変異

• Reading: へんい
• Romaji: hen'i
• Kanji breakdown: 変 (hen) — change, unusual; 異 (i) — different, strange, anomalous
• Pronunciation: /hen.i/

Meaning

Variation; mutation; anomaly. In biology, a heritable change in genetic material; more broadly, any deviation from the normal or expected form.

In genetics and evolutionary biology, 変異 refers to mutations at the DNA level as well as phenotypic variation within populations. Distinguished from 突然変異 (sudden point mutation), 変異 can encompass broader patterns of natural variation. Also used in linguistics (language variation), virology (pathogen variant strains), and medicine. A key concept in Darwinian natural selection.

Examples

1. ウイルスの変異によって、既存のワクチンが効果を失うことがある。 Viral mutations can cause existing vaccines to lose their effectiveness.
2. この地域の植物は気候変動に応じた変異を数世代かけて示してきた。 Plants in this region have shown variation adapted to climate change over several generations.
3. 遺伝子変異が特定の疾患リスクを高めることが最新研究で明らかになった。 Recent research has revealed that certain genetic mutations increase the risk of specific diseases.

Usage Guide

Context: genetics, biology, virology, medicine

Tone: scientific

Origin & History

Compound of 変 (change) + 異 (different, unusual). Used in scientific Japanese since the Meiji period as a translation for biological variation and mutation concepts from Western biology.

Cultural Context

Era: Meiji–Modern

Generation: Adults

Social background: Academic/Medical