ZOOM 05: A&O for Katie at Home


for Katie


(change between generations)



(…of traits that evolved unusually quickly because they provided a competitive edge in securing reproductive partners). 

(AND exemplify how very prominent traits may have had very modest beginnings)

The INTEGRATIVE BIOLOGY of BEHAVIOR involves the coordinated activities of four broad areas (as biologists study them): DEVELOPMENT, ECOLOGY, EVOLUTION, and PHYSIOLOGY and how they are brought to bear on BEHAVIOR (“DEEP ETHOLOGY”





































EVOLUTIONARY BIOLOGY is concerned with changes in behavior across the generations by means of genes and/or memes.  The process of “ritualization” in particular is relatively rapid evolution, often under the intense form of natural selection the includes mate choice: “sexual selection.”     








































ADAPTATION (the process) 

Adaptation is . . .   “The processes by which organisms or groups of organisms maintain homeostasis in and among themselves in the face of both short-term environmental  fluctuations and long-term changes in the composition and structure of their environments.”  (Rappaport, 1971)   (homeostasis refers to stability of (mostly) internal processes that are essential for life; they are maintained by a dynamic balance of the multiple interacting systems that operate in an organism.) (see A&O Glossary)


The ESSENCE of “EVOLUTION” then, is that biologically relevant information is transmitted from one generation to the next.

FITNESS (direct, indirect, inclusive)  

The extent to which an individual contributes to subsequent generations is is manifested through its phenotype—the corporeal, manifest expression of gene activity.  It is profoundly affected by the environment at all stages of development—that is, “the fitness of a given phenotype can also be different in different selective environments.”     (Wikipedia on Fitness). 

to subsequent generations is is manifested through its phenotype—the corporeal, manifest expression of gene activity.  It is profoundly affected by the environment at all stages of development—that is, “the fitness of a given phenotype can also be different in different selective environments.”     (Wikipedia on Fitness). 


.”  (Rappaport, 1971)   (homeostasis refers to stability of (mostly) internal processes that are essential for life; they are maintained by a dynamic balance of the multiple interacting systems that operate in an organism.) (see A&O Glossary)






key observations that could be made by any naturalist … and their inferences

  • OVERPRODUCTION [individuals tend to produce as many offspring as possible]
  • STABILITY [population size seems to remain stable from generation to generation in stable environments]
  • LIMITED RESOURCES [there is not enough for everyone] (ANY RESOURCE that is limited (food, sunlight, shelter, reproductive partners,…) can be regarded as a SELECTION PRESSURE)
  • inference is “COMPETITION” –a struggle for existence
  • VARIABILITY [offspring manifest varying traits]
  • HERITABILITY [traits are to some extent inherited]
  • inference is “DIFFERENTIAL SURVIVAL” (essence of natural selection)[some traits allow their bearers to produce more offspring than other individuals = be more fit]
  • inference is “EVOLUTION” Over many generations, differential survival leads to changes in the frequencies of genes and thus the traits they influence.


SEXUAL SELECTION” IS a “special case” of natural selection. Sexual selection acts on an organism’s ability to obtain (often by any means necessary!) or successfully copulate with a mate” (Evolution 101, Berkeley)  REPRODUCTIVE partner is the SELECTION PRESSURE.


SELECTION PRESSURE can be exerted by any elements of the developmental environment with which an organism must cope to fully express its latent potential in a way that enhances FITNESS. It can affect the organism at any stage in development.























COURTSHIP involves COMMUNICATIONS that “signal” reproductive status (available as a partner–or not; competence to care for partner or offspring).  Like all communications, it occurs  between individuals involves “the transmission of a signal from one animal to another such that the sender benefits, on average, from the response of the recipient” (Slater (1983) in D&DVM4; chap. 12 p. 210).  Signals can be static (e.g., a continually visible change in body color) or dynamic (a controllable exposure of a signal such as body color)  more on the DEEP ethology of communications


In courtship it is common for the signals of one sex to evoke hormonal changes in the other such that behavior is affected.   























The EVOLUTION OF COMMUNICATION provides particularly vivid examples of how traits can be transformed to serve alternative purposes . . . it is exemplary also of the ingenuity of the organism in finding traits that can be employed in improving fitness or coping with new challenges — its expression of bricolage, the adapting of a “tool” (trait) devised to serve one need to solve some other need, emphasizing the utilization of whatever traits might be available.  (Understood sometimes by analogy to the television action character, MacGyver, who regularly solves complex problems by adapting ordinary objects to the task in ingenious ways; a bricoleur (a handyman good at using whatever materials are available)



A communicative signal can be derived  from any attribute of an animal upon which natural selection can act—behavioral, physiological, developmental, or  morphological traits—and which can be detected by other individuals.  Traits often serve multiple functions, most of which may be incidental to the adaptive problem it evolved to solve.

