Blocks for Complex Adaptive Systems. Having read all three, readers will come away with a solid base of knowledge, and most likely, a keen interest in complexity science, as did I.