Large-scale transitions between alternative states in ecosystems are known as regime shifts. Once described as healthy and dominated by various marine predators, the Black Sea ecosystem by the late 20th century had experienced anthropogenic impacts such as heavy fishing, cultural eutrophication, and invasions by alien species. We studied changes related to these "natural experiments" to reveal ...

Genes for the family of green-fluorescent proteins (GFPs) have been found in more than 100 species of animals, with some species containing six or more copies producing a variety of colours. Thus far, however, these species have all been within three phyla: Cnidaria, Arthropoda and Chordata. We have discovered GFP-type fluorescent proteins in the phylum Ctenophora, the comb jellies. The ctenoph...

Elucidating relationships among early animal lineages has been difficult, and recent phylogenomic analyses place Ctenophora sister to all other extant animals, contrary to the traditional view of Porifera as the earliest-branching animal lineage. To date, phylogenetic support for either ctenophores or sponges as sister to other animals has been limited and inconsistent among studies. Lack of ag...

We studied the evolutionary relationships among basal metazoan lineages by using complete large subunit (LSU) and small subunit (SSU) ribosomal RNA sequences for 23 taxa. After identifying competing hypotheses, we performed maximum likelihood searches for trees conforming to each hypothesis. Kishino-Hasegawa tests were used to determine whether the data (LSU, SSU, and combined) reject any of th...

Explaining variability in offspring vs. adult size among groups is a necessary step to determine the evolutionary and environmental constraints shaping variability in life history strategies. This is of particular interest for life in the ocean where a diversity of offspring development strategies is observed along with variability in physical and biological forcing factors in space and time. W...

SYNOPSIS. In comparative studies using model organisms, extant taxa are often referred to as basal. The term suggests that such taxa are descendants of lineages that diverged early in the history of some larger taxon. By this usage, the basal metazoans comprise just four phyla (Placozoa, Porifera, Cnidaria, and Ctenophora) and the large clade Bilateria. We advise against this practice because b...