the.com/atavism
when evolution's greatest hits album plays a track you thought was deleted.
means the reappearance of an ancestral trait after generations of absence, biological or behavioral.
from from latin atavus, meaning great-great-great-grandfather — coined by darwin-era naturalists trying to explain why traits sometimes skip forward instead of fading out.
whalesoccasionally born with tiny vestigial leg bones
humansrare cases of babies born with small tails
psychology usedescribes regressive, primitive behavior under stress