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๐ŸŒณ Family Genetics Tool

Family Trait Tree

Enter traits for both sets of grandparents and both parents to build a 3-generation trait inheritance map. See how genetic traits flow through your family and estimate what your child inherits.

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Trait Type
Maternal Grandparents
Paternal Grandparents
Parents
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Family Trait Tree โ€“ 3-Generation Inheritance Visualiser | TraitGen

Generated at traitgen.com, Free genetics education. Not medical advice.

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โš ๏ธ Educational only. Probability estimates based on genetic models, not medical advice.

๐Ÿ’ก Did you know?

Family trait trees (pedigrees) are the oldest tool in genetics, predating DNA discovery by over 80 years. Medical geneticists still use pedigree charts today to trace hereditary disease risk across generations.

The Science

The science of genetic pedigrees

Pedigree charts track phenotypes through generations to infer underlying genotypes. For single-gene Mendelian traits, looking at grandparents allows us to confidently predict whether a parent is a carrier (heterozygous) for a recessive trait, which greatly narrows down the child's probability distribution.

What is a genetic pedigree?

A diagram showing lineage and inheritance of a trait. It is used by geneticists to analyze inheritance patterns and estimate genotypes.

How traits travel down generations

Genes travel in chromosomes, with alleles sorting independently, passing from grandparent to parent to child.

Recessive traits in family trees

Recessive traits show up in family trees as skipped generations, only appearing when two carrier lineages join.

Why siblings in the same family differ

Even with identical family trees, the recombination of parental DNA in each child is unique, meaning different siblings express different paths.

FAQ

Frequently Asked Questions

How far back do inherited traits go?

Theoretically, indefinitely, but practically, the genetic contribution of ancestors halves each generation. You share only 12.5% DNA with a great-grandparent, meaning their direct physical influence is small.

Can traits come from great-grandparents?

Yes, especially recessive traits like red hair or blue eyes, which can hide as carrier genes for multiple generations before expressing.

Why does our family have different eye colors?

Because the parents carry multiple different pigment alleles inherited from their own parents (grandparents), allowing different combinations to form.

How do geneticists read pedigree charts?

Standard charts use squares for males, circles for females, and shaded shapes for individuals expressing the trait, mapping relations across rows.