Biology Reference
In-Depth Information
Identifying parts and operations is a challenging activity. Not every way of
carving up a mechanism yields working parts - parts which perform operations
that figure in the explanation of the ability of a mechanism to perform its function.
Moreover, it is often challenging to figure out what sorts of operations might give
rise to the function. Biochemistry only made headway when biochemical groups
were identified and biochemical reactions were recognized as operations over
such groups (Holmes, 1992). There are many cases in which researchers sought
evidence for one sort of operation only to discover later that a very different
type of operation was responsible for the phenomenon. A classic example is
that biochemists, following the lead of E. C. Slater (1953), assumed that the
energetic intermediate in ATP synthesis in oxidative phosphorylation would
involve a chemical compound and only gradually recognized, after Mitchell
(1961) advanced a very different alternative relying on an ion gradient over a
membrane, that they were seeking the wrong kind of operation (Allchin, 1997).
A common frustration in biological research is the inability to reproduce the
phenomenon once one has assembled what appear to be all the component parts
and operations. In many cases the failing is that there remains yet unknown
parts or operations. But in other cases the failing involves the third feature in my
characterization of mechanisms, organization. Lip service is often given to the
fact that components of a mechanism must be organized, but the importance of
organization is often underappreciated. Yet, it is organization that causes parts
of the mechanism to behave in ways they do not in isolation and enables the
mechanism as a whole to accomplish things that none of the components alone
can do. What is possible when components are put together in creative ways
is often obscured when one focuses just on the components themselves. What
is learned about the part in conditions in which a researcher has removed it
from the context of the mechanism may not include how it will operate in the
organized structure. One can appreciate this point better by turning one's focus
from science to engineering. Engineers do not build new devices by creating
matter with distinctive properties
ab initio
. Rather, they start with things that
already exist and put them together in novel ways. What can be accomplished
when the parts are put together is typically far from obvious. Creativity is
required, and accordingly engineers can win patents and fame for developing
a new design that enables old parts to perform new operations. The only thing
the engineer added to what already existed was organization, but this is what
is critical in developing mechanisms that perform tasks that initially seemed
impossible to perform with existing components.
3. THE VITALIST CHALLENGE
Although the search for mechanisms within biology has not been particularly
controversial since the beginning of the twentieth century, it was heatedly
