Agriculture Reference
In-Depth Information
whAt Is nutRItIon?
Entropy
is a universal physical quantity that defines the second law of thermody-
namics: Energy dissipates, maximizing the disorder in the universe. However, liv-
ing organisms defy the decay into equilibrium with the environment by feeding on
negative entropy and decreasing their disorder. By living, the organism maintains
itself in a stationary or low level of entropy (Schrödinger, 1956, p. 73). Nutrition is
the process by which the organism is continually consuming negative entropy from
the environment. In humans, the ingested negative entropy consists of foods. Here,
we examine the genomic history of the processes of digesting the negative entropy
contained in food macronutrients: proteins, fats, and carbohydrates. In plants, the
most powerful supply of negative entropy is from sunlight. All living organisms
concentrate a “stream of order” from the environment to escape the atomic chaos of
entropy and display the power of maintaining self and expressing orderly events (p.
75). These interwoven events are guided by genetic mechanisms that are completely
at odds with the “probabilistic mechanisms” of physics to ensure the living paradigm
of orderliness. Growth and reproduction are due to an “order-from-order” principle
(p. 78). The genome thus defies the disorder of the physical universe. A fundamental
difference between the physical and biological universes is the harmony that bridges
the genome of single with multicellular organisms. By defying the laws of physics,
living cells were described as “the finest masterpiece ever achieved along the lines
of the Lord's quantum mechanics” (p. 83).
whAt Is the hIstoRy of lIfe?
Planet earth is thought to have formed about 4.5 billion years ago (bya). The com-
mon ancestor of contemporary life forms populated the earth about 3.5 bya (Pollard
et al., 2008, p. 17). Biochemical features stored in all present life forms suggest
that this primitive microscopic cell had about 600 genes encoding DNA, protein
synthetic machinery, and a plasma membrane and with mechanisms for digest-
ing polymeric molecules and assimilating negative entropy from the environment.
Over about 1.7 bya, distinctive living species evolved. On the basis of evolutionary
records, preserved in their genomes, living organisms are divided into three primary
domains: archaea, bacteria, and eukarya. Genomic diversification evolved by muta-
tion, duplication, and divergence, and lateral transfer of DNA (p. 19). Photosynthesis
originated about 3 bya by symbiosis by two different families of bacteria. About 2.5
bya, a lateral transfer event brought the two genomes for photosynthesis together in
cyanobacteria (blue-green algae). Sunlight energized the photosynthetic structures
to activate a proton gradient used to synthesize adenosine triphosphate (ATP) and the
many carbon compounds that living organisms required for negative entropy. About
2.4 bya, cyanobacteria produced most of the oxygen in the Earth's atmosphere as
the product of photosynthesis. This increase in oxygen revolutionized the chemical
environment for all other species of organisms.
Genomic history indicates that the present eukaryotic lineages diverged between
2 and 1 bya (Hedges et al., 2004; Figure 2.1). Cell surface membranes characterize
both eukaryotes and prokaryotes; however, internal compartmentalization is lacking
