January 23. Paleoecology

• HOMEOSTASIS
• balancing of conditions by coordination of complex physiological processes to approximate steady-state conditions in the face of fluctuating environment
• capacity of a system to maintain a constant state; regulate itself around an immobile set point
• HOMEORRHESIS
• capacity of a system to maintain a constant flow; system is regulated around an adjustable point
• FUNCTIONAL RANGE
• LEIBIG'S LAW OF THE MINIMUM: those environmental factors which are minimum supply are limiting to organisms
• Shelford (1913): added upper limits and considered interactions among factors (synergistic effects)
• Odum and Odum (1913): considered both quantity and variability of environmental factors
• Hutchinson (1957; 1967): introduced conceptual model of environment as multidimensional space (hypervolume)
• total (prospective) function range: in a hypervolume for which each dimension is an environmental parameter, the function range is a subvolume within which an organism can exist
• controlled by the genotype of an organism; smaller hypervolume that is 'inhabited' by phenotype that actually develops
• prospective environment: total range of all possible combinations of environmental parameters
• realized environment (biospace): combination that actually exists at a given place and time
• realized functional range: overlap between the prospective functional range and the realized environment
• realized functional range changes as biospace changes; organism must adjust to these changes by homeorrhesis
• failure = death

SYSTEMS ANALYSIS

• be familiar with terms and concepts in "The Utter Basics" and "The Twist That Is Life" handout
• in particular: cybernetic vs. autopoietic system