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After visiting the Falkland Islands during the voyage of the Beagle, Charles Darwin remarked on the surprising presence of a wolf-like canid unique to the islands [1 • Darwin C. The zoology of the voyage of H.M.S. Beagle, under the command of Captain Fitzroy, R.N., during the years 1832 to 1836. Smith, Elder and Co, London, London1838 • Google Scholar ]. One hundred and forty years after its extinction [2 • Clutton-Brock J. • Corbet G.G. • Hills M. A review of the family Canidae, with a classification by numerical methods.Bull. Brit. Mus. Nat. Hist. 1976; 29: 119-199 • Google Scholar ], the evolutionary relationships of this unusual canid remain unresolved. Here, we present a phylogenetic analysis based on nuclear and mtDNA sequence data from the extinct Falklands wolf and find that its closest extant relative is the South American maned wolf. Molecular dating analyses suggest that the Falklands wolf and several extant South American canid lineages likely evolved in North America, prior to the Great American Interchange. The Falklands wolf was the sole representative of a distinct South American canid lineage that survived the end-Pleistocene extinctions on an island refuge.
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Magazine
R937
study is now required to address
several open questions. Most
pertinently: how do ants encode
skyline information? And, how do
ants derive a movement direction
from the comparison of their current
skyline view and their remembered
view? Recent experiments, also with
M. bagoti [10], have addressed the
first question. By masking different
portions of the visual panorama, it
was possible to show that being able
to view prominent skyline features
at high retinal elevations was
neither necessary nor sufficient for
successful orientation. This suggests
that M. bagoti derive information
from a broad range of azimuthal
directions rather than a small set of
the most prominent features.
Supplemental Data
Supplemental data are available at
http://www.cell.com/current-biology/
supplemental/S0960-9822(09)01585-1
Acknowledgments
This work was supported by the Australian
Research Council, the Leverhulme Trust
and the BBSRC.
References
1. Wehner, R., Michel, B., and Antonsen, P.
(1996). Visual navigation in insects: coupling
of egocentric and geocentric information.
J. Exp. Biol. 199, 129–140.
2. Collett, T.S., Graham, P., and Durier, V.
(2003). Route learning by insects. Curr. Opin.
Neurobiol. 13, 718–725.
3. Collett, T.S., Graham, P., Harris, R.A., and
Hempel-De-Ibarra, N. (2006). Navigational
memories in ants and bees: memory retrieval
when selecting and following routes. Adv.
Stud. Behav. 36, 123–171.
4. Fukushi, T. (2001). Homing in wood ants,
Formica japonica: use of the skyline
panorama. J. Exp. Biol. 204, 2063–2072.
5. Collett, T.S., Graham, P., and Harris, R.A.
(2007). Novel landmark-guided routes in ants.
J. Exp. Biol. 210, 20–25.
6. Towne, W.F., and Moscrip, H. (2008). The
connection between landscapes and the
solar ephemeris in honeybees. J. Exp. Biol.
211, 3729–3736.
7. Collett, M., Collett, T.S., Bisch, S., and
Wehner, R. (1998). Local and global vectors
in desert ant navigation. Nature 394,
269–272.
8. ller, R. (2002). Insects could exploit
UV-green contrast for landmark navigation.
J. Theor. Biol. 214, 619–632.
9. Stürzl, W., and Zeil, J. (2007). Depth, contrast
and view-based homing in outdoor scenes.
Biol. Cyber. 96, 519–531.
10. Graham, P., and Cheng, K. (2009) Which
portion of the natural panorama is used
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desert ant? J. Comp. Physiol. A. 195,
681–689.
1School of Life Sciences, University of
Sussex, Brighton, UK. 2Department of
Brain, Behaviour and Evolution, Macquarie
University, Sydney, Australia.
*E-mail: p.r.graham@sussex.ac.uk
We sequenced the complete
cytochrome oxidase II mitochondrial
gene and part of the cytochrome b
gene from five museum specimens
of Falklands wolf, including one
specimen collected by Darwin
himself (see Supplemental data
published with this article online
for details). We also sequenced
four nuclear loci containing
phylogenetically informative
polymorphisms. Phylogenetic
analyses of these datasets using
neighbour joining, maximum
likelihood and Bayesian inference
do not recover a close relationship
between the Falklands wolf and
South American foxes (Cerdocyon
and Pseudalopex) or Canis species,
as suggested by morphological
data [2,5,6]. In contrast, we found
a surprising and well-supported
sister group relationship to the South
American maned wolf (Chrysocyon
brachyurus) (Figure 1). Given our
limited sequence data, we were
unable to recover a monophyletic
South American canid clade, or a
clade comprising the maned wolf and
bush dog (Speothos venaticus) in our
unconstrained analyses. However,
a topology constrained to include
these well-documented relationships
is not significantly less likely than
the tree produced by unconstrained
analyses (see Supplemental data).
