| Micro-complement fixation: a quantitative estimator of protein evolution | RD Maxson, LR Maxson | 375 |
| Maintenance of the cellobiose utilization genes of Escherichia coli in a cryptic state | BG Hall, PW Betts, M Kricker | 389 |
| Estimating the reliability of evolutionary trees | D Penny, M Hendy | 403 |
| Simple methods for estimating the numbers of synonymous and nonsynonymous nucleotide substitutions | M Nei, T Gojobori | 418 |
| Paenungulata: a comparison of the hemoglobin sequences from elephant, hyrax, and manatee | T Kleinschmidt, J Czelusniak, M Goodman, G Braunitzer | 427 |
| Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: I. Sequence of trpG encoding the glutamine amidotransferase subunit | IP Crawford, L Eberly | 436 |
| Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli | IP Crawford, A Wilde, EM Yelverton, D Figurski, RW Hedges | 449 |
| Book reviews | S Yokoyama, RD Sage | 459 |
| Errata: Evolutionary history of the hybridogenetic hybrid frog Rana esculenta as deduced from mtDNA analyses | C Spolsky, T Uzzell | 463 |