  • In ritualization, one of those incidental behavioral patterns that also represents the state of the animal that may be detected manifests it in a way that it also  becomes a more effective or efficient in communicating.  For example, a motor pattern reflecting a homeostatic adjustment to changes in ambient temperature (e.g. feather fluffing to retain heat in a cold atmosphere) may also function as a signal that the actor is under mild stress. If it might be adaptive to communicate the underlying stress response, exaggeration of some specific aspect (size or shape of feathers) would improve its communicative function. 


The key attribute of the trait is that it conveys information, usually about one individual to another.  This information then makes the world of the recipient more predictable, less chaotic.      Behavioral traits that have given rise to displays have been identified  by Hinde and Tinbergen (1958) and Morris (1956).


BEHAVIOR that can act as a SIGNAL:

The primary somatic  responses are:

1.  Intention movements (such as adjustments in posture to facilitate subsequent motor pattern)

2.  Perseverance (animal attempts to continue behaving despite obstruction  or absence of releasing stimuli)

3.  “Snap decision” (animal responds quickly to only one element of a  stimulus situation)

4.  Ambivalent posture (animal experiences simultaneous arousal of  incompatible tendencies)

5.  Alternating ambivalent movements (successive expressions of  incompatible tendencies)


Secondary somatic responses are:

1.  Displacement activities (associated with conflicting motivations: animal expresses component of inappropriate  behavior pattern)

2.  Redirection activities (an appropriate motor pattern is expressed but  redirected to an inappropriate target)

3.  Regressive activities (frustrated animal “falls back” on earlier  behavioral patterns; espec. in laboratory)

4.  “Neurotic” inactivity (animal ceases to respond; Seligman’s “learned  helplessness (?))



OF SPECIAL INTEREST are sources of displays are autonomic responses which have an external expression  (Morris 1956).  Many of these have an affect or stress-related proximate causation:       

1. Alimentary:  Increase or decrease in salivation.  Sphincter control,  urination, defecation.  (e.g., territorial marking)

2. Circulatory:  Pallor, flushing, vasodilation of sex organs.  Fainting.(e.g., skin patches)

3. Respiratory:  Changes in respiratory rate or amplitude.  Gasping,  sighing, panting.  (e.g., inflation displays, hissing, speech (?))

4. Thermoregulatory:  Sweating, pilomotor responses.  (e.g., hair or  feather erection, scent signals) Electrodermal response  (see FRISSON)

5. Lacrimatory:  weeping.

   6. Altered sensory system                             




Ways in which the displays can become elaborated  (based on Morris  1966):

1.  Development of conspicuous structures  (enlarged tail feathers, dewlap, antlers)

2.  Schematization (“simplification”) by means of (for example)

    • Lowering of threshold changes in absolute and relative thresholds of components) (hormones can affect thresholds)
    • Rhythmic repetition
    • Exaggeration of certain components of the movement
    • “Freezing” of movements
    • Change in vigor.


  • Language?  In humans, the hyoid apparatus is important in verbal communicating (see The Origin of Speech, below) … interestingly some of the neural connections controlling the cartilage and bone of this anatomical innovation are autonomic, and can be activated in anticipation of stressors that will call for increased respiration[i]to support increased metabolism in coping with an urgent challenge such as defense, aggression, courtship. The hyoid in fish: gill flaps of fish speed up to increase water flow and thus more oxygen exchange.  Can the hyoid affect the nervous movements of a man’s adam’s apple?  The “adam’s apple jump” is associated with anxiety[ii]
  • Frisson. An interesting example for Art & Organism is that of frisson –a “thrill” signal (often associated with elevated hair, or a chill) likely derived from stress-related responses such as coping with (or anticipating) the thermoregulatory challenges that attend fight-or-flight.   Many autonomic responses seem to play into specific ritualized behavioral patterns (alimentary, circulatory, respiratory, and thermoregulatory; see list from Morris 1956, in ritualization notes).  


