CELL BIOCHEMISTRY AND FUNCTION

Cell Biochem[ Funct[ 07\ 116 "1999#

Copyright Þ 1999 John Wiley + Sons\ Ltd[

Book Review

THE MOLECULAR ORIGINS OF LIFE]ASSEMBLING PIECES OF THE PUZZLE

Andre� Black "Ed[#\ Cambridge University Press\pp[ 306¦viii\ -11[84 "paperback#\ ISBN 941045364\ -54 "hardback#\ ISBN 9 410 45301 2\ "0887#[

Considerations of the origin of life no longer excite theshock\ horror that they did in the 0829s\ when I[B[S[Haldane put forward his ideas on the evolution of livingcells from non!living components[ The aftermath of theRussian revolution has meant that Haldane was unawareof the thoughts of an even earlier ponderer on thesematters * Alexander Oparin in the early 0819s[ The roadfrom there is marked by a few milestones\ amongst themStanley Miller\ a contributor to this volume\ with thelaboratory synthesis of prebiotic organic compounds\and Manfred Eigen\ with the theoretical and exper!imental analysis of the hypercycle[

This volume\ dated 0887 but released early in 0888\ isin _ve parts\ and is noteworthy for a couple of unusualendpieces\ a fourth part looking at the evidence shed onlife|s origins by existing prokaryotes\ notably hyper!thermophiles\ and an examination by William Schopf ofthe current state of evolutionary thought on earlybacteria[ A _fth part is concerned with the conditions forlife on two other worlds\ Titan and Mars[

This book is not exactly bedtime reading and it mighthave been better indexed[ The _rst three parts are packedwith information on the Earth|s early atmosphere\ thee}ects of macro! and micrometeoritic bombardment ofthe early Earth|s surface\ prebiotic chemistry\ hydro!thermal vents\ the development of membrane com!partments\ the supposed pivotal role of iron and sulphurin the evolution of metabolism\ and\ inevitably\ the devel!opment of the presumed RNA world which began the_rst information revolution[ Those who give a few throw!

away lectures on the subject to _nal year undergraduatesneed look no further than this tome[

That said\ there are some notable omissions[ It hasalways been di.cult to see how the cocktail of organicchemicals synthesized in the way observed and describedby Miller could precede the rather limited number ofcompounds which actually participate in metabolism[How were the metabolically active materials selected out<And how were those early cycles of metabolism and rep!lication segregated within or from the pervasive prebioticsoup\ of which\ incidently\ absolutely no trace has everbeen found< Cairns!Smith|s ideas on a mineral!basedgenetic origin\ which might answer these and other con!undrums\ are dismissed by the editor for lack of exper!imental evidence\ a strange charge in a _eld where\ as theeditor himself states\ Earth|s turbulent geological historyhas obliterated any direct clues[ Nor does the chapter onhydrothermal systems note that at the bottom of theHadean ocean where thermal vents might have come andgone\ the likely remnants of the vents\ hollow cylindricalor conical mineral deposits\ might make a vast array ofinteresting microenvironments for some relevant chem!istry[ And the chapter on the origin of life in an ironÐsulphur world makes no mention of recent proposalsthat early cells were surrounded by ferric hydroxide gelmembranes\ derived from alkaline oceanic vents exudinginto an acidic iron!rich sea[ It|s all speculation;

Not that there is anything wrong with that[ The volumeis stimulating\ if a little iconoclastic in its choice ofsubjects[ Titan seems a less likely source of extraterrestirallife than the Jovian moons\ Europa and Io[ And as othershave remarked\ there is an awful lot at stake in the lifeon Mars theory\ not least at NASA\ whence the authorof this chapter hails[ But the book is well!produced\ well!edited and the paperback edition excellent value[

JOHN MARSDEN