TY - JOUR

T1 - Fin whale (Balaenoptera physalus) mitogenomics

T2 - A cautionary tale of defining sub-species from mitochondrial sequence monophyly

AU - Cabrera, Andrea A.

AU - Hoekendijk, Jeroen P.A.

AU - Aguilar, Alex

AU - Barco, Susan G.

AU - Berrow, Simon

AU - Bloch, Dorete

AU - Borrell, Asunción

AU - Cunha, Haydée A.

AU - Dalla Rosa, Luciano

AU - Dias, Carolina P.

AU - Gauffier, Pauline

AU - Hao, Wensi

AU - Landry, Scott

AU - Larsen, Finn

AU - Martín, Vidal

AU - Mizroch, Sally

AU - Oosting, Tom

AU - Øien, Nils

AU - Pampoulie, Christophe

AU - Panigada, Simone

AU - Prieto, Rui

AU - Ramp, Christian

AU - Rivera-Léon, Vania

AU - Robbins, Jooke

AU - Ryan, Conor

AU - Schall, Elena

AU - Sears, Richard

AU - Silva, Mónica A.

AU - Urbán, Jorge

AU - Wenzel, Frederick W.

AU - Palsbøll, Per J.

AU - Bérubé, Martine

PY - 2019

Y1 - 2019

N2 - The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 380 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively “trivial” aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic.

AB - The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 380 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively “trivial” aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic.

KW - Balaenoptera physalus

KW - Fin whale

KW - Mitochondrial genome

KW - North Atlantic Ocean

KW - Subspecies

U2 - 10.1016/j.ympev.2019.02.003

DO - 10.1016/j.ympev.2019.02.003

M3 - Journal article

C2 - 30771513

AN - SCOPUS:85062634102

VL - 135

SP - 86

EP - 97

JO - Molecular Phylogenetics and Evolution

JF - Molecular Phylogenetics and Evolution

SN - 1055-7903

ER -