2
1 The Subject Matter and Methods of Comparative Biochemistry
The application of chemical concepts and
methods for investigations of the life processes
led to "physiological chemistry" or "chemical
physiology", which soon became an independent
discipline. The term "biochemistry" was first
introduced by Neuberg in 1903. Also, in biochemistry the comparison of different species
served at first to establish the consistency of basic
principles; . examples include Otto von Fuerth
(1903) in Comparative Chemical Physiology of
Lower Animals [9], and E. Baldwin (1937) in
Introduction to Comparative Biochemistry [1].
Noch (1958) quote Dixon and Webb in their
monograph on enzymes [6]:
"It is a remarkable fact that in general the catalytic properties, specificity, activity, affinities,
etc., of a given enzyme vary little with the source.
Although there may be slight physical differences
in a given enzyme when it is produced by different cells they are usually unimportant, and the
enzyme remains essentially the same enzyme."
In 1895 Emil Fischer had already pointed out
differences between enzymes of different origins.
At first, however, this, together with the species
and tissue specificity of other biochemical characters, was considered to be a methodical impediment to biochemical studies rather than a unique
scientific problem. Credit for emphasizing the
importance of phylogenetic considerations in biochemistry must go to Marcel Florkin with his
book L'evolution biochimique (1944). In his later
works this commendable scientist was also concerned with establishing "comparative biochemistry", as an illustration of the biochemical
diversity of organisms, alongside "general biochemistry", as lessons from the basic principles of
biochemical organization; examples are his book
Unity and Diversity in Biochemistry (1960) and as
editor of the handbooks Comparative Biochemistry (7 volumes 1960-1964, with H. S. Mason)
and Chemical Zoology (11 volumes 1967-1979,
with B. T. Scheer).
In the last two decades, the comparative and
phylogenetic approach to biochemistry has
become rather fashionable. Monographs dealing
with particular animal groups almost invariably
contain sections on comparative biochemistry,
and new monographs and reviews on comparative
biochemical subjects are constantly appearing.
The 13 volumes of Comprehensive Insect Physiology, Biochemistry and Pharmacology, published
simultaneously in 1985, a remarkable achievement by Kerkut and Gilbert, contain many chapters on biochemical themes [20]. Papers with
comparative or phylogenetic aims are not only to
be found in specialist journals, e.g. Comparative
Biochemistry and Physiology: Part B (Biochemistry) (December 1992 to Vol. 103), Journal of
Molecular Evolution (up to Vol. 35), Insect Biochemistry (up to Vol. 22), and Molecular Biology
and Evolution (up to Vol. 9); today, almost all
biochemical journals contain work of this sort, as
the references in this present book testify.
1.2 Uniformity and Diversity
in Biochemistry
All living organisms show extensive correspondence between the structure of their component
molecules and active chemical processes. A part
of this chemical similarity may stem from the fact
that only so is life at all possible. Lehninger refers
vividly to the "molecular logic of the organism".
Even between such different organisms as bacteria and mammals there are many similarities at
the molecular level which cannot be satisfactorily
explained either by functional necessity or by
chance. This is particularly clear in the comparison of nucleic acid and protein sequences. This
homology in the macromolecules carrying information is the strongest evidence for the common
origin of all living organisms. It will be shown that
the enormous number of different proteins can be
arranged into just a few hundred groups of proteins with significant homology (protein superfamilies) which apparently came into being in a
common ancestor during the early development
of life on earth.
In addition to the correspondence arising from
the basic necessities of life and ancestral relationships, there is in fact much variety among all characters of living organisms. On the one hand this is
historically determined: only that which originates de novo always according to the same rules
can be the same. On the other hand the variety of
organisms is related to their complexity: the more
complex living or non-living systems are, the less
likely they are to resemble one another. In all
aspects the variety of living things defies the
imagination. The number of animal species on
the earth can no longer be even reasonably estimated. Over a million animal species have been
described scientifically so far, three-quarters
of them are insects (see Appendix). Until
recently, the real number of species was estimated
by most zoologists to be 3-5 million, but following investigations of the tropical fauna [24] the
figure is now believed to be ten times this. Fur-
1 The Subject Matter and Methods of Comparative Biochemistry
The application of chemical concepts and
methods for investigations of the life processes
led to "physiological chemistry" or "chemical
physiology", which soon became an independent
discipline. The term "biochemistry" was first
introduced by Neuberg in 1903. Also, in biochemistry the comparison of different species
served at first to establish the consistency of basic
principles; . examples include Otto von Fuerth
(1903) in Comparative Chemical Physiology of
Lower Animals [9], and E. Baldwin (1937) in
Introduction to Comparative Biochemistry [1].
