Genealogical Approach

Despite the focus here on theoretical chemistry, a genealogical approach differs from the history-of-ideas tradition in historiography in that ideas do not determine the course of scientific development but instead become one element in a spectrum of resources upon which scientists may draw. When ideas, instruments, and methods become a part of written literature, they also become a part of collective memory which could be reenacted at different historical moments. Central to this story of the Chemical Revolution are the methods or techniques—material, social, and literary—that contribute to the stabilization of a scientific tra-... 

Kroken, S., Taylor, J.W. (2001). A gene genealogical approach to recognize phylogenetic species boundaries in the lichenized fungus Letharia. Mycologia 93,38-53. 

The reader will recall that in Chapter 2 we gave examples of H2 calculations in which the orbitals were restricted to one or the other of the atomic centers and in Chapter 3 the examples used orbitals that range over more than one nuclear center. The genealogies of these two general sorts of wave functions can be traced back to the original Heitler-London approach and the Coulson-Fisher[15] approach, respectively. For the purposes of discussion in this chapter we will say the former approach uses local orbitals and the latter, nonlocal orbitals. One of the principal differences between these approaches revolves around the occurrence of the so-called ionic structures in the local orbital approach. We will describe the two methods in some detail and then return to the question of ionic stmctures in Chapter 8. 

Another approach to using permutational symmetry is to consider not the genealogical subgroup chain of Eq. 6.17, but adaptation to the alternative subgroup... 

These seven italicized criteria are integrated into a variety of (GDS) schemes thus allowing construction of hyperbranched macromolecular structures referred to as dendrons or dendrimers . A direct consequence of this strategy is a systematic molecular morphogenesis [1] with an opportunity to control "critical molecular design parameters (CMDP s) (i.e., size, shape, surface chemistry, topology and flexibility) as one advances with covalent connectivity from molecular reference points (seeds) of picoscopic/sub-nanoscopic size (i.e.. 0.01-1.0 nm) to precise macromolecular structures of nanoscopic dimensions (i.e., 1.0-100 nm) [2]. Genealogically directed synthesis offers a broad and versatile approach to the construction of precise, abiotic nanostructures with predictable sizes, shapes and surface chemistries. 

Using any of the above methods, the genealogical aspects of these synthetic approaches become obvious in that these synthetic operations involve/manifest all or a portion of the genealogical components listed below ... 

How does the genealogically directed synthesis (GDS) approach compare to these above strategies for the construction of nanoscopic structures The following features differentiate this method ... 

MS" genealogical mapping - approaches for structure elucidation of novel products of consecutive fragmentations of morphinans. Rapid Conunun. Mass Spectrom., 14 (2000) 250. 

In Hennig s approach true genealogical relation can only be concluded from the common (shared) presence of new developed characters. The primitive condition does not count, at least not as an argument to gro- i taxa together. 

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