Wm. J. Woelkerling

Bio: Wm. J. Woelkerling is an academic researcher from La Trobe University. The author has contributed to research in topics: Corallinaceae & Conceptacle. The author has an hindex of 33, co-authored 60 publications receiving 2700 citations.

Growth-forms in non-geniculate coralline red algae (Corallinales, Rhodophyta)

Abstract: Although differences in growth-form have been widely used in delimiting taxa of non-geniculate coralline red algae (Corallinales, Rhodophyta), there has been no consistent application of the more than 100 terms employed to describe the growth-forms present, and considerable confusion has resulted. This study of over 5000 populations of non-geniculate corallines from all parts of the world has shown that an intergrading network of growth-forms with 10 focal points is present: unconsolidated, encrusting, warty, lumpy, fruticose, discoid, layered, foliose, ribbon-like and arborescent. This focal point terminology can be used to describe any specimen or species of non-geniculate coralline in a consistent, easily interpretable manner. Details of the system are provided, the relationships of the system to past proposals are discussed, and the extent to which differences in growth-forms can be used as taxonomic characters in the non-geniculate Corallinales is reviewed.

Marine epibiosis. I. Fouling and antifouling: some basic aspects

Abstract: In the marine environment any solid, exposed undefended surface will become fouled. Similarly, fouling may effect numerous species which are able to tolerate a certain degree of epibiosis. In contrast, many others actively maintain t h e ~ r body surface clean of epibionts ('antifouling'). This paper illustrates aspects of the epibiosis/antifouling complex and discusses the omnipresence of fouling pressure, the first stages in the establishment of a fouhng community, the benefits and disadvantages of epibiosis for both epiand basibionts, and possible anbfouling defense adaptations.

Green algae and the origin of land plants

Abstract: Over the past two decades, molecular phylogenetic data have allowed evaluations of hypotheses on the evolution of green algae based on vegetative morphological and ultrastructural characters. Higher taxa are now generally recognized on the basis of ultrastructural characters. Molecular analyses have mostly employed primarily nuclear small subunit rDNA (18S) and plastid rbcL data, as well as data on intron gain, complete genome sequencing, and mitochondrial sequences. Molecular-based revisions of classification at nearly all levels have occurred, from dismemberment of long-established genera and families into multiple classes, to the circumscription of two major lineages within the green algae. One lineage, the chlorophyte algae or Chlorophyta sensu stricto, comprises most of what are commonly called green algae and includes most members of the grade of putatively ancestral scaly flagellates in Prasinophyceae plus members of Ulvophyceae, Trebouxiophyceae, and Chlorophyceae. The other lineage (charophyte algae and embryophyte land plants), comprises at least five monophyletic groups of green algae, plus embryophytes. A recent multigene analysis corroborates a close relationship between Mesostigma (formerly in the Prasinophyceae) and the charophyte algae, although sequence data of the Mesostigma mitochondrial genome analysis places the genus as sister to charophyte and chlorophyte algae. These studies also support Charales as sister to land plants. The reorganization of taxa stimulated by molecular analyses is expected to continue as more data accumulate and new taxa and habitats are sampled. Twenty years ago, a relatively slim volume with chapters by leading chlorophycologists celebrated the systematics of green algae (Irvine and John, 1984), a field that was undergoing rapid and fascinating changes, both in content and theory. ‘‘The present period may be termed the ‘Age of Ultrastructure’ in green algal systematics,’’ wrote Frank Round (1984, p. 7) in the introductory chapter, which summarized the history and state of the art. Round (1984) argued that light microscopy had laid the foundation in the preceding two centuries, but that the foundation was largely descriptive—alpha taxonomy in the most restricted sense. Ultrastructure, he asserted, had enlarged and presumably would continue to expand our horizons to unify systematics of green algae and overcome the fragmented alpha taxonomy that had dominated the field. Little did Round know that this golden age of green algal systematics was about to go platinum. Molecular systematics, in concert with a rigorous theoretical approach to data analysis and hypothesis testing (Theriot, 1992; Swofford et al., 1996), would at first complement and then transform the age of ultrastructure and usher in the ‘‘Age of Molecules.’’ In this article, we review the major advances in green algal systematics in the past 20 years, with a focus on well-supported, monophyletic taxa and the larger picture of phylogeny and evolution of green algae. We will review the types of data that have fueled these advances. As will become obvious, this perspective entails discussion of some embryophytes as well as their closest green algal relatives. In addition, we will point