C.16.3 and 16.4

Chapter 16.3


Define Vocabulary



Natural Selection


Natural selection occurs in any situation in which more individuals are born than can survive.

According to the Principles of common descent, all species, living and extinct, are descended from ancient common ancestors.


See Figure 16-9 on page 461

See Figure 16-10 on page 462

See Figure 16-11 on page 463


Chapter 16.4

 Define Vocabulary


Homologous structure

Analogous structure

Vestigial structure


Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors.

Many recently discovered fossils forms trace the evolution of modern species from their extinct ancestor.

 Theory explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.


See Figure 16-13 on page 466-467

See Figure  16-14 on page 468

See Figure 16-17 on page 472


Complete 16.3- 16.4 Worksheet

We will go over the answers together in class