杏吧原创

鈥淟IFE made by humans rather than nature鈥� is how Christopher Langton describes the goal of the discipline whose development he has promoted vigorously for more than a decade. The systems that Langton and his followers create and observe live in computers and even in cyberspace. They have the properties of life, although high-school biology texts might not concede that appellation so readily. Artificial life 鈥� known to aficionados as A-life 鈥� is undoubtedly intellectually stimulating and, if it survives the test of reality, promises insights into nature鈥檚 own creations as well as advancing beyond them.

In his editor鈥檚 introduction to Artificial Life: An Overview, Langton draws an analogy with chemistry and the prerequisite of synthesising chemicals unknown in nature in order to understand the laws of nature. The same is true of biology, he says. 鈥淭he set of biological entities provided to us by nature, broad and diverse as it is, is dominated by accident and historical contingency.鈥� We expect that 鈥渓awful regularities鈥� will be at work here, but these regularities will be uncovered 鈥渙nly by exploring the much larger set of possible biological entities鈥�. Artificial Life gives a view of some of those possibilities, albeit still in their infancy.

The volume is assembled from the first three issues of the journal of the same name and is intended as a 鈥渉igh-level index to the artificial life enterprise鈥�. It is a weighty work, and will be immensely valuable to those committed to serious study of the state of the art and its future directions. The 17 chapters display the tremendous interdisciplinary range of the subject 鈥� from evolutionary biology to physics, from culture to ecosystems, from chemistry to technology 鈥� and readers familiar with the field will recognise the names of the major players in the list of contents.

The material is too dense to be summarised in a short review, but a few selected titles of chapters give a flavour of what is on offer: 鈥淎rtificial life as a tool for biological research鈥�; Visual models of morphogenesis鈥�; 鈥淐haos as a source of complexity and diversity in evolution鈥�; 鈥淐omputer viruses as artificial life鈥�; 鈥淏eyond digital naturalism鈥�; 鈥淟evels of functional equivalence in reverse engineering鈥�. And in a short contribution, the Tufts University philosopher Daniel Dennett urges his fellow scholars to consider A-life as 鈥渁 new way of doing philosophy鈥� and not simply as 鈥渁 new object worthy of philosophical attention using traditional methods鈥�.

The book also addresses social issues because, Langton notes, it is 鈥渋mportant to understand how a field fits into the web of science and society鈥�. If Frankenstein鈥檚 monsters of sorts are in the making here, the practitioners need to be aware of where they are heading and of their impact.