Magritte - Collective Invention, 1934



Introduction

When faced with an environmental perturbant, animals must either adapt or face extinction. Adaptation may be accomplished at the species and/or population level.

Physiological adaptation is accomplished at the individual level, by adjusting behavior, organ-system dynamics, molecular components and a host of other constituents so that survival may be maintained in the face of environmental stress.

Genetic adaptation can be accomplished at the species and/or population level. Interspecies adaptation reflects the evolutionary segregation of species into specific niches that are compatible with their molecular and physiological machinery. Intraspecies variability provides the genetic plasticity for species survival at the expense of some individuals by reshuffling the gene pool of populations.

The respiratory complex and specifically hemoglobins are perhaps the best system to study species, population and individual adaptation to environmental stress because respiration exists at the ‘organism-environment interface.’ Fish are particularly useful in such studies because they respond directly to such environmental variables as temperature, oxygen, pH, salinity and carbon dioxide which can be measured and controlled in a defined way, making them excellent model parameters to study the strategies of adaptation to environmental change.

Molecular Ecology of Teleost Fish Hemoglobins: Strategies for Adapting to Changing Environments – Dennis A. Powers, from the Symposium on Respiratory Pigments, Richmond, Virginia, Dec. 1978