Question

what is the term for a functionless anatomical structure often reduced in size a that is evidence of an organism's evolutionary past?

Answer 1

I believe that would be the Vestigial Structure.

Answer 2

Vestigial structure

Step-by-step explanation:

• The vestigial structures are the remnants of the evolutionary past of the organism which continues to persist in the modern forms however, they are either atrophied, rudimentary or degenerate.
• These structures have either lost their functionality in the modern organisms or if they retain any function it is mostly different from the original function and much reduced.
• An example of the vestigial structure is plica semilunaris which is a small fold present in the inner corner of the eye and it is a remnant of the nictating membrane in the early organisms.