1. EVIDENCE OF EVOLUTION
Chapter 15-2

2. Evolution defined
Change of heritable traits within a population through gradual modifications over generations (descent with modification)

3. Common Ancestor
All organisms share a common ancestor and have deviated from that ancestor over time

4. 1. Homologous Structures
Homologous Structures: body parts that are similar in structure may have different functions
Indicating at in the past they did the same job and came from a common ancestor

5. 2. Analogous Structures
Analogous Structures: same functions but different development
Indicates that different populations evolved to be better suited to the same environment

6. 3. Vestigial structures
Vestigial structures- remnants of organs or structures that had a function in an early ancestor
Shows that these organisms are descendants from organisms that used them
Ex: (tailbone coccyx or hip bones in whales)

9. 4. Fossils
Fossils provide geologic evidence of evolution since newer species are modified versions of older species
Fossil record contains the intermediates and transitional species that are now extinct

11. 5. Biogeography Geographical distribution of living things
The continents have not always been in the position they are now

12. Similar species are found in similar places showing common ancestry
Fossils of the same ancient species have been found on different continents providing evidence that they were once connected