1. morphologists: interested in structures and function evolutionary biologists: support for evolutionary theory systematists: interested in phylogenetic relationships of extant and extinct animals paleontologists: interested in structures for identification of extinct animals Who studies paleontology?

2. HOMOLOGY vs. ANALOGY Homology: share a recent common ancestor Homologies are established by: fossil record, historical biogeography embryology, comparative anatomy (e.g., topographic location) genetics (DNA, molecular sequence data) Homologous structures do not have to look alike (e.g., bird beaks, feet, or feathers) but they do share a recent common ancestor. Analogy: shared function, but no recent common ancestor Analogous structures often appear similar (superficially) because of their function e.g., penguin wing / dolphin fin shark fin / ichthyosaur fin

3. Slide of the rock cycle and importance of sedimentary rocks to the rock record and fossilization. The Rock Cycle

4. Fossils are found in Sedimentary Rocks. The rocks can be: detrital: physical break down of pre-existing rocks chemical: produced by chemical precipitating dissolved minerals out of solution. The minerals are in solution from chemical weathering of preexisting rocks. Transportation and deposition processes: ice (glaciers), water (rivers, streams, oceans), and air (loess). Transportation is related to the amount of energy in the system.

5. Depositional Environments Continental environments: e.g., fluvial, desert, glacial Transitional environments: e.g., beach, delta, barrier islands. Marine environments: e.g., continental shelf, carbonate platform, continental slope and rise, deep-ocean basin, evaporite environments. Paleoenvironmental interpretations are based upon the evidence found in the rocks, e.g., organisms, niche, habitat, water depth, etc. Different environmental settings form little or no deposits, while other deposits become soils. Lithification is the process of compaction and/or cementation.

6. Sandstone Sand is a particle size and sandstone is a composite. Most sandstone is made up of quartzand a few other minerals. For minerals to become sedimentary rock they must be available, mechanically durable, and chemically stable. Typical sedimentary rock facies include: sand facies, mud facies, and carbonate (limestone) facies. Marine transgressions and regressions are major worldwide events that are recorded in the rock record. They are used to hypothesize correlations of eustatic sea levels (rise and fall).

7. Examples of sedimentary structures are: strata or beds, graded beds, paleo-currents, and mud cracks.

8. Fossils are found in an altered condition, e.g., permineralized and an unaltered condition, e.g., mummification. Types of fossils can be body or trace fossils or coprolites. Fossilization as a process includes: petrified, permineralization, and carbonized. Requirements for permineralization include: rapid burial, mineral rich water percolating through the sediments, and time. Erosion exposes fossils to a trained observer.

10. Geologic Time Relative versus Absolute time Fundamental principles of relative time are the principle of uniformitarianism, superposition, lateral continuity, cross-cutting relationships, inclusion, and fossil succession. Principles of relative dating and the geologic maps explain ideas like correlation and include key beds and guide fossils. Geologic maps also include information, e.g., unconformity (disconformity, angular unconformity, and nonconformity) and what is a hiatus (missing data).

11. Relative versus Absolute Time

12. Fossil Succession

13. Lateral Continuity

14. Singular History of Life on Earth

15. Origin of Life 3800 Million Years Before Present

16. Submarine Hydrothermal Vent

17. Age of Stromatolites 2500 Million Years Before Present

18. Prokaryotic and Eukaryotic Cells

19. Major Episodes in the History of Life