Answer:
Those parts have become vestigial
Explanation:
Organisms have few parts that are not useful to them because those parts in them have become vestigial.
When an organism has a part is no more using, it relates to the evolutionary history of such organism.
- These parts are called vestigial body parts.
- They are not needed for the survival of an organism again and they can do without them.
- At a certain point in time, those parts might be very vital to the sustenance of such organism.
- With time, those parts becomes useless and redundant.
