Pedigrees

What is a Pedigree:

A pedigree is like a family tree, but instead of showing relationships, it illustrates the inheritance of traits over generations. This tool helps geneticists and scientists trace the occurrence of specific traits or genetic conditions within families.

Representation:

• Squares: Represent males.

• Circles: Represent females.

• Shaded Symbols: Indicate individuals expressing a particular trait or condition.

• Lines: Connect parents and offspring.

Parental and Filial Generations:

• Parental Generation (P): This is the first generation you start with. It consists of the parents you're initially observing.

Filial Generation (F): These are the subsequent generations of offspring.

Reading a Pedigree:

• Shapes and Lines:

  • Squares for males, circles for females.

  • Lines connecting them show parent-offspring relationships.

• Shading:

  • Shaded symbols indicate individuals expressing a particular trait or condition.

• Generations:

  • Rows represent different generations. The top row is the first generation (P), the next row is the first filial generation (F1), and so on.

• Siblings:

  • Siblings are shown as a vertical line beneath the parents, connected by horizontal lines.

• Marriages:

  • A horizontal line connecting a male and a female indicates a marriage.

• Generational Changes:

  • As you move down rows, you're progressing through generations.