Expected life - Kitai Jyumyō

…The life span of an individual, which is affected by the living environment and conditions, is called the ecological life span, and the life span of an individual, which continues from reaching a natural life span until death due to physiological causes such as old age, is called the physiological life span (maximum life span, limiting life span). The average life span used in demography refers to the average remaining life expectancy of a newborn (the expected life span that indicates how many more years an individual who has survived to a certain age can live on average). In addition to the life span of an individual, the life span of a species, the life span of a population, and the life span of the cells and molecules that make up an organism are also known. …

*Some of the terminology that refers to "expected life" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…このように，生活環境や条件によって影響を受ける個々の個体の生存期間を生態的寿命とよび，天寿を全うして老衰などの生理的原因によって死亡するまで続く個体の生存期間を生理的寿命(最大寿命，限界寿命)とよぶ。人口学的に用いられる平均寿命とは，新生児の平均余命(ある年齢まで生存した個体が平均あとなん年生存できるかを示す期待寿命)をさす。生物には個体の寿命のほかに，種の寿命，集団の寿命，生物体を構成する細胞や分子の寿命が知られている。…

※「期待寿命」について言及している用語解説の一部を掲載しています。

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