Dorion Sagan

Community living long before man: fossil and living microbial mats and early life

Microbial mats are layered communities of bacteria that form cohesive structures, some of which are preserved in sedimentary rocks as stromatolites. Certain rocks, approximately three and a half thousand million years old and representing the oldest known fossils, are interpreted to derive from microbial mats and to contain fossils of microorganisms. Modern microbial mats (such as the one described here from Matanzas, Cuba) and their fossil counterparts are of great interest in the interpretation of early life on Earth. Since examination of microbial mats and stromatolites increases our understanding of long-term stability and change, within the global environment, such structures should be protected wherever possible as natural science preserves. Furthermore, since they have existed virtually from the time of lifes origin, microbial mats have developed exemplary mechanisms of local community persistence and may even play roles in the larger global environment that we do not understand.

Epilogue: The Uncut Self

Foucault [1] full circle, not based on the rectilinear frame of reference of a painting, mirror, house, or book, and with neither “inside” nor “outside” but according to the single surface of a Moebius strip. This is not the classical Cartesian model of self, with a vital ensouled res cogitans surrounded by that predictable world of Newtonian mechanisms of the res extensa; it is closer to Maturana and Varela’s conception of autopoiesis, a completely self-making, self-referring, tautologically delimited entity at the various levels of cell, organism, and cognition [2]. It would be premature to accuse us therefore of a debilitating biomysticism, of pandering to deconstructive fashion, or, indeed, of fomenting an academic “lunacy” or “criminality” that merits ostracism from scientific society, smoothly sealed by peer review and by the standards of what Fleck calls a “thought collective” [3]. Nor would it be timely to label and dismiss us as antirational or solipsist.