Uncertainty, Emergence, and Statistics in Dendrochronology - Dendroclimatology - page 85

For object-based models to work in the way described by Hatcher and Tofts
( 2004 ) , 'every object in the system' must be known. This we maintain is the funda-
mental flaw of constitutive reductionism if one were to apply it to tree-ring research.
We do not have a complete understanding of the evolution of a given tree species
that has resulted in its genotypic definition as a species, its phenotypic expression
as an organism, and its expressible range of phylogenetic responses to its opera-
tional environment. Consequently, many properties of tree-ring series can only be
discovered by experiment. So in our view, the proposed method of Hatcher and
Tof t s ( 2004 ) does not solve the emergence-versus-reductionism problem in tree-ring
analysis in favor of constitutive reductionism, because there will never be enough
known 'objects in the system' to model tree growth at the genus and species levels
needed for dendrochronology. Nor is it likely that their approach will even work
in the physical world, where theory has historically been based on mathematically
rigorous forms of explanatory reductionism.
Nobel Prize-winning physicist Robert Laughlin and coauthor David Pines
(Laughlin and Pines 2000 ) argue convincingly in their paper The Theory of
Everything that reductionist methods 'have succeeded in reducing all of ordinary
physical behavior to a simple, correct Theory of Everything only to discover that
it has revealed exactly nothing about many things of great importance' (emphasis
added), and they give several examples in physics where this is undoubtedly the
case. Laughlin and Pines ( 2000 ) go on to state that 'emergent physical phenomena
regulated by higher organizing principles have a property, namely their insensitivity
to microscopics , that is directly relevant to the broad question of what is knowable
in the deepest sense of the term' (emphasis added). This means that even if we know
the exact laws of physics at microscopic scales, we cannot use them to deduce the
macroscopic properties of something as common as a crystalline solid, because the
macroscopic world is 'regulated by higher organizing principles' that are distinct
from those at the microscopic level. This harkens back to Ernst Mayr's earlier ref-
erence to Neils Bohr's comment about water. Consequently, 'living with emergence
means, among other things, focusing on what experiment tells us about candidate
scenarios for the way a given system might behave before attempting to explore the
consequences of any specific model' (Laughlin and Pines 2000 ; emphasis added).
Even earlier, Nobel Prize-winning physicist Philip Anderson ( 1972 ) made similar
arguments in his paper More is Different , which stimulated much of the thinking
that went into the paper by Laughlin and Pines ( 2000 ) . Those interested in this very
important topic are strongly encouraged to read the papers by Anderson ( 1972 ) ,
Laughlin and Pines ( 2000 ) , and the recently published book A Different Universe:
Remaking Physics from the Bottom Down (Laughlin 2005 ) .
Emergence is an inherent macroscopic property of complex systems in both the
physical and biological worlds that cannot be ignored or rejected by reductionist
arguments. Its presence in dendrochronological studies should therefore be expected
and, indeed, welcomed because it means that we can expect surprises in our tree-
ring studies that make the science of dendrochronology fun and thought provoking.
Thus, we should approach our analyses with a good deal of exploration in mind and
follow statistician John Tukey's exhortation that we be data detectives (Tukey 1977 ) .