Signals and Boundaries: Building Blocks for Complex Adaptive Systems (Hardcover)

Complex adaptive systems (cas), including ecosystems, governments, biological cells, and markets, are characterized by intricate hierarchical arrangements of boundaries and signals. In ecosystems, for example, niches act as semi-permeable boundaries, and smells and visual patterns serve as signals; governments have departmental hierarchies with memoranda acting as signals; and so it is with other cas. Despite a wealth of data and descriptions concerning different cas, there remain many unanswered questions about "steering" these systems. In Signals and Boundaries, John Holland argues that understanding the origin of the intricate signal/border hierarchies of these systems is the key to answering such questions. He develops an overarching framework for comparing and steering cas through the mechanisms that generate their signal/boundary hierarchies.

Holland lays out a path for developing the framework that emphasizes agents, niches, theory, and mathematical models. He discusses, among other topics, theory construction; signal-processing agents; networks as representations of signal/boundary interaction; adaptation; recombination and reproduction; the use of tagged urn models (adapted from elementary probability theory) to represent boundary hierarchies; finitely generated systems as a way to tie the models examined into a single framework; the framework itself, illustrated by a simple finitely generated version of the development of a multi-celled organism; and Markov processes.

複雜適應系統（CAS），包括生態系統、政府、生物細胞和市場，以複雜的層次性邊界和信號組成。例如，在生態系統中，生態位充當半透性邊界，氣味和視覺模式則作為信號；政府擁有部門層次結構，備忘錄則作為信號；其他CAS也是如此。儘管有大量關於不同CAS的數據和描述，但關於“引導”這些系統仍然存在許多未解答的問題。在《信號和邊界》中，約翰·荷蘭（John Holland）認為理解這些系統複雜信號/邊界層次結構的起源是回答這些問題的關鍵。他建立了一個總體框架，通過生成其信號/邊界層次結構的機制來比較和引導CAS。

荷蘭提出了一條發展該框架的路徑，強調代理人、生態位、理論和數學模型。他討論了理論建構、信號處理代理人、網絡作為信號/邊界交互作用的表示、適應、重組和繁殖、使用標記的瓮模型（改編自基礎概率理論）來表示邊界層次結構、有限生成系統作為將所研究的模型納入單一框架的方法、框架本身，以一個簡單的有限生成版本的多細胞生物發展過程作為例子，以及馬爾可夫過程。