Coefficient of relationship

Japanese: 血縁係数 - けつえんけいすう（英語表記）coefficient of relationship

It is a coefficient that indicates the strength of the blood relationship between two individuals who share a common ancestor, and was introduced by S. Wright (1922). The blood relationship coefficient between individuals I and J is the correlation coefficient between genotype values when it is assumed that the action of genes is additive (dominance relationship, no interaction), and is given by the following formula: Here, F _I and F _J are the inbreeding coefficients of I and J, respectively, and F _IJ is the blood relationship coefficient between I and J. The blood relationship coefficient is also a coefficient that indicates how similar individuals are genetically, and indicates the probability that when one gene is taken from I and one gene is taken from J at a certain locus, they are derived from a common ancestral gene, and is calculated by the following formula.

Source: Heibonsha World Encyclopedia, 2nd Edition Information

Japanese:

共通の祖先をもつ2個体の間の血縁関係の強さを示す係数で，ライトS.Wrightにより導入されたもの(1922)。個体Iと個体Jの間の血縁係数は，遺伝子の作用が相加的(優性関係，相互作用がない)であると仮定したときの遺伝子型値間の相関係数であり，次式で与えられる。ここにF_I,F_JはそれぞれI,Jの近交係数であり，F_IJはIとJの間の近縁係数である。近縁係数coefficient of parentageも個体が遺伝的にどれほど似ているかを示す係数で，ある遺伝子座でIから1個，Jから1個の遺伝子を取り出したとき，それらが共通の祖先遺伝子から由来する確率を示すもので，次式で計算される。

出典　株式会社平凡社世界大百科事典第２版について　情報

<<: Kin selection

>>: Blood ties - kinship