Aim The aim of the current study is to conduct a comprehensive phylogenetic analysis of the genus Arbacia to elucidate the evolution and phylogenetic relationships among all extant species and reevaluate the presence of geographic structure within species that have wide, fragmented distributions. Location Specimens of Arbacia were collected from 34 localities spanning the Atlantic and Pacific Oceans, and the Mediterranean Sea....

Aim To test hypothesized biogeographic partitions of the tropical Indo‐Pacific Ocean with phylogeographic data from 56 taxa, and to evaluate the strength and nature of barriers emerging from this test. Location The Indo‐Pacific Ocean. Time period Pliocene through the Holocene. Major taxa studied Fifty‐six marine species. Methods We tested eight biogeographic hypotheses for partitioning of the Indo‐Pacific using a novel modific...

Aim The goatfish genus M ulloidichthys is abundant on reefs throughout the tropics. Characteristic of this genus is a long larval and pelagic juvenile phase, which could potentially confer large dispersal capacity. We sampled its mitochondrial DNA to answer the following questions: What speciation events have led to the formation of the extant species? How do they correlate with geological and oceanographic events? Are M . den...

Land is not the only barrier to dispersal encountered by marine organisms. For sedentary shallow water species, there is an additional, marine barrier, 5000 km of uninterrupted deep‐water stretch between the central and the eastern P acific. This expanse of water, known as the ‘ E astern P acific B arrier’, has been separating faunas of the two oceanic regions since the beginning of the C enozoic. Species with larvae that cann...

Among shallow water sea urchin genera, Arbacia is the only genus that contains species found in both high and low latitudes. In order to determine the geographical origin of the genus and its history of speciation events, we constructed phylogenies based on cytochrome oxidase I and sperm bindin from all its species. Both the mitochondrial and the nuclear gene genealogies show that Arbacia originated in the temperate zone of th...

A latitudinal gradient in biodiversity has existed since before the time of the dinosaurs, yet how and why this gradient arose remains unresolved. Here we review two major hypotheses for the origin of the latitudinal diversity gradient. The time and area hypothesis holds that tropical climates are older and historically larger, allowing more opportunity for diversification. This hypothesis is supported by observations that tem...

Echinometra is a pantropical sea urchin made famous through studies of phylogeny, speciation, and genetic structure of the Indo‐West Pacific (IWP) species. We sequenced 630 bp of the cytochrome oxidase I (COI) mitochondrial gene to provide comparable information on the eastern Pacific and Atlantic species, using divergence between those separated by closure of the Isthmus of Panama 3.1 million years ago (Ma) to estimate dates...