New sea urchin phylogeography reveals latitudinal shifts associated with speciation.

摘要: Where do new species arise? When they form and how diverge from a common ancestor? A comprehensive study of Arbacia sea urchins provides surprising answers to these questions. By combining mtDNA phylogeographic markers with nuclear locus(encoding the sperm acrosomal protein bindin) known be susceptible high rates adaptive codon evolution, Lessios et al. (2012) show that lineages arose relatively recently, most often in association latitudinal shifts between temperate zones tropics, one case, significant geological barrier gene flow (the rise Isthmus Panama). In addition 'where' 'when' speciation, data resolve an important question about 'who' are by revealing extensive allele sharing at both loci pair broadly sympatric nominal (that should perhaps considered single taxon). 'How' each other is less easily resolved: there no evidence for reinforcement (via selection on as source divergence species, few decide among alternative hypotheses explain speciation.