Adaptation that increases tolerance to high hydrostatic pressure and low temperature allows colonisation of abyssal depths and reduces the stress evolution response, consequently returning speciation of deeper taxa to the background rate.
Adaptation that increases tolerance to high hydrostatic pressure and low temperature allows colonisation of abyssal depths and reduces the stress evolution response, consequently returning speciation in deeper taxa to the background rate.
Cases of deep intraspecific divergence (Table 4) can reflect misidentifications, cryptic taxa, ancestral polymorphisms, or introgression.
The direction of the host switch within plasmodiophorids is equivocal, because of the unresolved branching order of the deep branching taxa, including Woronina.
However, given that the insertion is present in some of the deep branching taxa, but not in all euryarchaea, implies there was at least one secondary loss of this insertion.
The present study has aimed to place deep-sea nematode species into a phylogenetic framework, investigate relationships between shallow water and deep-sea taxa, and elucidate phylogeographic patterns amongst the deep-sea fauna.
Within the Janiroidea, there is evidence supporting the radiation of shallow-water isopods into deeper habitats through isothermal water columns [ 7], reinvasions of shallow habitats by deep-sea taxa [ 7, 8], and multiple independent colonizations of the deep-sea [ 9]--thus, deep-sea taxa within this group probably represent ancient evolutionary lineages that split off early from other taxa [ 10].
Few studies have investigated historical depth transitions between shallow- and deep-reef taxa.
The mesophotic reef-fish fauna at Curaçao does not transition directly to one composed of deep-sea taxa.
Thus, deep-sea taxa contribute little to the rariphotic reef-fish assemblage at Curaçao, which is dominated overwhelmingly by primarily altiphotic and mesophotic families.
