Thinking About Biology: An Invitation To Current Theoretical Biology

by Wilfred D. Stein, Francisco J. Varela (Editor)

No science has ever been done without an indissoluble link between theory and fact: facts are colored by the theoretical spectacles on puts on, just as much as theory is shaped by the results of empirical observation. Theoretical biology is a broad and rapidly growing field where this link is actually explored with passion and discipline. The chapters of this book have been chosen to give the student of theoretical biology the flavor of current exciting research in the field. The eleven chapters are divided into three broad sections: the emergence of life, the development of the individual, and the study of the interaction between individuals and species.

Genres: Biology

352 pages, Hardcover

First published January 1, 1993

Reviews

[William Bies · Rating 3 out of 5]

Those who share John Horgan’s fears about a looming so-called ‘end of science’ must be ignoring theoretical biology, a discipline still very much in its infancy! Perhaps elementary particle physics has been thoroughly mined by now, but as far as a theory of living organisms goes, we find ourselves at an early stage when it remains unsettled even what the basic concepts pertinent to an understanding of life ought to be. Yet, for all the ample scope for unrestrained speculation this circumstance permits, what is special about theoretical biology are two things: first, in related disciplines such as chaos and complexity theory, physicists have in recent decades arrived at a wealth of sophisticated ideas that can be checked in model systems (both theoretically and experimentally) and that, therefore, offer a prime opportunity for an exploration of the behavior of living organisms, where, it stands to reason, they ought to find some applicability; and second, with the continued flourishing of molecular and developmental biology as empirical disciplines, we are confronted with a profusion of experimental data awaiting an apt analysis in theoretical terms. Not only this, in biology it would be comparatively easy to carry out an experimental test of a promising hypothesis – no need to spend twenty years and multiple billions of dollars to build another particle accelerator!

With considerations such as these in mind, how ought one to delve into the burgeoning literature? For in a field so young one cannot count on there being any established reference works, as is the case in more mature departments of knowledge. Rather, one enjoys the excitement of following work in progress. Thus, the curious student must be pleased that editors Wilfred Stein and Francisco J. Varela have prepared another volume of lecture notes in the series published by the Santa Fe Institute for Studies in the Sciences of Complexity, entitled Thinking about Biology: An Invitation to Current Theoretical Biology (Addison-Wesley, 1993). Though thirty years old, one cannot say that these lectures notes have become dated, for things tend to move slowly in a domain of fundamental theorizing. Perhaps a handful of erstwhile hot topics have been superseded and displaced by newer vogues, which of course will go missing here, but what one does have in the present volume affords good food for thought.

In their introductory essay, the editors expressly aim to offer a sample of current thinking in biology in order to promote a fruitful style of thinking for newcomers. Biology is characterized by multiple levels: macro-, meso- and micro-. Macrotheory is represented in this volume by speculations on the origin of life and self-organized criticality; mesotheory by the morphogenetic gradient and immune network; and microtheory by the example of Hodgkin and Huxley’s model of the transmission of neural signals and by numerous instances in the present work. Stein and Varela declare a wish to avoid anti-heroes, by which they mean old professors who have specialized in a narrow domain and, at the close of their career, want to engage in speculation, fruitlessly because for them there is no intrinsic interconnection with current work or likelihood of starting a new research program in order to try them out.

Section I is devoted to the emergence of life, Section II to development and the individual and Section III to the interaction between individuals and species, as evidenced in phenomena such as self-organization, gastrulation, coherence and antigenic identity (how to recognize self as opposed to intruder). What caught this reviewer’s attention at the time (ages ago) of his first reading was especially the article by Pier Luigi Luisi, ‘Defining the Transition of Life: Self-Replicating Bounded Structures and Chemical Autopoiesis’[pp. 17-39]. Luisi is interested in what would constitute minimal life, as defined by an autopoietic unit – necessarily a holistic conception, for in his view, the origin of life is not to be ascribed to any given subunit but to the interplay among them as a whole. An autopoetic unit must display operational closure, which Luisi proposes to characterize as self-bounded, self-generating and self-perpetuating. In later sections of this chapter, Luisi discusses possible chemical incarnations of a minimal autopoietic unit and, in particular, micelles as self-replicating systems which he presents as a potential path to the origin of life. Then, also, a section on going from micelles to vesicles, i.e., micelles equipped with biological functionality. The final topic Luisi treats is template-based self-replication.

Other interesting chapters include Jay E. Mittenthal, Bertrand Clarke and Mark Levinthal, ‘Designing bacteria’ [pp. 65-103], from a network-centric point of view; Lewis Wolpert, ‘Gastrulation and the evolution of development’ [pp. 169-182]; and lastly, Stuart Kauffman, ‘Requirements for evolvability in complex systems: Orderly dynamics and frozen components’ [pp. 269-301]. Here, Kauffman outlines his idea of Boolean dynamical networks as a description a genetic regulatory system. While clearly just a toy model, Kauffman nevertheless manages to uncover several unsuspected coordinated phenomena that could well translate to real organisms.

Let the budding theoretical biologist feast upon these wide-ranging lectures and, perhaps, garner a promising idea or two!