Regular Article
Phylogenetic Relationships within the Eared Seals (Otariidae: Carnivora): Implications for the Historical Biogeography of the Family

https://doi.org/10.1006/mpev.2001.1012Get rights and content

Abstract

Phylogenetic relationships within the family Otariidae were investigated using two regions of the mitochondrial genome. A 360-bp region of the cytochrome b gene was employed for the primary phylogenetic analysis, while a 356-bp segment of the control region was used to enhance resolution of the terminal nodes. Traditional classification of the family into the subfamilies Arctocephalinae (fur seals) and Otariinae (sea lions) is not supported, with the fur seal Callorhinus ursinus having a basal relationship relative to the rest of the family. This is consistent with the fossil record which suggests that this genus diverged from the line leading to the remaining fur seals and sea lions about 6 million years ago (mya). There is also little evidence to support or refute the monophyly of sea lions. Four sea lion clades and five fur seal clades were observed, but relationships among these clades are unclear. Similar genetic divergences between the sea lion clades (Da = 0.054–0.078), as well as between the major Arctocephalus fur seal clades (Da = 0.040–0.069) suggest that these groups underwent periods of rapid radiation at about the time they diverged from each other. Rapid radiations of this type make the resolution of relationships between the resulting species difficult and indicate the requirement for additional molecular data from both nuclear and mitochondrial genes. The phylogenetic relationships within the family and the genetic distances among some taxa highlight inconsistencies in the current taxonomic classification of the family.

References (62)

  • P.B. Vrana et al.

    Higher level relationships of the Arctoid Carnivora based on sequence data and ‘total evidence’

    Mol. Phylog. Evol.

    (1994)
  • U. Arnason et al.

    A molecular view of pinniped relationships with particular emphasis on the true seals

    J. Mol. Evol.

    (1995)
  • U. Arnason et al.

    The complete mitochondrial sequence of the harbor seal, Phoca vitulina

    J. Mol. Evol.

    (1992)
  • L.G. Barnes et al.

    Status of studies on fossil marine mammals

    Mar. Mamm. Sci.

    (1985)
  • A. Berta et al.

    Callorhinus gilmorei n. sp., (Carnivora: Otariidae) from the San Diego formation (Blancan) and its implications for otariid phylogeny

    Trans. San Diego Soc. Nat. Hist.

    (1986)
  • O.R.P. Bininda-Emonds et al.

    Building large trees by combining phylogenetic information: A complete phylogeny of the extant Carnivora (Mammalia)

    Biol. Rev. Camb. Philos. Soc.

    (1999)
  • Brunner, S. 2000, Cranial morphometrics of fur seals and sea lions (family: Otariidae)—systematics, geographic...
  • M.P. Cummings et al.

    Sampling properties of DNA sequence data in phylogenetic analysis

    Mol. Biol. Evol.

    (1995)
  • Felsenstein, J. 1993, PHYLIP (Phylogeny Inference Package) version 3.5c. Distributed by the author, Department of...
  • S.D. Goldsworthy et al.

    Mate choice among sympatric fur seals: Female preference for conphenotypic males

    Behav. Ecol. Sociobiol.

    (1999)
  • S.D. Goldsworthy et al.

    Variation in the mitochondrial control region in the Juan Fernandez fur seal (Arctocephalus philippii)

    J. Hered.

    (2000)
  • S.D. Goldsworthy et al.

    Field identification of Australian and New Zealand fur seals, Arctocephalus spp., based on external features

  • A. Graybeal

    Is it better to add taxa or characters to a difficult phylogenetic problem?

    Syst. Biol.

    (1998)
  • H.C. Harpending et al.

    Genetic traces of ancient demography

    Proc. Natl. Acad. Sci. USA

    (1998)
  • D.M. Hillis et al.

    Signal, noise and reliability in molecular phylogenetic analyses

    J. Hered.

    (1992)
  • M. Kallersjo et al.

    Homoplay increases phylogenetic structure

    Cladistics

    (1999)
  • K.C. Kim et al.

    Specific antiquity of the sucking lice and evolution of otariid seals

    Rapp. P-V. Reun. Con. Internat. Explor. Mer

    (1975)
  • M. Kimura

    A simple method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences

    J. Mol. Evol.

    (1980)
  • J.E. King

    Sea lions of the genera Neophoca and Phocarctos

    Mammalia

    (1960)
  • J.E. King

    The identity of the fur seals of Australia

    Aust. J. Zool.

    (1969)
  • J.E. King

    On the specific name of the southern sea lion (Pinnipedia, Otariidae)

    J. Mammal.

    (1978)
  • J.E. King

    Seals of the World

    (1983)
  • T.D. Kocher et al.

    Dynamics of mitochondrial DNA evolution in animals: Amplification and sequencing with conserved primers

    Proc. Natl. Acad. Sci. USA

    (1989)
  • Kumar, S, Tamura, K, and, Nei, M. 1993, MEGA: Molecular Evolutionary Genetics Analysis, version 1.0, pp, The...
  • G.M. Lento

    Molecular Systematics and Population Genetic Studies of Pinnipeds: Phylogenies of our Fin-Footed Friends and their Surreptitious “Species” Status

    School of Biological Sciences

    (1995)
  • G.M. Lento et al.

    Genetic variation of southern hemisphere fur seals (Arctocephalus spp.): Investigation of population structure and species identity

    J. Hered.

    (1997)
  • G.M. Lento et al.

    Use of spectral analysis to test hypotheses on the origin of pinnipeds

    Mol. Biol. Ecol.

    (1995)
  • G.M. Lento et al.

    Geographic distribution of mitochondrial cytochrome b DNA haplotypes in New Zealand fur seals (Arctocephalus forsteri)

    Can. J. Zool.

    (1994)
  • J.E. Maldonado et al.

    Intraspecific genetic differentiation in California sea lions (Zalophus californianus) from southern California and the Gulf of California

    Mar. Mamm. Sci.

    (1995)
  • R. Masuda et al.

    A molecular phylogeny of the family Mustelidae (Mammalia, Carnivora), based on comparison of mitochondrial cytochrome b nucleotide sequences

    Zool. Sci.

    (1994)

    • Cited by (0)

    1

    To whom correspondence should be addressed. Forensic Science Service Tasmania, 20 St. Johns Ave., Newtown Tas. 7008, Australia. Fax: +61 3 62785693. E-mail: [email protected].

    View full text
    Copyright © 2001 Academic Press. All rights reserved.