“Looking for an evolutionary based rationale of emotional piloerection, one might also speculate that the ambivalent experience of being moved or touched in response to the sublime may involve feelings of vulnerability or even imminence (Keltner and Haidt, 2003 ;  Konečni, 2005). In animals, erection of body hair is known as a mechanism, which makes them appear larger and stronger, and which is applied in situations of imminence (Darwin, 1872, p. 87) as well as in the course of courtship (e.g., Nishida, 1997). According to this notion, emotional piloerection in humans could also be viewed as an evolutionary relic corresponding to a response to the threatening aspect of being moved or touched.” (EXCERPT from DISCUSSION of Benedek and Kaernbach (2011) article on piloerection and affect)




[i]  The U-shaped hyoid bone, located just under the chin, is an important contributor to both respiratory and digestive processes. The hyoid is attached to the tongue, and helps you to swallow at the start of digestion. In the respiratory system, structures that produce sound depend on the hyoid. The body and the greater horns of the bone serve as attachment points for neck muscles that raise and lower the larynx during speech (as well as during swallowing). ( https://www.visiblebody.com/learn/respiratory/upper-respiratory-system )

[ii] ADAM’S-APPLE-JUMP “is 1. A conspicuous up-and-down motion of the Adam’s apple. 2. A movement of the throat visible while gulping or swallowing, as in nervousness. … and an unconscious sign of emotional anxiety, embarrassment, or stress. … Unconscious and uncontrollable, it gives an exquisite look into the sympathetic (fight-or-flight) division of the autonomic nervous system.” (RESEARCH REPORTS1. Swallowing “associates well with flight and submission” (Grant 1969:528). 2. Stimulating the emotionally sensitive amygdala can cause involuntary body movements “associated with olfaction and eating, such as licking, chewing, and swallowing” (Guyton 1996:758-59). 3. The founder of kinesics, Ray Birdwhistell, included an entry for “Adams Apple Jump” (without defining or explaining the term) on p. 2 of his 1952 book Introduction to Kinesics. … Anatomy. Anxiety, social discomfort (e.g., embarrassment), and fear are often visible in unwitting, vertical movements of a projection at the front of the throat called the laryngeal prominence, where the largest (or thyroid) cartilage of the Adam’s apple shows, prominently in men, but less noticeably in women. Neuro-notes. Acting through the vagus nerve (cranial X), emotional tension from the brain’s limbic system causes unconscious muscular contractions of  the sternothyroidthyrohyoid, and associated inferior pharyngeal constrictormuscles of the Adam’s apple. Movement is evident as the muscles contract to swallow, to throat-clear, or to vocalize an objection which may be left unsaid. The Adam’s apple is emotionally responsive (i.e., reflects visceral or “gut” feelings) because its muscles are mediated by the vagus nerve, one of five cranial special visceral nerves.



Evolution & Physiology.  The few dozen categories of primate vocalizations (Passingham 1982 in Merlin. 1991) are all expressed in emotional or manipulative contexts: most control appears to be limbic or cingulate gyrus (so-called “limbic” speech, see Sutton and Jurgens 1988 in Donald  1991:183).  Donald (1991) believes that bringing vocalization under voluntary control is an adaptation for voluntary control of emotional responses (recalls ritualization).  And see pulvinar and its thalamic role: Pulvinar (posterior part of dorsal thalamus; afferents include lateral and medial geniculate and superior colliculus; efferents include cortex, parastriate, posterior parietal, posterior temporal, and frontal; projects to subarachnoid space; lots of synapses converge on a single  departing dendrite;.  Tectum projects (back to) the cerebral cortex through pulvinar;  typical ascribed function is visual-auditory association; it increases dramatically in size in primates along with ascending input from the superior colliculus  –consciousness may involve thalamus as much as cortex (p. 476)




Ritualization and Human Neurobiology


The term “ritualization” was employed after Huxley (1914) noted similarities between animal courtship displays and some human behavioral   patterns.  The possible fusion of genetic and cultural factors in giving rise to a display is accommodated in Smith’s (1979) definition:

 … ritual connotes, at least, behavior that is formally  organized into repeatable patterns the basic function of  which is to facilitate interactions between individuals,  between an individual and his deity, or between an individual  and himself across a span of time.


Famous scholars in the social sciences (e.g., Clyde Kluckhohn) have suggested that human ritual behavior reduces anxiety –that it can be (what a physician would call) “anxiolytic.”  This effect on health likely contributes in some way to fitness.  Ritual also synchronizes the activity of participants, a phenomenon that contributes to group cohesion –which can also contribute to fitness.


“Ritualization” leads to consistency in expression, also sometimes referred to as “stereotyped.”  This always refers to a pattern of behavior that is highly consistent in form whenever it is expressed –BUT, in the clinic, it also often refers to dysfunctional repetition–A “stereotypy.”  –That is, a compulsive repetition of behavior that can do more harm than good.  There may be an element of addiction involved that began with an innocent anxiolytic effect.