Physical Evidence for Macroevolution

Evolution is evidenced by (a)   and studies of organisms and their (b)   . Fossils of animals with living (c)   have shown that animals continue to experience changes such as size, beak shape, talon shape, and other things over time.

• fossils
• DNA
• descendants

There are (a)   structures which are bones or organs that appear in different animals, but with a similar purpose, which leads scientists to believe they have a common (b)   . The arm of a (c)   and the wing of a (d)   have similar bone structures which suggests a common ancestor long ago.

• homologous
• ancestor
• human
• bird

What are homologous structures?

• Homologous structures are anatomical features in different species that share a common ancestry.
• Similar structures in unrelated species due to convergent evolution.
• Anatomical features that arise from environmental adaptations.
• Structures that are identical in function but not in structure.

What are anatomical features?

• Anatomical features refer to the diets of organisms.
• Anatomical features are the habitats where organisms live.
• Anatomical features are the behaviors of organisms.
• Anatomical features are the physical structures and characteristics of organisms.

​ (a)   structures are similar structures in organisms, but without a common ancestor. For example, the wings in a bat and a bird have very different bones which suggests they ​ (b)   evolved.

• Analogous
• independently

(a)   structures: same bones in a new function = a (b)   . (c)   structures: different bones in same function = likely (d)   .

• Homologous
• common ancestor
• Analogous
• independent evolution

Scientists believe that genetic change occurs at roughly the same pace. Therefore, the fewer genetic differences between a species, the closer they are thought to be related.

• True
• False