Rick Stevens, Shinrin Yoku, 48″
X48″ oil on canvas




The INTEGRATIVE BIOLOGY of BEHAVIOR involves the coordinated activities of four broad areas:




ECOLOGY is concerned with the ABIOTIC  and BIOTIC environment into  which an individual or group changes is born with must meet its biological NEEDS

All the processes we categorize mainly as Development, Evolution, or Physiology occur in response to an environment that is more or less stable, but never static.    

For example, At the cellular level of organization, development involves the progressive specialization or tuning of specific lineages of cells that begin with a single cell.  Differentiation occurs as a result of activation of genes which operate in their respective microniches.  Cells, like organisms, exist in an ecosystem in which they represent the best adapted form possible given their intrinsic possibilities and the resources available to support them. Fuchs & Blau (2020)[i] call them “architects of their own niches.”  Their development—in which they manifest specialized structure and function to enable optimal accommodation depends on their local niches… but as they proliferate, they change the niche and those changes then feed back to affect further proliferation. 

Ecosystem dynamics aredetecatble in the interactions of the diversity of players from viruses, though bacteria — the now well-known microbiome: our load of organisms within us, the products of which play a significant role in our physiology–metabolism, health, and behavior

[i] Tissue Stem Cells: Architects of Their Niches   Elaine Fuchs1,* and Helen M. Blau   Cell Stem Cell. Author manuscript; available in PMC 2021 Feb 4. Published in final edited form as: Cell Stem Cell. 2020 Oct 1; 27(4): 532–556.  doi: 10.1016/j.stem.2020.09.011


