What structure on the human body is comparable to the alula?

The alula is a small structure that is found on birds. It is located at the joint between the hand wing and the arm wings of birds and it is the freely moving, first digit of a bird's wing. It is normally used by birds in slow flight. In humans, the structure that is comparable to the alula is the thumb.

If the experiment was perfomed more then once and you get the same results

Ithink the dna sequences may vary but the amino acid sequences are identical.