  Emergent behavior that appears at a given level of organization may be
characterized as arising from an organizationally lower level in such a way
that it transcends a mere increase in the behavioral degree of complexity. It
is therefore to be distinguished from systems exhibiting chaotic behavior, for
example, which are deterministic but unpredictable because of an exponential
dependence on initial conditions. In emergent phenomena, higher-levels of
organization are not determined by lower-levels of organization; or, more
colloquially, emergent behavior is often said to be "greater than the sum of
the parts". The concept plays an especially important but contentious role in
the biological sciences. This essay is intended to demystify at least some
aspects of the mystery of emergence.