Furthermore, the monophyly of both
the South American canids and
the maned wolf/Falklands wolf/
bush dog clade are independently
supported by nuclear polymorphisms
(Figure 1). Although the maned wolf
is the closest extant relative of the
Falklands wolf, a morphologically
similar species, Dusicyon avus,
survived in South America until the
mid-Holocene [7]. This species may
have an even closer relationship
with the Falklands wolf and warrants
further investigation.
Both Darwin [1] and Fitzroy [3]
were surprised by the striking
differences between the Falklands
wolf and the canids of the South
American mainland. We estimated
the divergence time between the
Falklands wolf and maned wolf as 6.7
million years ago (mya) (Figure 1;
95% highest probability density
(HPD) = 4.2–8.9 mya). Such a long
divergence time, coupled with
subsequent ecological isolation on
the Falkland Islands may account
for the pronounced morphological
Evolutionary history
of the Falklands
wolf
Graham J. Slater1,*,†, Olaf Thalmann1,†,
Jennifer A. Leonard2,
Rena M. Schweizer1,
Klaus-Peter Koepfli1,
John P. Pollinger1,
Nicolas J. Rawlence3,
Jeremy J. Austin3, Alan Cooper3,
and Robert K. Wayne1
After visiting the Falkland Islands
during the voyage of the Beagle,
Charles Darwin remarked on the
surprising presence of a wolf-like canid
unique to the islands [1]. One hundred
and forty years after its extinction [2],
the evolutionary relationships of this
unusual canid remain unresolved.
Here, we present a phylogenetic
analysis based on nuclear and mtDNA
sequence data from the extinct
Falklands wolf and find that its closest
extant relative is the South American
maned wolf. Molecular dating analyses
suggest that the Falklands wolf
and several extant South American
canid lineages likely evolved in North
America, prior to the Great American
Interchange. The Falklands wolf was
the sole representative of a distinct
South American canid lineage
that survived the end-Pleistocene
extinctions on an island refuge.
The Falklands wolf (Dusicyon
australis) was the only endemic
terrestrial mammal inhabiting the
Falkland Islands until its extinction
in 1876 [1,2]. Since its description by
Darwin, the occurrence of this large,
wolf-like canid on a pair of islands 480
km from the eastern coast of Argentina
has remained a mystery [1–4]. Although
formerly abundant on the islands [1,4],
few museum specimens of the species
have been preserved. The Falklands
wolf presents a puzzling combination
of craniodental characteristics,
resulting in controversial taxonomic
alliances with domestic dogs (Canis
familiaris) [2], the North American
coyote (Canis latrans) [5], and South
American foxes (Pseudalopex and
Cerdocyon) [5,6]. Hypotheses for its
presence on the islands, which have
never been connected to the South
American mainland [7], have ranged
from dispersal by ice or logs [3,7],
to domestication and subsequent
transport by Native Americans [2].
Current Biology Vol 19 No 20
R938
divergence between these taxa.
Furthermore, based on our dating
analyses and fossil evidence, we
suggest that most South American
canid lineages originated in North
America [7,8]. At least six exclusively
South American canid lineages,
including the Falklands wolf,
originated prior to the formation
of a Panamanian land bridge
approximately 3 mya (Figure 1).
Canids are not recorded in the
South American fossil record until
the late Pliocene (Uquian, 2.5–1.5
mya [7]), while three South American
canid lineages are recorded in the
North American fossil record before
this time (Cerdocyon, 6–5 mya;
Chrysocyon, 5–4 mya; Theriodictis,
5–4 mya; [9]). The South American
canids probably evolved from the
fossil taxon Eucyon, which was
widespread in North America during
the late Miocene [9]. The ultimate
extinction of South American canid
lineages in North America may have
resulted from resource competition
with Canis, which immigrated to
the New World during the late
Pliocene [7,9].
Based on mtDNA sequence
analysis, we estimated the age of
the most recent common ancestor
of our Falklands wolf samples to
be 330 thousand years ago (kya)
(Figure 1; 95% HPD = 70–640 kya).
Genetic and archaeological evidence
suggests that humans first arrived in
the New World no earlier than 20–15
kya [10], implying that a human-
mediated origin of the Falklands
wolf is unlikely [3,9]. The Falklands
wolf may have reached the islands
by rafting or dispersing over glacial
ice [3,9] during the late Pleistocene
and was probably able to survive
into the recent past by subsisting on
a rich diet of penguins, geese and
pinnipeds [1,4]. Unfortunately, by the
time Darwin described the species,
its exploitation for the fur trade was
well underway. Forty years later, the
Falklands wolf was extinct, ending
a long evolutionary process of the
kind central to the development of
Darwin’s theories.
Supplemental Data
Supplemental data are available at
http://www.cell.com/current-biology/
supplemental/S0960-9822(09)01695-9.
