The germination of the new biology arose gradually from the study of strategy ecology (life-history strategy and behavioral strategy). Strategy ecology attaches importance to finding an analytic and calculative tool capable of producing some prediction on the principle of evolutionist framework. When some of the analytical methods of economics are introduced to the calculative prediction of life-history variation and behavioral ecological variation, life-history ecology study and behavioral ecology study begin to be able to give a sound explanation of adaptation, and this is an important development in modern ecological studies. At the same time, this process makes an excellent opportunity for intraspecific comparison to develop. Although they are two research directions in nature, in the history of science, it is usual for a new developmental direction to borrow ideas and methods from another more successful research direction.
Therefore, neo-adaptationistic biology germinates by borrowing strategy ecology's concepts, principle, and analytic method at the beginning. This is done by directly applying the theory and calculation of interspecific comparison of life-history strategy and behavioral strategy to intraspecific comparison. Therefore, in a sense, at the first important developmental stage of the new biology, bionomic strategy theory is accepted completely and is applied to the intraspecific comparison. During this period there is no new concept being generated.
Of course, this kind of overall acquisition has a downside. On the one hand, strategy ecology basically does not involve knowledge of physiology. That is to say, researchers of strategy ecology are not interested in physiological problem at the beginning, and the study of bionomic strategy has not been able to associate with physiology, especially the latest microphysiological knowledge, to improve and develop its theoretical system.
On the other hand, the analytic and calculative method of strategy ecology is copied from mathematics or economic mathematics at the beginning, and the analytic method is not a substantively reductive paradigm, consequently it would not be able to develop into a substantively reductive biological theory if it was limited to the theory and calculative model of bionomic strategy. In other words, this kind of analysis and language expression cannot be integrated with the existing biological language system. In fact, using this kind of analysis, intraspecific comparative study has found many important physiological phenomena which were new to this field. Moreover, these discoveries need to be integrated into the basic physiological theory, but a language barrier is in the way and hinders the development of a new physiological theory. This is another disadvantageous aspect.
Therefore, at the first developmental stage of adaptational biology, strategy ecology has made a commendable contribution. But these concepts and principles need to go through a materialization process to be transformed into reductionistic biological expression. They are important components of the neo-adaptationistic theory, including such concepts and principles as trade-off, strategy, optimization, evolutionary stable strategy, ecological niche, bionomic strategy, life-history strategy, optimum adaptation, behavioral strategy, reproductive strategy, optimal foraging strategy, cost and benefit, resource competition, strategy game theory etc.
Let's look at the second developmental stage of the new biological theory. That is a development at the borderland between physiology and ecology. Physiological study of micro process is often required to be related to ecological and adaptive variation, and it may gradually move toward this new direction unconsciously. In particular, physiological study always has a focus on an individual organism, and it must pay attention to an individual's physiological variations in different environmental conditions. Consequently it may unconsciously move toward intraspecific physiological comparison. This is an unexpected but satisfactory result.
Many disciplines have comparative studies of physiological adaptive variation, including detoxification physiology, disease resistance physiology, stress physiology, allelopathy physiology, symbiotic physiology, compensatory physiology, allergic physiology, immune physiology, metamorphic physiology, emotional physiology, group information control physiology, and so on. Experimental studies of these areas have contributed something to the burgeoning and development of adaptational biology. The rapid growth of microbiological knowledge enables the experiments and theoretical analysis of the above-mentioned disciplines to reach an extent that is at reductionistic molecular level and population adaptation level simultaneously. These studies are so intertwined together that we could not imagine how the previous traditional physiology or ecology would reach this extent of integration alone.
In studies of the above-mentioned disciplines, physiological theory of adaptational biology gradually concentrates on two aspects: stress resistance theory and plasticity theory. Stress resistance theory sees environmental factors which are disadvantageous to the organism's normal life, such as hazardous chemicals, high temperature, excessive moisture, high radiation, or harmful life-form or microorganism, as stressors to the organism. Stress resistance theory sees organism's physiologically created and protective changes under stress as countermeasures taken by the organism, e.g., regulation of inner chemical synthesis and decomposition, compensation of physiological functions, producing of immunity and antibody, enhancement and decrease of internal organ's function, changes in hormone, regulation of blood distribution, changes in energy supply, and so forth.
Stress resistance theory suggests that organisms may have a variety of defenses. At different growth stages or when being affected by different stressors, organisms' defenses may vary. There is a physiological mechanism within organisms regulating the manner of self-defense. This mechanism can operate at various levels including system, organs, tissues, cells, and molecular level. Adversity physioecology generalizes them with concepts as strain, stress resistance etc. Pathophysiology summarizes them with notions of anti-injury and compensation. Both definitions refer to the same meaning, but because they belong to different disciplines, they are termed differently. In other words, evolutionary pathophysiology is a broad adversity physioecology, and the adversity physioecology is a broad evolutionary pathophysiology.
We can see that in its second developmental stage, adaptational concept and language begins to break away from the initial status when it borrowed terms from strategy ecology. Now its terms are characterized with basic biological language¡ªdescribing character and analyzing reductionistically based on the current microphysiological experimental study and bearing a strong color of substantiality theory. This development combines adaptation, ecology, physiology, and especially microphysiology together. Therefore, adaptational concept and language should not be understood simply from a perspective of quantitative analysis of bionomic strategy; instead, it should be re-appreciated with a substantive nature of physiological bionomic strategy in view.
The phenotypic plasticity theory is even more important theoretically because it represents two important breakthroughs in intraspecific comparison, one of which is to negate theoretically the traditional view of a fixed genotype determining a fixed phenotype. This change of view marks that the new biology has broken away from the original gene-phenotype theory, and has begun to move toward a new direction of gene-strategy-phenotype theory.
The second breakthrough is that the term phenotypic plasticity has covered almost every aspect from bionomic strategy to plasticity and compensation relating to life-history, behavior, character, reproduction, sex, development, molecule, cell, metabolism, structure, and internal organs. This means that various forms of physiological adaptive modulations have already gathered together. Previously, traditional biotic diversity study only involved interspecific comparison, but it has now been extended to a level of intraspecific comparison of phenotypic diversity. Organisms with the same genotype in their lifetime may actively make a variety of alterations in their physiological phenotypes in response to environmental change. This new concept has increasingly been taken or seriously accepted. This theoretical development is very important because it is on the path to completely integrating physiology with ecology.
Plasticity study has coined many new concepts such as adaptive flexibility, phenotypic fine-tuning, ecological development, dynamic plasticity, ontogenetic contingency, sensitive periods in development, facultative development, fixed organisms, plastic organisms, plastic response, ecological generalist, highly plastic genotype, adaptive diversification, generalist phenotype, stress-tolerance strategy, and facultative adaptation. These languages have a high degree of independence, and can be easily associated with intraspecific experimental comparative study. From these concepts we can see that the original mathematical language has been replaced with substantive terms, and the useful strategy thinking which describes physical things has been inherited. Therefore, it has begun moving toward an independent and specific theoretical direction.