Two hypotheses for the early radiation of the metazoans are vividly discussed in recent
phylogenomic studies, the 'Porifera-first'hypothesis, which places the poriferans as the sister …

Despite long-standing experimental interest in ctenophores due to their unique biology,
ecological influence and evolutionary status, previous work has largely been constrained by …

The phylogenetic placement of the morphologically simple placozoans is crucial to
understanding the evolution of complex animal traits. Here, we examine the influence of …

Organs that pump luminal fluids by the coordinated beat of motile cilia are integral to animal
physiology. Such organs include the human airways, brain ventricles and reproductive …

Digestive systems and extracellular digestion are key animal features, but their emergence
during early animal evolution is currently poorly understood. As the last common ancestor of …

It is widely held that the bilaterian tubular gut with mouth and anus evolved from a simple gut
with one major gastric opening. However, there is no consensus on how this happened. Did …

There is more than one way to develop neuronal complexity, and animals frequently use
different molecular toolkits to achieve similar functional outcomes (= convergent evolution) …

Ctenophores are a group of predatory macroinvertebrates whose controversial phylogenetic
position has prompted several competing hypotheses regarding the evolution of animal …

Our understanding of vertebrate origins and the backbone of human history evolves with
each new fossil find and DNA map. Many species have now had their genomes sequenced …

Cnidarians diverged very early in animal evolution; therefore, investigations of the
morphology and trophic levels of early fossil cnidarians may provide critical insights into the …