Poikilosis is a recently introduced unifying theory in biology. It is based on the pervasive heterogeneity of all biological molecules, complexes, systems, networks, cells, organisms, and others. In a relaxed situation, such entities, called levels, are in an energetically favorable state called lagom. These states are maintained actively and passively by TARAR (tolerance, avoidance, repair, attenuation, resistance) countermeasures. Lagom is an emergent property that originates from multiple effects in a complex system. Lagom-changing effects include level extent changing processes, level conversion processes, level property changes, and temporal processes. When measuring, one should consider whether a system or entity has the lagom extent of heterogeneity, where there is a certain degree of variation, but where the measurements are equal and thus analyses should be based on intervals. Here, the concept of lagom is discussed and elaborated in biological systems, measurements, data analysis, prediction, and simulation. Special attention is given to the significance in medicine. Lagom reconstitution therapy can reduce the overall burden of diseases when curative care is not available. When a system has a non-lagom extent, the effect can spread due to the connectivity of levels. In extreme cases, such as comorbidities, there is a systemic effect, which can lead to the destruction of the system and death in the case of organisms. Consideration of lagom is essential to facilitate reliable studies and interpretations, as well as to enhance the reproducibility of experiments and studies.

Abstract The “hard problem” of the origin and nature of intelligence (cognition/“mind”) in the cosmos and its relation to symmetry and symmetry breaking goes back to the pre-Socratic Parmenides who claimed true reality (ontology) was a state of perfect symmetry and the world of change we know an illusion. Parmenides’s problem was that his ideal symmetry was broken ab initio by the cognitive act of him asserting it. This incommensurable separation of the time-asymmetric cognitive part of the world and physics came into modern science with Cartesian dualism and the time-symmetric equations of Newton and then with the measurement problem in quantum mechanics. The aporia is also found in the belief that unifying the forces of nature under a single symmetry would provide a “theory of everything” (TOE). Cosmology shows, however, it is symmetry breaking rather than symmetry that has brought the universe into being. Irreducible to the time-reversal symmetry of classical and quantum mechanics, an expanded thermodynamics, specifically the addition of the fourth law of thermodynamics, provides a universal explanation. Coupled with a first law time-translation symmetry account of information (in the meaningful sense) the origin and nature of cognition is readily seen as a direct manifestation of universal law rather than somehow sitting impossibly outside it.

Abstract All living systems need to regulate themselves and coordinate the activities of their parts to maintain themselves under changing conditions. Historically, homeostasis is one of the central ideas that have been employed to understand biological regulation. In this article we examine the application of the concept of homeostasis to medicine and its implications for understanding health. We argue that while using homeostasis to characterize health is in line with current criticisms of ideas of health as a complete state of well-being or absence of disease, such an endeavor has been hindered by the adoption of a narrow cybernetic interpretation of homeostasis based on feedback mechanisms and setpoints. This latter interpretation emphasizes stability and balance as the hallmarks of health: a stable physiological state that needs to be preserved or to which an organism needs to return after a perturbation, with change or imbalance as something to be counteracted. William Bechtel has contributed to criticizing this view and reframing the concept of homeostasis by focusing on the organism as a whole. By building on this work and looking at regulation beyond error correction as the organism’s ability to modify its internal dynamics in response to varying conditions, we apply this interpretation of homeostasis to health by advocating for a change of perspective: from a notion of health based on stability and balance to one based on adaptive change. We propose an alternative perspective that emphasizes the capability for change as a new lens through which to understand health.

Abstract Phenotypic plasticity has long been a phenomenon studied in evolutionary biology, but in recent decades it has attracted renewed interest among biologists. This interest has culminated in the so-called plasticity-led evolution hypothesis, according to which phenotypic plasticity, under certain circumstances, is capable of acting as an evolutionary factor, influencing the direction of adaptive change and promoting the emergence of new phenotypic variation. This article aims to analyze this hypothesis and the controversies it has generated and to bring more clarity to a debate that is often characterized by ambiguity and conceptual confusion. We will show how this debate can best be understood as a debate about the explanatory range of the two rival (but not mutually exclusive) models, plasticity-led evolution and mutation-led evolution, and their ability to explain the origin of phenotypic variation. We will then make use of Woodward’s account of causality in biology to assess the “specific weight” that the causes theorized by plasticity-led evolution can have within evolutionary explanations. To this end, we will analyze one of the best-known cases of plasticity-led evolution in nature, the North American spadefoot toad. Our analysis leads us to conclude that models based on plasticity-led evolution can be regarded as autonomous explanans, irreducible to the action of natural selection on preexisting genetic variation. This is due to the causal role played by environmental stimuli, which is accorded greater significance than in classical approaches. Furthermore, the plasticity-led evolution hypothesis could pave the way for a reassessment of the role of development in evolutionary processes.

Abstract American archaeology has long been focused on reconstructing past cultures through the description and chronological ordering of items found in the archaeological record. This goal was most evident starting in the early 20th century through what became known as culture history, which in retrospect produced results based on common sense and ethnographic analogues rather than on formal theory. By the mid-1930s, some culture historians realized the lack of testability in their conclusions and began exploring Darwinian evolutionary theory as an alternative. However, their efforts were often ignored or ridiculed, and it wasn’t until the early 1980s that evolutionary theory and associated methods began to play significant roles in archaeology. This acceptance grew from the development of a genetics-based theory of cultural transmission and the introduction of phylogenetic methods into anthropology and archaeology. These methods offered the necessary means for distinguishing between simple historical continuity—one thing following another chronologically—and heritable continuity—how one thing is related to another in terms of descent. Two concepts that play key roles in the reconstruction of cultural phylogenies are tradition and lineage, the former representing patterns of phylogenetic relationship and the latter patterns of genealogical descent.