Biology Reference
In-Depth Information
Living Systems
(Informed Matter)
Transformation of Matter
Transport of Matter
¾ Exponent
2/3 Exponent
Kleiber' rule
Rubner' rule
Fig. 15.14 The living systems as
informed matter
defined as the complementary union of matter/
energy and information/life (see Table 2.5 in Sect.
2.3.1
) that is supported by two dichotomous
processes -
mass transformation
and
mass transport
, ultimately driven by chemical reactions
catalyzed by enzymes acting as coincidence detectors (see Sect.
7.2.2
)
enzymes are coincidence detectors serving as the nodes of temporal branching
networks (Fig.
7.7
), it can be suggested that transformation of matter in cells scale
as the body mass raised to the power of 3/4, as proposed above. It is also possible that
certain dynamic traits are rate-limited by
transport
of matter and that of certain
others by
transformation
of matter, depending on the evolutionary, ontogenic, and
physiological conditions of the organisms under consideration, thereby exhibiting
either the 2/3 or 3/4 allometric exponents or some values in between as seems to be
the case (see Tables 1 and 2 in White and Seymour 2005). These ideas are
summarized in Fig.
15.14
.
As evident in Fig.
15.15
, the level of non-protein-coding DNA (i.e., dr-genes
found to increase rapidly with increasing biological complexity, for example, from
unicellular to multicellular organisms. The ratio of noncoding DNA to the total
DNA does not change much from
Nanoarchaeum equitans
through
Rickettsia
conorii
(spanning 67 unicellular species) but begins to rise sharply with
Rickettsia
prowazekii,
continuing to rise through 19 species (multicellular species), reaching
the maximum ratio with
Homo sapiens
(Mattick 2004). One plausible interpretation
of the data in Fig.
15.15
is that the noncoding portions of DNA encode the
information needed to organize in space and time the cells in multicellular
organisms in order to maintain their functions. This idea can be expressed using
the language of network sciences (Sect.
2.4
) (Barabasi 2002, 2009):
The coding regions of the DNA of amulticellular organismdetermine the intrinsic properties
of the nodes of a bionetwork and the noncoding DNA regions determine both the interactions
among the nodes and the space- and time-dependent control of their interactions in order
to accomplish evolutionarily selected functions of the organism.
(15.16)
