The 20 individuals featured have distinctive genetic traits that are hard to forget

One thumb for each parent.

Although nobody is exactly the same as their parents, they do share certain similarities. He is the inheritor of an bizarre thing. He has inherited a thumb from each of his parents. The thumbs on his left and right appear different in shape and size, and resemble the thumbs of his parents which can be seen to the right and left of his own thumbs in the above picture.