Browsing by Subject "Individuation"

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    Evolutionary Trends in the Individuation and Polymorphism of Colonial Marine Invertebrates
    (2007-05-10T16:02:15Z) Venit, Edward Peter
    All life is organized hierarchically. Lower levels, such as cells and zooids, are nested within higher levels, such as multicellular organisms and colonial animals. The process by which a higher-level unit forms from the coalescence of lower-level units is known as “individuation”. Individuation is defined by the strength of functional interdependencies among constituent lower-level units. Interdependency results from division of labor, which is evidenced in colonial metazoans as zooid polymorphism. As lower-level units specialize for certain tasks, they become increasing dependant on the rest of the collective to perform other tasks. In this way, the evolution of division of labor drives the process of individuation. This study explores several ways in which polymorphism evolves in colonial marine invertebrates such as cnidarians, bryozoans, and urochordates. A previous study on the effect of environmental stability on polymorphism is revisted and reinterpreted. A method for quantifying colonial-level individuation by measuring the spatial arrangement of polymorphic zooids is proposed and demonstrated. Most significantly, a comparison across all colonial marine invertebrate taxa reveals that polymorphism only appears in those colonial taxa with moderately to strongly compartmentalized zooids. Weakly compartmentalized and fully compartmentalized taxa are universally monomorphic. This pattern is seen across all colonial marine invertebrate taxa and is interpreted as a “rule” governing the evolution of higher-level individuation in the major taxa of colonial marine invertebrates. The existence of one rule suggests that there may be others, including rules that transcend levels of biological hierarchy. The identification of such rules would strongly suggest that new levels in the hierarchy of life evolve by a universal pattern that is independent of the type of organism involved.
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    Response decision processes and externalizing behavior problems in adolescents.
    (Dev Psychopathol, 2002) Fontaine, Reid Griffith; Burks, Virginia Salzer; Dodge, Kenneth A
    Externalizing behavior problems of 124 adolescents were assessed across Grades 7-11. In Grade 9, participants were also assessed across social-cognitive domains after imagining themselves as the object of provocations portrayed in six videotaped vignettes. Participants responded to vignette-based questions representing multiple processes of the response decision step of social information processing. Phase 1 of our investigation supported a two-factor model of the response evaluation process of response decision (response valuation and outcome expectancy). Phase 2 showed significant relations between the set of these response decision processes, as well as response selection, measured in Grade 9 and (a) externalizing behavior in Grade 9 and (b) externalizing behavior in Grades 10-11, even after controlling externalizing behavior in Grades 7-8. These findings suggest that on-line behavioral judgments about aggression play a crucial role in the maintenance and growth of aggressive response tendencies in adolescence.