noun
Technical term in biology and anthropology for mating or reproduction between individuals of different genetic lines, populations, or social groups.
異系交配は遺伝的多様性を高める。
Outbreeding increases genetic diversity.
その部族では異系交配が伝統的に行われている。
Exogamy is traditionally practiced in that tribe.
Compound of 異系 (different lineage) and 交配 (mating/crossing). The exact historical derivation is uncertain, but the term is a modern technical coinage.