Entry: atavistically (adj.)
In context: "Besides Hal, who's atavistically dark-complected anyway..."
Definition: From atavism (n.): Resemblance to grand-parents or more remote ancestors rather than to parents; tendency to reproduce the ancestral type in animals or plants.
Also, if you take disease or symptom broadly:
b. Pathol. Recurrence of the disease or constitutional symptoms of an ancestor after the intermission of one or more generations.
Other: A word familiar from Hunter S. Thompson.
Very cool usages:
1915 W. S. Maugham Of Human Bondage xxvi. 108 Some atavistic inheritance of the cave-dweller.
1922 J. Joyce Ulysses iii. 645 The sporadic reappearance of atavistic delinquency.
SNOOT score: 3
Source: Oxford English Dictionary