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

Area of Science:

• Evolutionary Biology
• Paleoclimatology
• Conservation Genetics

Background:

• Species' responses to habitat expansion are understood, but responses to habitat contraction are less clear.
• The hypothesis of habitat tracking suggests species can adapt to both increasing and decreasing habitat availability.
• An alternative hypothesis posits that populations outside refugia face extinction during climate shifts.

Purpose of the Study:

• To investigate how species respond to habitat contraction using the arctic fox (Alopex lagopus) as a model.
• To test the habitat tracking hypothesis against the extinction hypothesis during climate change events.

Main Methods:

• Utilized ancient DNA techniques to analyze genetic variation in arctic fox populations.
• Examined genetic data across a habitat expansion and contraction cycle spanning the Pleistocene-Holocene transition.

Main Results:

• Arctic foxes in midlatitude Europe became extinct at the end of the Pleistocene epoch.
• These populations did not track their habitat as it shifted northward.
• High genetic similarity between Scandinavian and Siberian populations indicates an eastern origin for Scandinavian arctic foxes post-glaciation.

Conclusions:

• Species, particularly arctic ones, may be unable to track habitat decreases during climate change.
• Arctic species are likely vulnerable to rising global temperatures due to potential habitat loss.
• The findings challenge the universal applicability of the habitat tracking hypothesis for all species during climate shifts.