Turtles… dialectics all the way down

“Biology has traditionally defined individuals by the criteria of anatomy (organisms separated from the environment), physiology (organisms whose parts work toward a common end), development (organisms derived from a common precursor cell), genetics (autopoietic organisms whose cells contain the same genome), immunology (organisms that reject non-self), and evolution (that which is selected). Recent studies show that symbiosis, rather than being an exception to the rule, is the rule. A new mode of individuality, the holobiont, has been proposed, consisting of the larger organism and its persistent colonies of symbionts. The holobiont is a multi-lineage organism whose cells function through co-metabolic pathways, whose development integrates the life cycles of several species, and whose phenotype often depends on alleles found in both “host” and symbionts. Natural selection, then, may select for consortia, or teams, of species, and the tree of life may be more like real (i.e., holobiont) trees than we had thought. Birth is more than the generation of a new individual. It also concerns the continuity of the communities. The ramifications of this new view of co-dependent life where “becoming with the other” may be as important as “survival of the fittest” will be examined.”