Calculate Inbreeding Coefficient Of Pedigree

Inbreeding Coefficient Formula:

\[ F = \sum \left( \frac{1}{2} \right)^{n1 + n2 + 1} \times (1 + F_A) \]

Generations to Common Ancestor (n1):

generations

Generations to Common Ancestor (n2):

generations

Inbreeding of Ancestor (F_A):

coefficient

Inbreeding Coefficient (F):

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1. What Is The Inbreeding Coefficient?

The inbreeding coefficient (F) measures the probability that two alleles at any locus in an individual are identical by descent from a common ancestor. It quantifies the genetic similarity within a pedigree structure.

2. How Does The Calculator Work?

The calculator uses the standard inbreeding coefficient formula:

\[ F = \sum \left( \frac{1}{2} \right)^{n1 + n2 + 1} \times (1 + F_A) \]

Where:

\( n1 \) — Number of generations from individual to common ancestor through first parent
\( n2 \) — Number of generations from individual to common ancestor through second parent
\( F_A \) — Inbreeding coefficient of the common ancestor

Explanation: The formula calculates the probability that two alleles from a common ancestor are inherited by both parents and result in homozygous offspring.

3. Importance Of Inbreeding Coefficient

Details: The inbreeding coefficient is crucial in population genetics, animal breeding, and conservation biology. It helps assess genetic diversity, predict inbreeding depression, and manage breeding programs to maintain healthy populations.

4. Using The Calculator

Tips: Enter the number of generations to the common ancestor through each parent (n1 and n2) and the inbreeding coefficient of the common ancestor (F_A). All values must be valid positive numbers with F_A between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What does an inbreeding coefficient of 0 mean?
A: An inbreeding coefficient of 0 indicates no inbreeding - the parents are completely unrelated and share no common ancestors in the pedigree.

Q2: What is considered a high inbreeding coefficient?
A: Values above 0.0625 (equivalent to first cousins) are generally considered significant. Values above 0.25 (parent-offspring or sibling mating) represent extreme inbreeding.

Q3: How is this different from relatedness coefficient?
A: The inbreeding coefficient (F) measures homozygosity due to related parents, while the relatedness coefficient (r) measures the proportion of shared genes between two individuals.

Q4: Can the coefficient be negative?
A: No, inbreeding coefficients range from 0 to 1. Negative values are not biologically meaningful in standard pedigree analysis.

Q5: How accurate is this calculation for complex pedigrees?
A: For complex pedigrees with multiple common ancestors, the calculation should be summed over all paths. This calculator handles a single common ancestor path.