All Physics Faculty Publications

Title

Evidence for Complex, Collective Dynamics and Emergent, Distributed Computation in Plants

Document Type

Article

Journal/Book Title/Conference

Proceedings of the National Academy of Sciences

Volume

101

Issue

4

Publication Date

1-27-2004

First Page

918

Last Page

922

Abstract

It has been suggested that some biological processes are equivalent to computation, but quantitative evidence for that view is weak. Plants must solve the problem of adjusting stomatal apertures to allow sufficient CO2 uptake for photosynthesis while preventing excessive water loss. Under some conditions, stomatal apertures become synchronized into patches that exhibit richly complicated dynamics, similar to behaviors found in cellular automata that perform computational tasks. Using sequences of chlorophyll fluorescence images from leaves of Xanthium strumarium L. (cocklebur), we quantified spatial and temporal correlations in stomatal dynamics. Our values are statistically indistinguishable from those of the same correlations found in the dynamics of automata that compute. These results are consistent with the proposition that a plant solves its optimal gas exchange problem through an emergent, distributed computation performed by its leaves.

Comments

Published by the National Academy of Sciences in Proceedings of the National Academy of Sciences USA. Publisher PDF is available through the link above. Publisher requires a subscription to access the article.

http://www.pnas.org/content/101/4/918.short