  • Billions of cells are lost daily from our body’s tissues, which are in a perpetual state of flux throughout our lifetime. The molecular engines that drive this turnover are self-renewing tissue stem cells. The work horses are stem cell-generated, short-lived progenitors that balance proliferation and differentiation, thereby maintaining tissue homeostasis. The homeostatic requirements for cellular replacements are tissue and context specific. They are continual in blood, epidermis, and intestine, episodic in the hair follicle and lactating mammary gland, and limited in brain and muscle. However, even largely quiescent stem cells, such as those of the muscle, can be mobilized into action when their tissue is injured. To guard against infection and heal wounds, the normal homeostatic cues—termed the “milieu interieur” in 1865 by Claude Bernard—must be overridden in ways that are still being determined.
  • Understanding stem cell behaviors necessitates knowledge of their local environment or “niche.” Increasing evidence shows that whether quiescent or active, stem cells are not simple passive responders to their niches; rather, they play an integral role in creating and communicating with their niches that envelope them. Regenerative signals, emanating either from a build up in crosstalk with niche factors or from marked environmental changes upon injury, alter stem cell behavior and disrupt the homeostatic equilibrium of the tissue. In part, the stem cells’ own progenies can become important niche components: while early short-lived progenitors can send transient activating cues back to their stem cell parents to fuel their self-renewal and boost tissue growth (Blau et al., 2015Hsu et al., 2014Mondal et al., 2014Porpiglia et al., 2017), differentiated progeny can home back to their niche to halt further proliferation and tissue regeneration and restore homeostasis (Montarras et al., 2005Sato et al., 2011Yu and Scadden, 2016). In this way, tissue regeneration is orchestrated by a delicate balance of temporally coordinated cellular interactions and molecular feedback circuits in which stem cells play a central role.
  • Heterologous stem cell niche components include the basement membrane, rich in extracellular matrix and stem cell growth factors, as well as blood vessels, lymphatic capillaries, nerves, stromal, adipose, and a variety of tissue-resident immune cells that function with stem cells to guard against tissue damage and pathogens. The beauty of having immune cells as integral constituents of stem cell niches is that many are mobile, able to migrate to local lymph nodes and stimulate non-resident immune cells, which can then travel through the circulation to the site of tissue damage and contribute to the inflammatory response that clears pathogens and damaged cells from the tissue (Fan and Rudensky, 2016). Reinstating homeostasis, however, relies upon tissue repair, which is incompatible with inflammation. Since the stem cells are responsible for the reparative phase of the response, there must be intricate immune-stem cell communication to ensure not only that the pathogen invasion is under control, but also that the inflammation is subsequently dampened in order to facilitate repair (Arnold et al., 2007Burzyn et al., 2013Fan and Rudensky, 2016). How this happens is still largely a mystery, but a few clues are beginning to emerge.
  • Here we review how stem cells serve as architects of their own niche. This microenvironment envelops the stem cell and dictates its function during homeostasis while allowing it to rapidly mobilize its tissue regenerating energies when an injury occurs. We focus on two markedly different tissues—the skin epithelium and the skeletal muscle—both of which are subjected to stress and damage throughout life. We highlight features of the stem cells and their niches and discuss how they combine context-specific and universal mechanisms to maintain tissue fitness. We discuss increasing evidence that tissue stem cells sense and communicate with an amazingly diverse array of niche components. As we are beginning to learn, this complexity enables stem cells to not only deflect minor insults and maintain homeostasis, but also remain poised to sense and respond to natural regenerative stimuli and to the diverse array of tissue damage and other stresses they encounter throughout their lifetime. Given the complexity of stem cell niches, it is also perhaps not surprising that across many different tissues, including muscle and skin, aging often involves a breakdown of extrinsic niche components, rather than the intrinsic self-renewal capacity of its stem cell residents (Blau et al., 2015Ge et al., 2020Pentinmikko et al., 2019Raaijmakers, 2019Segel et al., 2019Tierney and Sacco, 2016). An additional consequence of aging-associated changes is an increase in tissue stiffness that can disrupt homeostatic stem cell mechanosensing (Cosgrove et al., 2014Gilbert et al., 2010Madl et al., 2018).
Although all domains of DEEP ETHOLOGY manifest extensive interconnectedness, it is, for most of us, more apparent in the web of life described in ECOLOGY.   The ENVIRONMENT in which all organisms find themselves must–in the course of natural selection–provide for all biological needs, and all organisms compete for limited resources to meet those needs. (Whatever resource(s) might be in shortest supply is termed “selection pressure.”  The flexibility of an individual (or species) in coping with these pressures results in different patterns: sexual selection (selection pressure if “female choice”), ecological selection, stabilizing selection, disruptive selection and directional selection, each describing the patterns of successful coping with pressure.

So, the environment affects every level of organization: EVERYTHING, no matter how minutely described or defined, seem to have other things with which it is more-or-less intimately related–which (in a way) define it.   An interesting cascade of connections has been described in detail only in the past few decades: environmental variables affect the activity of GENES –the process is termed EPIGENESIS [see the DEEP ETHOLOGY GLOSSARY entry for EPIGENESIS ].

[we will revisit selection pressure relative to biological NEEDS when visiting PHYSIOLOGY:  the first response of individuals to the real or perceived or even threatened inability to meet a biological need evokes a STRESS RESPONSE.]


An aside about TRAITS:  The organism possesses millions of trait, hierarchically organized and more-or-less interconnected.  They are the “manifest morphological or behavioral attributes of an organism.” A trait can be observed, described, and defined at every level of organization from the biochemical and physiological to social and biomic.   As a variable attribute in the life of the organism, it presents itself to the vagaries of the environment–directly or indirectly–and its success in coping–that is enabling the organism to meet its biological NEEDS in a given environment–will determine the fate of the organism,  See the DEEP ETHOLOGY GLOSSARY entry for TRAITS 




Metaphysical implications??

Every living thing is a sort of imperialist, seeking to transform as much as possible of its environment into itself… When we compare the (present) human population of the globe with… that of former times, we see that “chemical imperialism” has been… the main end to which human intelligence has been devoted.  (Bertrand Russell, 1960)