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E M Jope

Publications and source records attributed to E M Jope.

3 recordsLinked to original sources

The emergence of man: information from protein systems.

Protein amino acid sequences are not directly informative about the emergence of man from his immediate primate ancestry. But this could be because too little attention has been given to protein systems most relevant to the progress of hominization, those that, through their cell-surface action or enzymatic control of biosynthesis of other key proteins or hormones, can modulate the course of cell and tissue development, and so determine changes in tooth architecture, bone and tissue structure, brain and nerve cell development, etc. There are also the histones and other proteins associated with DNA in the genetic material, which have some modulating influence on gene expression. The whole process of carrying information from the genetic material to a species-reproducible morphology is through a cascade of multiple interlocking systems involving proteins at every turn. It is through changes in balance within these systems, and subsequent selection pressures, that the modulations of primate morphology and behaviour that constitute hominization have proceeded, and the process must be understood in terms of cytobiochemistry to give a fully detailed information of the evolving human genome.

Amino Acid Sequence

The evolution of plants and animals under domestication: the contribution of studies at the molecular level.

Protein molecules are essential catalysts in life processes and also form much of the substance of living material. Their three dimensional structures determine their biological function. Their biosynthesis is primarily determined by arrays of nucleic acid macromolecules (DNA and RNA), and the amino acid sequences that constitute their long spatially organized peptide-chain molecules reflect at one remove this DNA coding system, and thus record a step-by-step history of some of the viable genetic events (natural or man-controlled) that have created the organism and the breed. Amino acid sequences can be used to trace the progress of controlled breeding in two ways: by extrapolation back from living breeds, and by analysis of ancient protein material. Of the latter, bone or tendon or skin collagens and hair keratins are the most perfectly preserved as molecular structures through 20,000 years and indeed much longer. Amino acid sequences are expensive to determine (collagen has 1052 amino acid residues), and the potential of this palaeobiological information has been as yet little exploited. The first approach has, however, been more explored, in both plants and animals. Several protein systems must be studied in conjunction to reveal the phylogenetic threads in any one breed. As the three dimensional quaternary structure of protein molecules becomes more appreciated in relation to biological function, and as new techniques and procedures are developed, amino acid sequence data can become more informative in our ultimate understanding of early selective breeding.

Amino Acid Sequence