Island Model Gene Flow
Estimate Nm from FST under the equilibrium diploid island model, not a direct migration measurement.
Description
The equilibrium diploid island model relates population differentiation to an effective migrants parameter.
The equilibrium diploid island model relates population differentiation to an effective migrants parameter. Its inversion depends on strong population-model assumptions.
Estimate Nm from FST under the equilibrium diploid island model, not a direct migration measurement.
When to use Island Model Gene Flow
Use this for the following task: Estimate Nm from FST under the equilibrium diploid island model, not a direct migration measurement.
Prepare the observed records or explicit model parameters requested below. Keep probabilities as fractions and paired records aligned.
How to use Island Model Gene Flow and understand its results
- Prepare the observed records or explicit model parameters requested below. Keep probabilities as fractions and paired records aligned.
- Enter fst using the field table, then run the tool.
- Read estimatedMigrantsPerGeneration. Interpret flags, units, ordering and placeholder values using the rules below.
- Review any reported issue or failed check, correct the supplied values when appropriate, and verify the result in its intended context.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| fst | Fst | number | Required |
Supply FST in (0,1]. Return the model estimate; FST=1 yields zero and FST=0 is rejected.1
Nm = (1/FST−1)/4 This summarizes the declared operation. Units, indexing, inclusivity and exceptional cases are explained in the surrounding text.
| Output field | Meaning | Value type |
|---|---|---|
| estimatedMigrantsPerGeneration | Estimated migrants per generation | number |
{
"input": {
"fst": 0.2
},
"output": {
"estimatedMigrantsPerGeneration": 1
}
}Limitations and assumptions
This is not a direct migration count. Equilibrium, symmetric migration and appropriate effective population assumptions are not tested.
The tool evaluates supplied observations or a declared model. It does not establish the biological cause of an observed pattern. Malformed requests produce input errors. A successfully evaluated request can still contain false flags, empty result lists or a result outside the supplied threshold; those outcomes have the meanings stated above.
Alternative or Complementary methods
Choose Population FST for this operation: Compute heterozygosity-based FST from population allele frequencies and explicit weights. For a complementary task, use Hardy Weinberg Assumption Audit for this operation: Audit caller-assessed Hardy–Weinberg assumptions without testing observed genotype equilibrium.
The implementation reference documents the exact calculation, supported input shapes and returned fields.
References
-
Island Model Gene Flow — tool.io
Similar or alternative tools
- Population FST
Compute heterozygosity-based FST from population allele frequencies and explicit weights.
- Hardy Weinberg Assumption Audit
Audit caller-assessed Hardy–Weinberg assumptions without testing observed genotype equilibrium.