Inbreeding Accumulation

Project accumulated inbreeding using an explicit initial coefficient and constant effective size.

Description

Inbreeding can accumulate as a finite population loses heterozygosity across generations.

Inbreeding can accumulate as a finite population loses heterozygosity across generations. A constant effective population size supplies a fixed per-generation increment.

Project accumulated inbreeding using an explicit initial coefficient and constant effective size.

When to use Inbreeding Accumulation

Use this for the following task: Project accumulated inbreeding using an explicit initial coefficient and constant effective size.

Prepare the observed records or explicit model parameters requested below. Keep probabilities as fractions and paired records aligned.

How to use Inbreeding Accumulation and understand its results

Prepare the observed records or explicit model parameters requested below. Keep probabilities as fractions and paired records aligned.
Enter initialInbreeding, effectiveSize, generations using the field table, then run the tool.
Read deltaFPerGeneration, finalInbreeding. 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
initialInbreeding	Initial inbreeding	number	Required
effectiveSize	Effective size	number	Required
generations	Generations	integer	Required

Require initial F in [0,1], effective size at least 0.5 and nonnegative integer generations. Apply the recurrence in closed form.^[1]

ΔF=1/(2Ne); finalF=1−(1−initialF)(1−ΔF)^generations

This summarizes the declared operation. Units, indexing, inclusivity and exceptional cases are explained in the surrounding text.

Output field	Meaning	Value type
deltaFPerGeneration	Delta f per generation	number
finalInbreeding	Final inbreeding	number

json

{
  "input": {
    "initialInbreeding": 0.1,
    "effectiveSize": 5,
    "generations": 2
  },
  "output": {
    "deltaFPerGeneration": 0.1,
    "finalInbreeding": 0.2709999999999999
  }
}

Limitations and assumptions

Effective size is not necessarily census size. Migration, selection and size changes are excluded.

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 Bottleneck Heterozygosity Loss for this operation: Project heterozygosity loss over a constant-size diploid bottleneck. For a complementary task, use Independent Inbreeding Paths for this operation: Sum caller-validated independent common-ancestor path contributions to offspring inbreeding.

The implementation reference documents the exact calculation, supported input shapes and returned fields.

References

Inbreeding Accumulation — tool.io

Similar or alternative tools

Bottleneck Heterozygosity Loss
Project heterozygosity loss over a constant-size diploid bottleneck.
Independent Inbreeding Paths
Sum caller-validated independent common-ancestor path contributions to offspring inbreeding.