Diversity and connections from a genetic and genomic perspective.
Investigating genetic variation among individuals and populations can support conservation questions. Study design should reflect the spatial scale, organisms and hypotheses under investigation.
The question comes before the marker.
The study can investigate how genetic diversity is distributed among sampled individuals and whether differences exist between sampling locations or sets of samples.
Questions about connectivity must distinguish organism movement from gene flow. Genetic interpretation does not automatically equate to direct observation of current movements across the landscape.
Diversity, structure and conservation.
- Genetic diversity: characterize the variation observed in the samples and markers analyzed.
- Population structure: assess patterns of genetic differentiation among the sampled groups.
- Connectivity: investigate hypotheses of genetic exchange, considering the scale and analytical assumptions.
- Conservation: integrate genetic evidence with ecological information and population history.
Individuals and sampling locations are part of the analysis.
The number of individuals, distribution of sampling locations, collection period and choice of markers depend on the question. There is no universal sample size that ensures all inferences.
Microsatellites, SNPs and sequencing are options to assess according to the question and study design.
Poorly representative samples can limit comparisons. Material availability and preservation, as well as sampling history, need to be discussed before defining the scope.
- Specify which populations or sampling locations will be compared.
- Define hypotheses and spatial and temporal scales.
- Assess markers and analyses appropriate to the information needed.
Evidence to guide management questions.
Studies can support discussions of differentiation among populations, conservation of genetic diversity and possible effects of isolation. The applicability of each analysis must be assessed on a case-by-case basis.
Management decisions require integrating these results with the ecological context and other available evidence. Genetics contributes to the assessment; it does not determine the decision on its own.
Genetics in the context of conservation ↗The scale of inference must be explicit.
Results reflect the samples, markers and models used. Patterns of differentiation do not, by themselves, identify a single cause or automatically demonstrate a current barrier to movement.
The absence of detectable differentiation does not prove unrestricted connectivity either. Interpretation depends on data resolution and the assumptions of each analysis.
Which question about populations guides your study?
Tell us about the project context, environment and the question you need to answer. An initial conversation helps define the approach and scope.