Acknowledgments
We thank Ted Daeschler and Ned Gilmore
(ANSP), Paula Jenkins and Daphne Hills
(BMNH), Cody Fraser (Otago Museum,
NZ), Lars Werdelin (Swedish Museum of
Natural History), and Tony Parker and
Clem Fisher (World Museum Liverpool)
for access to specimens. Shauna Price
provided comments on previous versions
of the manuscript. Support was provided
by National Science Foundation support to
G.J.S. (DDIG 0709792) and R.K.W. (OPP-
0352604 and DEB-0614585/0614098) and
the Australian Research Council (20101413)
to N.J.R., J.J.A. and A.C.
References
1. Darwin, C. (1838). The zoology of the voyage
of H. M. S. Beagle, under the command
of Captain Fitzroy, R. N., during the years
1832 to 1836 (London: Smith, Elder and Co,
London).
2. Clutton-Brock, J., Corbet, G.G., and Hills, M.
(1976). A review of the family Canidae, with
a classification by numerical methods. Bull.
Brit. Mus. Nat. Hist. 29, 119–199.
3. FitzRoy, R. (1839). Narrative of the surveying
voyages of His Majesty’s Ships Adventure
and Beagle between the years 1826 and
1836, describing their examination of the
southern shores of South America, and the
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Proceedings of the second expedition, 1831-
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(1995). Phylogeny of the Caninae (Carnivora:
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3146, 1–37.
7. Berta, A. (1987). Origin, diversification,
and zoogeography of the South American
Canidae. Fieldiana: Zoology, 39, 455–471.
8. Wayne, R. K., Geffen, E., Girman, D. J.,
Koepfli, K.-P. Lau, L.M. and Marshall, C.R.
(1997). Molecular systematics of the Canidae.
Sys. Biol. 46, 622–653.
9. Wang, X., Tedford, R.H. and Anton, M. (2008).
Dogs: Their Fossil Relatives and Evolutionary
History (New York: Columbia University
Press).
10. Jobling, M. A., Hurles, M.E., and Tyler-Smith
C. (2004). Human Evolutionary Genetics:
Origins, Peoples and Disease (New York:
Garland Science).
1Department of Ecology and Evolutionary
Biology, University of California, Los
Angeles, 621 Charles E. Young Drive
South, Los Angeles, CA 90095-1606, USA.
2Estación Biológica de Doñana-CSIC,
41092 Sevilla, Spain and Department of
Evolutionary Biology, Uppsala University,
75236 Uppsala, Sweden. 3Australian Centre
for Ancient DNA, University of Adelaide,
South Australia 5005, Australia. These
authors contributed equally to this work.
*E-mail: gslater@ucla.edu
Red fox
Bush dog
Maned wolf
Falklands wolf
Hoary fox
Crab-eating fox
Sechuran fox
Pampas fox
Small-eared dog
Falklands wolf
Falklands wolf
Falklands wolf
0.02.55.07.510.012.515.017.5
0.98/78/-
0.97/74/73
1.00/100/100
1.00/99/100
0.99/83/100
Millions of years before present
Culpeo fox
0.86/-/96
Red fox
Bush dog
Maned wolf
Hoary fox
Crab-eating fox
Small-eared dog
CH21
VTN
G
G
G
G
G
G
A
A
A
C
C
C
C
C
C
T
T
T
G...C
A...T
A...T
A...T
A...T
G...C
A...T
A...T
A...T
Pseudalopex foxes
Canis spp.
Canis species
VANGL2
Falklands wolf
Current Biology
Figure 1. Chronogram showing phylogenetic relationships of the Falklands wolf.
Colour bars indicate phylogenetically informative polymorphisms shared by the Falklands wolf.
The Falklands wolf also lacks an insertion (purple arrowhead) specific to the South American foxes.
The shaded green bar indicates formation of the Panamanian isthmus. Node support values are
Bayesian inference/maximum likelihood/neighbour-joining. Values < 70% are indicated by a hy-
phen. Canid images with permission from D.W. MacDonald and P. Barrett (1999). Mammals of
Europe (London: Harper Collins); J.F. Eisenberg and K.H. Redford (1999). Mammals of the Neotrop-
ics, Volume 3 The Central Neotropics: Ecuador, Peru, Bolivia, Brazil (Chicago: Chicago University
Press); and St. G. Mivart (1890). A Monograph of the Canidae: Dogs, Jackals, Wolves, and Foxes
(London: Porter).
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Vol. 3 was reissued the same year in separate form. v. 1. Proceedings of the first expedition, 1826-1830, under the command of Captain P. Parker King -- v. 2. Proceedings of the second expedition, 1831-1836, under the command of Captain Robert Fitz-Roy -- Appendix to vol. 2 -- v. 3. Journal and remarks, 1832-1836 / by Charles Darwin.