Noch (1958) quote Dixon and Webb in their
monograph on enzymes [6]:
"It is a remarkable fact that in general the catalytic properties, specificity, activity, affinities,
etc., of a given enzyme vary little with the source.
Although there may be slight physical differences
in a given enzyme when it is produced by different cells they are usually unimportant, and the
enzyme remains essentially the same enzyme."
In 1895 Emil Fischer had already pointed out
differences between enzymes of different origins.
At first, however, this, together with the species
and tissue specificity of other biochemical characters, was considered to be a methodical impediment to biochemical studies rather than a unique
scientific problem. Credit for emphasizing the
importance of phylogenetic considerations in biochemistry must go to Marcel Florkin with his
book L'evolution biochimique (1944). In his later
works this commendable scientist was also concerned with establishing "comparative biochemistry", as an illustration of the biochemical
diversity of organisms, alongside "general biochemistry", as lessons from the basic principles of
biochemical organization; examples are his book
Unity and Diversity in Biochemistry (1960) and as
editor of the handbooks Comparative Biochemistry (7 volumes 1960-1964, with H. S. Mason)
and Chemical Zoology (11 volumes 1967-1979,
with B. T. Scheer).
In the last two decades, the comparative and
phylogenetic approach to biochemistry has
become rather fashionable. Monographs dealing
with particular animal groups almost invariably
contain sections on comparative biochemistry,
and new monographs and reviews on comparative
biochemical subjects are constantly appearing.
The 13 volumes of Comprehensive Insect Physiology, Biochemistry and Pharmacology, published
simultaneously in 1985, a remarkable achievement by Kerkut and Gilbert, contain many chapters on biochemical themes [20]. Papers with
comparative or phylogenetic aims are not only to
be found in specialist journals, e.g. Comparative
Biochemistry and Physiology: Part B (Biochemistry) (December 1992 to Vol. 103), Journal of
Molecular Evolution (up to Vol. 35), Insect Biochemistry (up to Vol. 22), and Molecular Biology
and Evolution (up to Vol. 9); today, almost all
biochemical journals contain work of this sort, as
the references in this present book testify.
1.2 Uniformity and Diversity
in Biochemistry
All living organisms show extensive correspondence between the structure of their component
molecules and active chemical processes. A part
of this chemical similarity may stem from the fact
that only so is life at all possible. Lehninger refers
vividly to the "molecular logic of the organism".
Even between such different organisms as bacteria and mammals there are many similarities at
the molecular level which cannot be satisfactorily
explained either by functional necessity or by
chance. This is particularly clear in the comparison of nucleic acid and protein sequences. This
homology in the macromolecules carrying information is the strongest evidence for the common
origin of all living organisms. It will be shown that
the enormous number of different proteins can be
arranged into just a few hundred groups of proteins with significant homology (protein superfamilies) which apparently came into being in a
common ancestor during the early development
of life on earth.
In addition to the correspondence arising from
the basic necessities of life and ancestral relationships, there is in fact much variety among all characters of living organisms. On the one hand this is
historically determined: only that which originates de novo always according to the same rules
can be the same. On the other hand the variety of
organisms is related to their complexity: the more
complex living or non-living systems are, the less
likely they are to resemble one another. In all
aspects the variety of living things defies the
imagination. The number of animal species on
the earth can no longer be even reasonably estimated. Over a million animal species have been
described scientifically so far, three-quarters
of them are insects (see Appendix). Until
recently, the real number of species was estimated
by most zoologists to be 3-5 million, but following investigations of the tropical fauna [24] the
figure is now believed to be ten times this. Fur-