ASCOMA ONTOGENY: IS THIS CHARACTER SET OF ANY USE IN THE SYSTEMATICS OF LICHENIZED ASCOMYCETES?

The use of ascoma ontogeny in the systematics of lichenized asco-mycetes is reviewed briefly. Two recently studied examples are discussed to illustrate the use of ontogenetic studies to discover phylogenetic relationships. As one example, theAgyriaceaewas mainly circumscribed by the ascus type and included diverse genera.Xylographais characterized by lirelliform apothecia. However, the ascoma development shares the ontogenetic pattern observed inTrapeliaand its placement in the family was confirmed. In contrast,Anamylopsoraexhibited a substantially different apothecial development and was separated as a family of its own. As a second example, theCandelariaceaeis based on chemical characters. With the detection of pulvinic acid derivatives also in the genusLecanora, the distinction of theCandelariaceaeandLecanoraceaebecame doubtful. Therefore, the ascoma ontogeny was employed to evaluate this classification and is illustrated here in detail forCandelaria fibrosa. The substantial similarity of the ascoma development found in both families suggests that both might be better united. Finally, a general discussion of the significance of ontogenetic characters in lichen taxonomy is included.     

SECTION 1 — MOLECULAR EVOLUTION AND PHYLOGENETICS: GENERAL ISSUES

Plant Molecular Biology -     

IS GREATER FEMALE LONGEVITY A GENERAL FINDING AMONG ANIMALS?

(A) There are data showing beyond question a gender gap, with women living longer than men, especially in economically developed societies. There is greater male vulnerability to the major causes of human death. (B) In lower animals there are data suggesting a female survival advantage to adult life in many species, but the observations do not consider longevity or survival to an advanced age. (C) In laboratory rodents kept under controlled conditions the relationship of sex to longevity is variable, with males sometimes showing greater longevity than females and with life span being dependent on factors like breeding and diet. (D) Similar genetic and hormonal processes operate in humans and in non-human mammals including the genetic mechanism of sex determination, the hormonal consequences of sex determination, and the effects of hormones on processes which affect longevity such as cholesterol levels and immune functions. (E) Causes of death in humans and animals are different, and it seems unlikely, therefore, that the same mechanisms could be determinants of longevity in all mammalian species. (F) Human male and female longevity continue to change, and it is likely that the gender gap will narrow, with societal and medical changes in post-industrial societies reducing the male disadvantages in behaviour and in the handling of cholesterol. (G) It remains an important question whether part of the gender gap seen in humans is based on other differences in the basic biology of males and females.     

SYSTEMATICS OF ISOPTERA FROM CHINA——2. DESCRIPTIONS OF THREE NEW SPECIES OF TERMITIDAE

The present paper deals with 3 new "Capritermes typus" termites belonging toMirocapritermes, Procapritermes and Homallotermes respectively. Holotypes, morphotypes,paratypes and thier duplications are deposited in Huanan Tropical Crops College, Tan-hsien, Hainan Is., China.     

AUDIO COMPUTERS—THEORY OF OPERATION AND GUIDELINES FOR SELECTION OF SYSTEMS AND COMPONENTS

ABSTRACT

Computers are available that can store, synthesize and replay sounds using digital technology. I describe the major components of audio computers, the principles of digital sound acquisition and playback, and information and caveats for scientists interested in acquiring an audio computer system for their own use. A tutorial on analog filter application is also included as well as a diagnostic procedure and a buyer's check list.     

HOW CLOSELY CORRELATED ARE MOLECULAR AND QUANTITATIVE MEASURES OF GENETIC VARIATION? A META‐ANALYSIS

The ability of populations to undergo adaptive evolution depends on the presence of quantitative genetic variation for ecologically important traits. Although molecular measures are widely used as surrogates for quantitative genetic variation, there is controversy about the strength of the relationship between the two. To resolve this issue, we carried out a meta-analysis based on 71 datasets. The mean correlation between molecular and quantitative measures of genetic variation was weak (r = 0.217). Furthermore, there was no significant relationship between the two measures for life-history traits (r = -0.11) or for the quantitative measure generally considered as the best indicator of adaptive potential, heritability (r = -0.08). Consequently, molecular measures of genetic diversity have only a very limited ability to predict quantitative genetic variability. When information about a population's short-term evolutionary potential or estimates of local adaptation and population divergence are required, quantitative genetic variation should be measured directly.     

PHYLOGENY OF THE RUBIACEAE AND THE LOGANIACEAE: CONGRUENCE OR CONFLICT BETWEEN MORPHOLOGICAL AND MOLECULAR DATA?

Phylogenetic analyses of 33 genera of Rubiaceae were performed using morphological and a few chemical characters. Parsimony analysis based on 29 characters resulted in eight equally parsimonious trees, with a consistency index of 0.40 and a retention index of 0.69. These results were compared to a phylogenetic analysis of the same genera based on chloroplast DNA restriction site data. There are discrepancies between the two analyses, but if we consider groupings reflected in the present classification there is much congruency. With the exception of four genera, all the genera are positioned in the same group of taxa in the two analyses. Clades of taxa representing three of the four subfamilies (~the Antirheoideae, ~the Rubioideae, and the ~Ixoroideae) are monophyletic, while the fourth subfamily Cinchonoideae is shown to be paraphyletic. Both analyses support a widened tribe Chiococceae, including the former subtribe Portlandiinae (Condamineeae). Furthermore, in both analyses the tribe Hamelieae is placed outside the subfamily Rubioideae where it is now housed. In search for the most plausible sister group to the Rubiaceae, the genus Cinchona (Rubiaceae) was analyzed together with 13 genera of the Loganiaceae, Nerium (Apocynaceae), and Exacum (Gentianaceae). Cornus (Comaceae), Olea (Oleaceae), and these two genera together were used as outgroups. The analysis, including 25 characters, 16 taxa, and with Cornus and Olea together as an outgroup, resulted in four equally parsimonious trees, with a consistency index of 0.53 and a retention index of 0.62. The non-Loganiaceae taxa Cinchona (Rubiaceae), Nerium (Apocynaceae), and Exacum (Gentianaceae) were all found to have their closest relatives within the Loganiaceae indicating that the Loganiaceae are paraphyletic and ought to be reclassified. As a result of the morphological data the most plausible sister group to the Rubiaceae is the tribe Gelsemieae of the Loganiaceae.