Question

1. Have organisms changed over time?
2. How do we know?
3. What constitutes evidence of that change or lack of change?
(I just need help on 3 I just put 1 and 2 there for people to better understand the question.)

Answer 1

By looking at the remains of the organism and older remains of the Same or similar organism we can compare them to find the differences like bone structure or leaf shape

Answer 2

1 yes they have
2 we can tell by looking at fossil
3 This can be shown by looking back only a couple of hundred years ago and seeing we have not changed our human form