American Scientist

The Shattered Self: The End of Natural Evolution. Pierre Baldi. xiv + 245 pp. The MIT Press, 2001. $24.95.

In the 20th century, science and technology helped shape modernism and its radical new conception of what it means to be human. Rooted in a Freudian vitalism, this conception suggested that the true self was irrational, consumptive and perhaps ultimately unknowable. As radical as the modern human image was, however, it retained a traditional element—the notion that each person is unique, with precisely delimited boundaries demarcating self, other and world. The striking thesis of Pierre Baldi's new book, The Shattered Self, is that biological and computational sciences—whose major advances came only after modernism was firmly entrenched—are poised to shatter this facet of the self. In so doing, they will force us to rethink what it means to be human, from our beliefs about self, life and death to our understanding of intelligence and sexuality.

Baldi, the director of the Institute for Genomics and Bioinformatics at the University of California, Irvine, is well positioned to write a book probing the implications of biotechnologies and computer science. Intended for the layperson, the book is written in a nontechnical, accessible style, with more-technical material relegated to five appendices. In the opening chapter, Baldi does an admirable job of orienting the reader by outlining the decentering capacity of science, whereby a scientific understanding of reality replaces an intuitive one. Following this, Baldi provides an extremely lucid overview of molecular biology, providing the reader with the essentials for the probing discussions to come.

In chapters 4 through 7, Baldi explores biotechnology's decentering through such timely topics as emerging reproductive technologies, human cloning, stem cells and DNA morphing, along with even more exotic possibilities such as combining cloning with technologies used to artificially produce Siamese twins (as has been done with frogs) to create Siamese-twin clones of oneself. Some of the implications Baldi highlights seem a little questionable—for example, the possibility that reproductive technologies will make sexual behavior extinct. Human sexual behavior is only loosely tied to reproduction, as evidenced by female extended sexual receptivity, making it highly unlikely that sexual behavior will be marginalized as its reproductive role diminishes. On the whole, however, Baldi admirably avoids making predictions and instead focuses on charting the landscape of possibilities that might confront us.

As interesting as the central chapters are, the last third of the book is the most tantalizing. There Baldi departs from more-standard topical issues to explore the relationship between biotechnology and computation, two major forces that will shape the future. In the discussion of computation in chapter 8, information emerges as a central unifying theme. DNA is ultimately a medium of information; nature, biotechnologies and computers thus share the common currency of information. Because information can be distinguished from its physical substrates, the decentering power of new technologies lies in building interfaces between different kinds of information, ultimately translating the information that defines individuals into new media.

Baldi adds a number of intriguing back-of-the-envelope calculations to this discussion, including an estimate of how much information is contained in a lifetime of experience, or brain inputs: By his estimation, the amount is 2.2 X 10¹⁸ bits (about 2.7 X 10¹⁷ bytes), which at current rates of memory storage advances will be within the memory capacity of a typical personal computer in 27 years. Based on this, Baldi then investigates the information size of what he calls the external self, a complete genomic sequence together with the recording of all inputs and outputs of an individual's brain over a lifetime, which he estimates to be still on the order of 10¹⁸ bits, within reach of modern computer technology. The internal self, the amount of information required to capture the relevant structure of your brain that defines your identity, is larger—at least 10²⁷ bits—but might still be within reach of emerging technologies. Ultimately, your individuality is representable as a large but finite amount of information that could be stored and manipulated in new technologies.

These heuristic calculations illustrate that we inhabit an information space whose depth and complexity science is only beginning to fathom. According to Baldi, our growing capacity to manipulate this space may lead to the discovery that our self-conception is based on the wrong data. The intriguing idea here is that our self-conception, rooted in the notion of an enduring, discrete self, might be a useful but ultimately erroneous evolutionary adaptation that came about by inhabiting only the very tip of this information space. Baldi suggests that decentering will come through realizing that the key elements of this space—genomes, computations and minds—are fluid, continuous entities. Thus the boundary between self, other and world will increasingly blur and might eventually disappear as information flows freely among them.

Reflecting on these possibilities, Baldi suggests that our emerging capacity to manipulate this information space may well mean the end of natural evolution, as technologies allow us to reinvent ourselves. What we will become remains intriguing and ominous, making this probing book a valuable contribution to thinking about our future.—Steven R. Quartz, Division of Humanities and Social Sciences, and Computation and Neural Systems Program, California Institute of Technology