TY - JOUR
T1 - Hierarchical biogeographical processes largely explain the genomic divergence pattern in a species complex of sea anemones (Metridioidea: Sagartiidae: Anthothoe)
AU - Spano, Carlos A.
AU - Häussermann, Vreni
AU - Acuña, Fabián H.
AU - Griffiths, Charles
AU - Seeb, Lisa W.
AU - Gomez-Uchida, Daniel
N1 - Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2018/10
Y1 - 2018/10
N2 - The phylogenetic resolution provided by genome-wide data has demonstrated the usefulness of RAD sequencing to tackle long-standing taxonomic questions. Cnidarians have recently become a model group in this regard, yet species delimitation analyses have been mostly performed in octocorals. In this study, we used RAD sequencing to test the species hypotheses in a wide-spread complex of sea anemones (genus Anthothoe), contrasting this new line of evidence with their current classification. The alternative hypotheses were tested using a Bayes Factors delimitation method, and the most probable species tree was then evaluated under different biogeographic scenarios. Our results decisively rejected the current morphology-informed delimitation model and infer the presence of several cryptic species associated with distinct marine ecoregions. This spatial pattern was remarkably consistent throughout the study, highlighting the role of geographic distribution as a powerful explanatory variable of lineages diversification. The southern Gondwana pattern with episodic, jump dispersal events is the biogeographic historical representation that best fits the Anthothoe species tree. The high population differentiation possibly amplified by the occurrence of asexual reproduction makes it difficult to identify genes responsible for local adaptation, however, these seem to be mainly associated with cellular and metabolic processes. We propose a new set of species hypotheses for the Southern Hemispheric Anthothoe clade, based on the pronounced genomic divergence observed among lineages. Although the link between the genetic and phenotypic differentiation remains elusive, newer sequencing technologies are bringing us closer to understanding the evolution of sea anemone diversity and, therefore, how to appropriately classify them.
AB - The phylogenetic resolution provided by genome-wide data has demonstrated the usefulness of RAD sequencing to tackle long-standing taxonomic questions. Cnidarians have recently become a model group in this regard, yet species delimitation analyses have been mostly performed in octocorals. In this study, we used RAD sequencing to test the species hypotheses in a wide-spread complex of sea anemones (genus Anthothoe), contrasting this new line of evidence with their current classification. The alternative hypotheses were tested using a Bayes Factors delimitation method, and the most probable species tree was then evaluated under different biogeographic scenarios. Our results decisively rejected the current morphology-informed delimitation model and infer the presence of several cryptic species associated with distinct marine ecoregions. This spatial pattern was remarkably consistent throughout the study, highlighting the role of geographic distribution as a powerful explanatory variable of lineages diversification. The southern Gondwana pattern with episodic, jump dispersal events is the biogeographic historical representation that best fits the Anthothoe species tree. The high population differentiation possibly amplified by the occurrence of asexual reproduction makes it difficult to identify genes responsible for local adaptation, however, these seem to be mainly associated with cellular and metabolic processes. We propose a new set of species hypotheses for the Southern Hemispheric Anthothoe clade, based on the pronounced genomic divergence observed among lineages. Although the link between the genetic and phenotypic differentiation remains elusive, newer sequencing technologies are bringing us closer to understanding the evolution of sea anemone diversity and, therefore, how to appropriately classify them.
KW - Actiniaria
KW - Anthothoe
KW - Local adaptation
KW - RAD sequencing
KW - Southern Gondwana pattern
KW - Species delimitation
UR - http://www.scopus.com/inward/record.url?scp=85048568432&partnerID=8YFLogxK
U2 - 10.1016/j.ympev.2018.05.022
DO - 10.1016/j.ympev.2018.05.022
M3 - Article
C2 - 29800649
AN - SCOPUS:85048568432
SN - 1055-7903
VL - 127
SP - 217
EP - 228
JO - Molecular Phylogenetics and Evolution
JF - Molecular Phylogenetics and Evolution
ER -