1. Sudden appearance?
Most organisms in the fossil record do not contain transitional forms.
Instead, there is a sudden appearance of a new form or organism that had not previously been seen in the fossils
Cambrian Explosion

2. Punctuated Equilibrium
This idea states that evolution occurs mainly in sudden bursts, with long periods of little change. This idea may be an explanation for the lack of intermediate forms in the fossil record. How did this happen? Punctuated equilibrium doesn’t explain how it happened, and the answer to that question is still debated.

3. Punctuated Equilibrium
Gradualism

4. Biogeography
Biogeography is the study of the distribution of plants and animals throughout the world Each of the continents has its own distinctive fauna and flora

5. Biogeography
Jaguars
Leopards

6. Anatomical Homologies
Homologous structures - Similar structures but different functions Indicates common ancestry

7. Anatomical Homologies
Analogous structures – structures with a superficially similar form or function, but different anatomy Believed to have evolved separately

8. Vestigial Structures
Structures in an organism that serve no apparent function Indicates a common ancestor Example: Appendix in humans (but has some immune system benefits) Whale Pelvis Bones (but has some use during male reproduction) suggests ancestor had legs

9. Vestigial Structures Example: Snake with legs
Example: Flightless birds with wings
These spurs on male snakes help with reproduction

10. Vestigial Structures
Example: Humans have a tail bone; suggests ancestors had tails
Example: Vampire bat has molar teeth; suggests ancestor chewed food
Example: Blind cavefish has eye sockets but no eyes; suggests ancestor had eyes