Inferring recent historic abundance from current genetic diversity

Area of Science:

• Population Genetics
• Conservation Biology
• Evolutionary Biology

Background:

• Estimating recent historic abundance is crucial for endangered species conservation and understanding past ecological states.
• Population genetic theory is increasingly used to infer historic population sizes from contemporary genetic diversity.
• These genetic-based estimates often result in unexpectedly large historic abundance figures.

Purpose of the Study:

• To review and critically evaluate the theory and common practices for estimating recent historic abundance from genetic diversity.
• To identify potential issues and limitations in current estimation methodologies.
• To explore novel approaches for more accurate inference of historic population sizes.

Main Methods:

• Review of existing literature on population genetic theory applied to historic abundance estimation.
• Critical evaluation of common practices and potential biases in genetic diversity-based assessments.
• Discussion of spatio-temporal scale mismatches between estimation methods and conservation objectives.

Main Results:

• Genetic diversity-based estimates often represent long-term averages, potentially mismatching the goal of assessing recent abundance for specific populations.
• A key challenge is the discrepancy in spatio-temporal scales between the genetic data and the desired estimate.
• Current promising approaches require genetic samples with similar spatial and temporal characteristics.

Conclusions:

• Estimating recent historic abundance from contemporary genetic diversity faces challenges, particularly regarding temporal and spatial scales.
• Future research should focus on methods that better align estimation scales with conservation needs.
• Genome-enabled inference methods utilizing dense marker data, like identity-by-descent tracts, offer potential for inferring historic abundance from contemporary samples alone.