Evolving multicellularity is easy, especially in phototrophs and osmotrophs whose multicells
feed like unicells. Evolving animals was much harder and unique; probably only one …

The relationships at the root of the animal tree have proven difficult to resolve, with the
current debate focusing on whether sponges (phylum Porifera) or comb jellies (phylum …

Understanding how complex traits, such as epithelia, nervous systems, muscles, or guts,
originated depends on a well-supported hypothesis about the phylogenetic relationships …

After years of intense research using structural, biological, and biochemical experimental
procedures, it is clear that myosin molecules are essential for striated muscle contraction …

Genomes and transcriptomes are now typically sequenced by individual laboratories but
analyzing them often remains challenging. One essential step in many analyses lies in …

The opsin gene family encodes key proteins animals use to sense light and has expanded
dramatically as it originated early in animal evolution. Understanding the origins of opsin …

Electron microscope studies have shown that the switched-off state of myosin II in muscle
involves intramolecular interaction between the two heads of myosin and between one head …

Phylogenetic relationships among the squids and cuttlefishes (Cephalopoda:
Decapodiformes) have resisted clarification for decades, despite multiple analyses of …

The origin of ctenophores (comb jellies) is obscured by their controversial phylogenetic
position, with recent phylogenomic analyses resolving either sponges or ctenophores as the …

Systematic bias is one of the major phylogenetic issues arising over the last two decades.
Using methods designed to reduce compositional and rate heterogeneity, hence systematic …