EVOECOTOXICOLOGY: THE SCIENCE CONCERNED WITH THE RECORD IN LIVING ORGANISMS OF THE INTERACTIONS WITH CHEMICAL AND PHYSICAL AGENTS DURING THE EVOLUTIONARY PROCESS.

JORGE HERKOVITS

Frontier Perspectives

Temple University

Lugar: Filadelfia; Año: 2006 vol. 15 p. 14 - 22

1062-4767

Although it is generally accepted that environmental stress features can select resistant individuals within species and resistant species within ecosystems, for most of the evolutionary process our understanding of both the environment and life forms is extremely limited and controversial. This article focuses on the hypothesis that living organisms at ontogenetic stages could be considered as biomarkers of the successive interactions with the environmental agents during the evolutionary process. In this context   the (almost) anaerobic metabolism at blastula stage embryo could reflect the existence of multicellular organisms in the deep anoxic Earth while the transition to aerobic metabolism at gastrula could be related to the evolution towards tridermic organisms around 2 billion years ago. Complementarily the high resistance to physico chemical agents at early developmental stages could reflect that living organisms had to cope with very adverse environmental conditions during at least 2 billion years while the high susceptibility at developmental stages with complex cell differentiation and morphogenetic processes (e.g. organogenesis and metamorphosis) contribute to the vision that those cell activities were achieved in times of low environmental stress conditions. Taking into account that mass extinction events could be associated to chemical bomb scenarios, the resistance at developmental stages to physico chemical agents could contribute to the understanding of the maximal environmental stress supported by any organism during its phylogenesis.  Evoecotoxicology by considering living organisms as biomarkers of the interactions with chemical and physical agents during the evolutionary process could contribute to a better understanding of the evolutionary process in the Earth.