Treatment of Particular Topics. Thus Markert Illustrates Some of the Done

Home , Directional selection, Dominance (genetics)

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MENDELCENTENARY: GENETICS, DEVELOPMENT AND EVOLUTION (Proceedings of a Symposium held at the Catholic University of America, November 3rd, 1965). Edited by Roland M. Nardone. The Catholic University of America Press, Washington. pp. 174+v. Thismemorial volume, published rather belatedly nearly three years after the event, contains seven short essays and a translation (the same one as in Bateson's Mendel's Principles of Heredity) of Mendel's famous paper. The essays are mostly aimed at a non-specialist audience, but some of them will be interesting to professional geneticists by virtue of their detailed treatment of particular topics. Thus Markert illustrates some of the problems and ideas concerning the regulation of gene activity in higher organisms by reference to lactate dehydrogenase isozymes and Bolton discusses the determination of homologies between DNA of different species using hybridisation techniques. Both these contributions are profusely illustrated (all the speaker's slides seem to have been reproduced) and are sufficiently detailed to be useful references, though much more has been done on DNA hybridisation since 1965. Among other contributors, Davidson discusses the use of numerical scores based on multiple characters in the disentanglement of difficult taxonomic groups, and Dorothea Bennett uses the Tailless series of alleles in the mouse to show how the analysis of the developmental basis of genetic abnormalities can aid understanding of normal development. Lewontin's essay on the gene and evolution presents ideas rather than information. It contains a thoughtful and thought-provoking assessment of the genetic and physiological advantages of the diploid way of life. Nardone's summary of molecular biology in relation to the origin of life seems, in contrast, rather elementary and second-hand, though it may have been correctly judged for the audience. The final assay, by Conway Zirkie, on Mendel and his era, is most interesting in its assessment of the reasons for the neglect of Mendel's work. All in all this is a volume which I am glad to have though I would probably not have bought it. It would be worth recommending for purchase by a library though not, perhaps, as a high priority. J. R. S. FINCHAM Department of Genetics University of Leeds

DICTIONARYAND ENCYCLOPAEDIA A Dictionary of Genetics by Robert C. King. Oxford University Press. 1968. 291 pp. 34s. A Glossary of Genetics and Cytogenetics by R. Rieger, A. Michaelis and M. M. Green. George Allen & Unwin. 1968. 507 pp. £7. Thesetwo books, though apparently similar, are really very different in aim, for the less expensive paperback is a dictionary and the very expensive hardback is an encyclopaedia. Browsing through them looking for items in my own field of interest, I find they are also different in another respect. The dictionary is often misleading, the encyclopaedia is usually excellent. To illustrate this I quote a few comparative examples: (1) Dominant King: "A gene is called dominant if its phenotypic effect is the same in the heterozygous as in the homozygous condition." 334 REVIEWS Rieger et al.: "Of genetically controlled characters and the cor- responding alleles which are manifest in all heterozygous, hetero- caryotic or heterogenotic members .. . (of)a cross between two homozygous strains. .. ." "Dominanceand recessiveness are not properties of the gene per se Followed by definitions of complete dominance, semi dominance, dominance modifiers, etc., and a reference to dominance deviation. (2) Epistasis King only gives a definition of classical epistasis. Rieger et al. also refer to epistatic deviation in the biometrical sense.

(3) Quantitative inheritance King: "Inheritance of a quantitative character which depends upon the cumulative action of many genes, each of which produces a small effect." Rieger et al.: "Thesecharacters are controlled by many genes with small individual contributions. .. . Theyalmost invariably show a large environmental component of variation." (Each of these definitions is too restrictive but at least the second mentions the environmental component.)

(4) Disruptive selection King: "Theselection of divergent phenotypic extremes in a population until, after several generations, two discontinuous strains are obtained." Rieger et al.: "Simultaneously favours more than one optimum. The favoured genotypes are maintained in a state of polymorphic equilibrium." (King's definition is of divergent directional selection, rather than disruptive selection.) (5) Founder principle King: "The principle that, when a newly isolated population is established, its gene pooi soon diverges from that of the parent population because of sampling errors." Rieger et al.: "The concept that evolutionary divergence may be hastened when a small population invades a new area. This is due not only to the new and probably different selection pressures but also to the fact that a small population includes, due to sampling, only a limited fraction of the total genetic variation of the parent population." (6) Position effect Strangelyenough neither book deals really satisfactorily with this important concept. King does not include Cis-Trans position effects under this heading. Rieger et al. do, but do not mention Bar: they do however refer to Sturtevant 1925.

These few examples should suffice to indicate that the definitions in King's book have not the same quality as those in the larger book, and that the reason for this is not only that King has had less space. It seems that REVIEWS 335

he has spent less time carefully considering his definitions to ensure that they shall not mislead. Apart from the many chemical formulae and the lists of species King provides, the book by Rieger et al. is also far more comprehensive, gives source references for the terms defined, and, where the authors have thought it necessary, sets the definitions into a brief and usually excellent summary of the phenomena involved, often with diagrams. I do not think the Dictionary is to be strongly recommended. On the other hand the Glossary is a remarkable work of scholarship on which the authors are to be congratulated. It would provide a most valuable source book of information, a corrective to the misuse of words, misconception of meanings, and, if regularly referred to, a most useful book for teachers, students and authors. It is a pity it is so expensive. J. M. THODAY Department of Genetics University of Cambridge

BOOKSRECEIVED RESEARCH IN MUSCULAR DYSTROPHY: PROCEEDINGS OF THE 4th SYMPOSIUM, Jan. 1968. Pitman Medical Pub. Co. Ltd. 1968. Pp. 472. 60s. PROTOZOOLOGIE: 2 AUFLAGE. K. G. Grell. Springer-Verlag. 1968. Pp. 511. DM 98. CURRENT TOPICS IN MICROBIOLOGY AND IMMUNOLOGY. Vol. 42. INSECT VIRUSES. K. Maramorosch (ed.). Springer-Verlag. 1968. Pp. 192. DM 36. CURRENT TOPICS IN MICROBIOLOGY AND IMMUNOLOGY. Vol. 43. Springer-Verlag. 1968. Pp. 233. DM 49.60. ACTA AGRONOMICA ACADEMIAE SCIENTARIUM HUNGARICAE XVII, 1-2. Akademiai Kiado, Budapest. 1968. Pp. 289. IMMUNBIOLOGISCHE UNTERSUCHUNGEN BEI PRIMATEN. J. Schmitt. S. Karger ag Basel. 1968. Pp. 146. 70s. PRINCIPLES OF INSECT CHEMO-STERILISATION. G. C. Labrecque and C. N. Smith. The North-Holland Publishing Co., Amsterdam. 1968. Pp. 354. 152s. MARINE MAMMALS. Richard J. Harrison and Judith E. King. 1-Jutchinson University Library. 1968. Pp. 192. Paperback, us. 6d.; Fullbound, 27s. 6d. CURRENT PROBLEMS OF LOWER VERTEBRATE PHYLOGENY. Tor John Wiley & Sons. 1968. Pp. 539. 328s.