Conserving adaptive potential: lessons from Tasmanian devils and their transmissible cancer

Area of Science:

• Conservation genetics
• Evolutionary biology
• Wildlife management

Background:

• Adaptive genetic variation is key for species survival, especially against threats like disease.
• Genomic tools now enable identification of specific genes linked to fitness in endangered species.
• Tasmanian devils (Sarcophilus harrisii) are critically threatened by a transmissible cancer, devil facial tumor disease (DFTD).

Purpose of the Study:

• To investigate how wild Tasmanian devil populations are genetically adapting to DFTD.
• To inform conservation and management strategies for both wild and captive devil populations.
• To evaluate the effectiveness of current conservation approaches in light of new genetic insights.

Main Methods:

• Genomic analysis to identify loci associated with DFTD resistance.
• Population modeling to predict devil persistence under various scenarios.
• Review of existing conservation practices, including captive breeding and translocations.

Main Results:

• Wild devil populations exhibit genetic variation for DFTD resistance, including immune response and tumor regression.
• Rapid evolution in response to DFTD has been observed in natural populations.
• Models predict devil persistence at lower densities, challenging earlier extinction predictions.
• Current management focusing on genome-wide diversity or demographic supplementation may be detrimental.

Conclusions:

• Translocating captive devils may cause outbreeding depression and increase DFTD spread, outweighing demographic benefits.
• Monitoring genetic variation at DFTD-associated loci is essential for both captive and wild populations.
• Future conservation strategies should consider targeted genetic management to preserve adaptive variation for DFTD resistance.