1 The SUbject Matter and Methods
of Comparative Biochemistry
1.1
Historical Development of the Comparative
Approach in Biology
1.2
Uniformity and Diversity in Biochemistry
1.3
The Subjects of Comparative Biochemistry
1.3.1 Comparison of Low Molecular Weight Substances
1.1 Historical Development of the
Comparative Approach in Biology
The diversity of living organisms, the abundance
of forms, colours and phenotypes, is one of the
most impressive aspects of our world. Since
ancient times, science has concerned itself with
the ordering and classification of this diversity. At
first, only those structures and processes which
were recognizable without any special apparatus
could be compared; the invention of the light
microscope and the electron microscope introduced new dimensions and new opportunities for
comparison. Finally, progress to the molecular
level became possible with the development of
methods of biochemical analysis. Different comparative biological disciplines arose, each with
particular goals and methods. The oldest, taxonomy, is concerned with the classification of species; this was originated by Aristotle, and is
represented most importantly by the work of
Carolus Linnaeus (1707-1778).
The binomial nomenclature suggested by Linnaeus, in which each organism is denoted by a
genus and species name in Latin, is today considered obligatory. The denotation is completed by
attachment of the name of the first user; the "L."
that one finds at the end of many plant and animal names stems from the descriptions in Linnaeus' Systema Naturae (1735). Until the eighteenth century, the philosophical basis of taxonomy was the idealistic concept of a "Scala Naturae", a ladder reaching from the "lower organisms" up to man as the "crown of creation". In
1.3.2 Comparison of Information-Carrying
Macromolecules
1.4
Chance and Necessity in Molecular Evolution
1.4.1 Non-Adaptive ("Neutral") Differences
1.4.2 Molecular Adaptation
References
the nineteenth century, the idea of evolution, the
assumption of genealogical relationships between
organisms, found increasing acceptance.
The second comparative biological discipline,
comparative anatomy, analyses the outer and
inner structures of animals. This originated from
medicine where comparisons were made between
animal organs and those of man; the term "comparative anatomy" was coined by the doctor
Nehemiah Grew in 1675. Since Cuvier (17691832), comparative anatomy has become a discipline of zoology which was remarkably consolidated in the nineteenth century and, with the distinction between homology and analogy, provided the most important tool for phylogenetic
analysis. There were similar developments in
botany but these will not be covered in this present zoological text.
The comparative physiology of animals also
had its origins in medicine. Because, of course,
few experiments are possible on people, human
physiology relied, and still relies today, on various
animal model systems. The extrapolation of
results from animals to the human situation is
ensured by the growing appreciation of the universal validity of the "ground rules" of general
physiology. With the extent to which invertebrates were included in physiological experiments,
there grew the realization that the conformity of
life processes to several basic principles is overlayered by a confusing variety of detail. In this
respect, a significant contribution was made with
the improved possibilities for experiments on
marine invertebrates at the Naples Zoology Station, founded in 1870 by Anton Dohrn.
of Comparative Biochemistry
1.1
Historical Development of the Comparative
Approach in Biology
1.2
Uniformity and Diversity in Biochemistry
1.3
The Subjects of Comparative Biochemistry
1.3.1 Comparison of Low Molecular Weight Substances
1.1 Historical Development of the
Comparative Approach in Biology
The diversity of living organisms, the abundance
of forms, colours and phenotypes, is one of the
most impressive aspects of our world. Since
ancient times, science has concerned itself with
the ordering and classification of this diversity. At
first, only those structures and processes which
were recognizable without any special apparatus
could be compared; the invention of the light
microscope and the electron microscope introduced new dimensions and new opportunities for
comparison. Finally, progress to the molecular
level became possible with the development of
methods of biochemical analysis. Different comparative biological disciplines arose, each with
particular goals and methods. The oldest, taxonomy, is concerned with the classification of species; this was originated by Aristotle, and is
represented most importantly by the work of
Carolus Linnaeus (1707-1778).
The binomial nomenclature suggested by Linnaeus, in which each organism is denoted by a
genus and species name in Latin, is today considered obligatory. The denotation is completed by
attachment of the name of the first user; the "L."
that one finds at the end of many plant and animal names stems from the descriptions in Linnaeus' Systema Naturae (1735). Until the eighteenth century, the philosophical basis of taxonomy was the idealistic concept of a "Scala Naturae", a ladder reaching from the "lower organisms" up to man as the "crown of creation". In
1.3.2 Comparison of Information-Carrying
Macromolecules
1.4
Chance and Necessity in Molecular Evolution
1.4.1 Non-Adaptive ("Neutral") Differences
1.4.2 Molecular Adaptation
References
the nineteenth century, the idea of evolution, the
assumption of genealogical relationships between
organisms, found increasing acceptance.
The second comparative biological discipline,
comparative anatomy, analyses the outer and
inner structures of animals. This originated from
medicine where comparisons were made between
animal organs and those of man; the term "comparative anatomy" was coined by the doctor
Nehemiah Grew in 1675. Since Cuvier (17691832), comparative anatomy has become a discipline of zoology which was remarkably consolidated in the nineteenth century and, with the distinction between homology and analogy, provided the most important tool for phylogenetic
analysis. There were similar developments in
botany but these will not be covered in this present zoological text.
The comparative physiology of animals also
had its origins in medicine. Because, of course,
few experiments are possible on people, human
physiology relied, and still relies today, on various
animal model systems. The extrapolation of
results from animals to the human situation is
ensured by the growing appreciation of the universal validity of the "ground rules" of general
physiology. With the extent to which invertebrates were included in physiological experiments,
there grew the realization that the conformity of
life processes to several basic principles is overlayered by a confusing variety of detail. In this
respect, a significant contribution was made with
the improved possibilities for experiments on
marine invertebrates at the Naples Zoology Station, founded in 1870 by Anton Dohrn.