Among the unresolved topics in evolutionary biology and behavioral ecology are the origins, mechanisms, evolution, and consequences of developmental and phenotypic diversity. In an attempt to address these challenges, plasticity has been investigated empirically and theoretically at all levels of biological organization—from biochemical to whole organism and beyond to the population, community, and ecosystem levels. Less commonly explored are constraints (e.g., ecological), costs (e.g., increased response error), perturbations (e.g., alterations in selection intensity), and stressors (e.g., resource limitation) influencing not only selective values of heritable phenotypic components but, also, decisions and choices (not necessarily conscious ones) available to individuals in populations. Treating extant mammals, the primary purpose of the proposed work is to provide new perspectives on common themes in the literature on robustness (“functional diversity”; differential resistance to “deconstraint” of conserved elements) and weak robustness (the potential to restrict plasticity and evolvability), plasticity (variation expressed throughout the lifetimes of individuals in a population setting “evolvability potential”), and evolvability (non-lethal phenotypic novelties induced by endogenous and/or exogenous stimuli). The proposed project will place particular emphasis upon the adaptive complex in relation to endogenous (e.g., genomes, neurophysiology) and exogenous (abiotic and biotic, including social environments) organismal features discussed as regulatory and environmental perturbations with the potential to induce, and, often, constrain variability and novelty of form and function
Table of Contents
1.0 Introduction: What paths to mean reproductive success of individuals and shifting mean fitness of mammalian populations?
1.1 Spatiotemporal variations in microhabitat from molecular to phenotypic levels of organization
2.0 Mammals: From humble vertebrate beginnings to global terrestrial dominance
2.1 Robustness matters: Appearance and early evolution of mammals
2.2 Order Monotremata: Good work ethic, predictable and abundant food, lots of luck
2.3 Subclass Theria (Infraclasses Metatheria and Eutheria): “Tinkering” with contents of a generalized “toolkit”
2.4 The mammalian placenta: The “intimate connection” between female reproductive physiology, offspring heat regulation, and life history strategies
3.0 Variability of mammalian thermal niches: Differential effects of local and global environmental heterogeneity
3.1 Are there general laws of mammalian thermal niches and of thermal tolerance evolvability?
3.2 Is genetic heterogeneity an advantage in fine-grained conditions?
3.3 Spatiotemporal variability in microclimates and macroclimates: Seasonal forests as natural laboratories for theoretical, descriptive, and experimental research on mammalian thermal tolerances
3.4 Thermal tolerances of mantled howler monkeys are preadapted to stressful regimes
4.0 Robustness and polyphenisms in mammals: “Core processes”, repatterning, “constrained variation”, and “regulatory logic”
4.1 Laboratory studies of mammals can contribute to an understanding of robustness and plasticity: Flück’s research program as a model
4.2 Mammalian motor patterns targeting the neck: The “regulatory logic” of molecules and cells
4.3 Stereotyped motor patterns as polymorphisms: An ESS approach to interactions between females of different dominance rank
4.4 Adaptive polyphenism: “Spatiotemporal compartmentalization” of discontinuous phenotypic variation (Nijhout 2003)
4.5 Benefits of group membership: “Information centres”, flexible access to limiting resources, and phenotype-buffering
5.0 Learning may generate phenotypic variability in heterogeneous regimes
6.0 Discussion: Stimulus ↔ Response ↔ Stimulus
7.1 Coda References