Atavistic

Although the heterozygote gives it an atavistic appearance, the gene is not atavistic.

Thus the gene which produced atavistic digits in the vigorous heterozygous pentadactyl condition is a lethal monster in the homozygous condition.

Reactivation of a dormant atavistic gene could account for the abnormal costocoracoid ligament in humans.

They made me feel that I was alive in the nineteenth century, a sort of atavistic remnant, a romantic shred […]

The true perversion took place only in the privacy of her mind — the way she imagined an atavistic macho atop her when engaged in a mandatory contribution to the fetus-banks with some cretinous inept breeder…

Because I am atavistic enough to believe that drawing is the basic language of the illustrator, even as words comprise the basic language of the writer…