This document provides evidence for evolution from 5 areas of scientific study: the fossil record, comparative anatomy, comparative embryology, molecular biology, and biogeography. Each area is summarized briefly: the fossil record shows transitional forms; comparative anatomy examines homologous, analogous, and vestigial structures; comparative embryology shows similarities in development of related species; molecular biology compares DNA/protein sequences; and biogeography looks at species distribution and examples of divergent and convergent evolution.

1. Catalyst: If the answer is False, explain why.
1. True or false. Populations tend to be stable
in size.
2. True or false. All individuals in a species
are exactly alike.
3. True or false. Different traits can be
inherited.
4. True or false. Resources are unlimited.
5. True or false. Natural selection is when
organisms with superior traits survive to
pass those traits onto offspring.

2. Evidence for Evolution

3. 5 areas of scientific study provide evidence for
evolution.
1.) Fossil Record
2.) Comparative Anatomy
3.) Comparative Embryology
4.) Molecular Biology
5.) Biogeography

4. Fossil Record
• The progression of
forms observed in
the fossil record is
consistent with
other inferences
about the major
branches of
descent in the tree
of life.

6. • The Darwinian view of
life
– Predicts that
evolutionary transitions
should leave signs in
the fossil record
• Paleontologists
– Have discovered
fossils of many such
transitional forms
Fossil Record

7. Comparative Anatomy
The study of anatomical structures and
evolutionary relationships.
• Homologous structures
• Analogous structures
• Vestigial structures

8. Comparative Anatomy
• Homologous structures: are anatomical
resemblances between organisms that represent
variations on a structural theme that was present in
a common ancestor
Figure 22.14
Human Cat Whale Bat

9. Comparative Anatomy
• Analogous structures: superficial similarities
that reflect an adaptation reflective of similar
environments, not a descent from a common
ancestor

10. • Vestigial structures: remnants of
structures that served important functions in
the organism’s ancestors

11. Comparative Embryology
• Closely related organisms go through similar
stages in their embryonic development.
• All vertebrate embryos go through a stage in
which thy have gill pouches and tails.

12. Molecular Biology
• Scientists examine the nucleotide of DNA
and amino acid sequences of proteins from
different species. Closely related species
share higher percentages of sequences
than species that are distantly related.

13. Molecular Biology
• More than 98% of DNA sequences are
identical in humans and chimpanzees.

14. Biogeography
• The use of geography to describe the
distribution of species.

15. Biogeography: Divergent Evolution
• After the supercontinent Pangaea separated,
similar species diverged due to different
environments.

16. Biogeography: Convergent Evolution
• Unrelated species from different regions
around the world converge or begin to look
alike when found in similar environments.

17. Divergent Convergent Parallel
Evolution Evolution Evolution

18. Connection: Biogeography and Comparative
Anatomy
• Types of comparative anatomy can also be
classified as convergent and divergent
evolution, which structure is an example of
divergent evolution? Convergent evolution?