Biology Reference
In-Depth Information
from any property that is present in the molecules in isolation or even be com-
pletely new. Noting that many of these properties are crucial aspects of life, they
call these properties emergent. Then, on the basis of the fact that in the absence
of vital forces, living systems also consist of nothing but a dynamic constella-
tion of molecules that interact, they consider that, with the exception of cases
of deterministic chaos, these emergent properties should be explainable mech-
anistically. They go even further by claiming that the construction of accurate
computer replica enables the calculation of emergent properties. Thus emergence
is perceived not only as being explainable, but also as being calculable on the
basis of quantitative detailed kinetic models. The models are constructed on the
basis of kinetic and binding constants measured for components in isolation but
under the precise conditions that reign
in vivo
. The crux is whether the behavior
in vivo
will show up in the reconstruction of the system
in silico
. If so, the mech-
anistic model is also a reductive model, because only properties from the lower
(component) level of organization suffice to reconstruct the system's behavior.
The mechanistic model is not just a reductionist model, however, as the latter
would maintain that the system properties are already present in the individual
components, whereas Westerhoff and Kell argue that emergent system behavior
arises in the nonlinear interactions between the molecules, as will be calculated
in the silicon cell replicas. Even though the capability to interact is already
present in the individual molecules, the interaction is not and the new properties
do not arise in the abilities to interact but from the actual interactions. The
system's emergent properties show up only when the interactions are actually
happening. System's behavior is not taken for granted beforehand. Emergence
is calculable and, in this view, eventually life would be calculable.
In the chapter of Richardson and Stephan, the concept of emergence is based
exactly on such a failure of system behavior to be calculated from the component
properties: system behavior should be called (strongly) emergent only if system
behavior cannot be inferred or predicted from the behavior of components in
isolation (or smaller subsystems). If one knows the behavior of components
within the systemic context, then it is possible to give a mechanistic explanation
of any system's behavior. This definition is stronger than Westerhoff and Kell's
but follows the same type of reasoning.
In contrast, but consistent with the historical definition mentioned above,
metaphysicians claim that properties (e.g.,
qualia
) are emergent if they cannot be
predicted even from the complete knowledge of components' behavior within the
system. In order to approach reality better, knowledge should be gathered about
component behavior in subsystems in isolation, encompassing a larger portion of
cellular metabolism, or it may be required to study component behavior within
the entire system. In the latter case, besides lower level component knowledge,
system knowledge is required for the reconstruction of system behavior. We
argue that this notion of emergence is not useful for natural sciences in general
