Defining species in an advanced technological landscape.

The answer to the proffered question, "What is a species?" is considered one of the fundamental issues of biological science, as well as one of the most polarizing and sometimes acrimonious problems. Dozens of species concepts have been defined, but none are universal for implementation across all taxa. Within the past thirty years, the ability to analyze DNA data has progressed to the point that multiple methodologies can be simultaneously applied to the same evolutionary questions. The use of restriction fragment length polymorphisms, microsatellites, and mitochondrial (mtDNA) and nuclear DNA (nucDNA) sequence data has unarguably changed how we look at diversity and intensified the concept debate through the proliferation of species descriptions. Over the past two decades, Madagascar's biodiversity has gone through a tremendous taxonomic expansion by the elevation of subspecies to species and through novel descriptions, especially within the nocturnal lemurs. With the tremendous continuous loss of habitat, exponential human population growth, and stochastic changes predicted over coming decades, elucidating the earth's biodiversity will never be more important than now. Here, we examine species concepts and their attendant criteria. We predict how technological advances will alter, improve and, we hope, fully consolidate the unity of thoughts related to this central topic of evolutionary biology and its numerous interconnected disciplines.

Contrasting the Practices of Virus Isolation and Characterization between the Early Period in History and Modern Times: The Case of Japanese Encephalitis Virus.

Japanese encephalitis is a serious disease transmitted by mosquitoes. With its recent spread beyond the traditional territory of endemicity in Asia, the magnitude of global threat has increased sharply. While much of the current research are largely focused on changing epidemiology, molecular genetics of virus, and vaccination, little attention has been paid to the early history of virus isolation and phenotypic characterization of this virus. In this review, using this piece of history as an example, I review the transition of the concept and practice of virus isolation and characterization from the early period of history to modern times. The spectacular development of molecular techniques in modern times has brought many changes in practices as well as enormous amount of new knowledge. However, many aspects of virus characterization, in particular, transmission mechanism and host relationship, remain unsolved. As molecular techniques are not perfect in all respects, beneficial accommodation of molecular and biologic data is critically important in many branches of research. Accordingly, I emphasize exercising caution in applying only these modern techniques, point out unrecognized communication problems, and stress that JE research history is a rich source of interesting works still valuable even today and waiting to be discovered.

Fertility depression among cheese-making Penicillium roqueforti strains suggests degeneration during domestication.

Genetic differentiation occurs when gene flow is prevented, due to reproductive barriers or asexuality. Investigating the early barriers to gene flow is important for understanding the process of speciation. Here, we therefore investigated reproductive isolation between different genetic clusters of the fungus Penicillium roqueforti, used for maturing blue cheeses, and also occurring as food spoiler or in silage. We investigated premating and postmating fertility between and within three genetic clusters (two from cheese and one from other substrates), and we observed sexual structures under scanning electron microscopy. All intercluster types of crosses showed some fertility, suggesting that no intersterility has evolved between domesticated and wild populations despite adaptation to different environments and lack of gene flow. However, much lower fertility was found in crosses within the cheese clusters than within the noncheese cluster, suggesting reduced fertility of cheese strains, which may constitute a barrier to gene flow. Such degeneration may be due to bottlenecks during domestication and/or to the exclusive clonal replication of the strains in industry. This study shows that degeneration has occurred rapidly and independently in two lineages of a domesticated species. Altogether, these results inform on the processes and tempo of degeneration and speciation.