Article

Ancient DNA reveals lack of postglacial habitat tracking in the arctic fox.

Centro UCM-ISCIII de Evolución y Comportamiento Humanos, C/ Sinesio Delgado 4, Pabellón 14, 28029 Madrid, Spain.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 05/2007; 104(16):6726-9. DOI: 10.1073/pnas.0701341104
Source: PubMed

ABSTRACT How species respond to an increased availability of habitat, for example at the end of the last glaciation, has been well established. In contrast, little is known about the opposite process, when the amount of habitat decreases. The hypothesis of habitat tracking predicts that species should be able to track both increases and decreases in habitat availability. The alternative hypothesis is that populations outside refugia become extinct during periods of unsuitable climate. To test these hypotheses, we used ancient DNA techniques to examine genetic variation in the arctic fox (Alopex lagopus) through an expansion/contraction cycle. The results show that the arctic fox in midlatitude Europe became extinct at the end of the Pleistocene and did not track the habitat when it shifted to the north. Instead, a high genetic similarity between the extant populations in Scandinavia and Siberia suggests an eastern origin for the Scandinavian population at the end of the last glaciation. These results provide new insights into how species respond to climate change, since they suggest that populations are unable to track decreases in habitat avaliability. This implies that arctic species may be particularly vulnerable to increases in global temperatures.

Download full-text

Full-text

Available from: Anders Angerbjörn, Jun 19, 2015
0 Followers
 · 
173 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Quantitative analysis of macroecological patterns for late Pleistocene assemblages can be useful for disentangling the causes of late Quaternary extinctions (LQE). However, previous analyses have usually assumed linear relationships between macroecological traits, such as body size and range size/range shift, that may have led to erroneous interpretations. Here, we analyzed mammalian datasets to show how macroecological patterns support climate change as an important driver of the LQE, which is contrary to previous analyses that did not account for more complex relationships among traits. We employed quantile regression methods that allow a detailed and fine-tuned quantitative analysis of complex macroecological patterns revealed as polygonal relationships (i.e., constraint envelopes). We showed that these triangular-shaped envelopes that describe the macroecological relationship between body size and geographical range shift reflect nonrandom extinction processes under which the large-bodied species are more prone to extinction during events of severe habitat loss, such as glacial/interglacial transitions. Hence, we provide both a theoretical background and methodological framework to better understand how climate change induces body size-biased species sorting and shapes complex macroecological patterns.
    Quaternary Research 07/2014; 82(1). DOI:10.1016/j.yqres.2014.02.003 · 2.58 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Small isolated populations often show lower genetic variability. Demographic bottlenecks lead to loss of genetic variation too. Arctic foxes (Vulpes lagopus) have been isolated since the Pleistocene on Mednyi and Bering Islands (Commander Islands). In 1970–1980, the Mednyi population passed through a severe bottleneck due to a mange outbreak. Previous studies showed lack of genetic diversity in the contemporary Mednyi population that could be due to the long history of isolation and/or the recent bottleneck. To test both factors, we analyzed the mtDNA D‐loop fragment and five microsatellites in pre‐bottleneck Mednyi museum samples. Also, contemporary Mednyi, Bering and mainland Alaskan Arctic foxes were analyzed. Registered genetic variability in historical Mednyi was higher than in contemporary Mednyi Arctic foxes, but lower than in contemporary the Bering population. Our data confirms that the bottleneck reduced an already depleted polymorphism in Mednyi Arctic foxes. Lack of genetic variability could be a reason why the Mednyi population did not recover following the outbreak of mange.
    Journal of Zoology 01/2013; 289(1). DOI:10.1111/j.1469-7998.2012.00964.x · 1.95 Impact Factor