名詞 atavism:

1. a reappearance of an earlier characteristic
   同義詞：reversion, throwback

at.a.vism

n.（名詞）
The reappearance of a characteristic in an organism after several generations of absence, usually caused by the chance recombination of genes.
返祖現(xiàn)象，隔代遺傳：機(jī)體特征在幾代缺失后重新出現(xiàn)，通常由基因重組引起
An individual or a part that exhibits atavism.Also called throwback
返祖體：表現(xiàn)出返祖現(xiàn)象的個(gè)體或部分也作 throwback
The return of a trait or recurrence of previous behavior after a period of absence.
重現(xiàn)：經(jīng)過一段時(shí)間的缺失后，一特征的重新出現(xiàn)或以前特性的再次發(fā)生

來源：
French atavisme
法語 atavisme
from Latin atavus [ancestor]
源自 拉丁語 atavus [祖先]
atta [father]
atta [父親]
avus [grandfather] * see awo-
avus [祖父] *參見 awo-

【引伸】
at.avist
n.（名詞）
at.avis.tic
adj.（形容詞）
at.avis.tically
adv.（副詞）