1	Macroevolution Evidence A section addressing fossils as evidence for macroevolution.
2	From our Prior Discussion Evidence for Macroevolution Anatomy Vestigial Structures Embryology Biochemistry
3	Types of Evidence for Macroevolution History in Rocks! Fossils are clues to the past A fossil is evidence of an organism that lived long ago. Scientists who study ancient life are called Paleontologists They use fossils to learn more about the organisms from the past Example: What could fossils of teeth reveal to us?
4	Evidence for Macroevolution In addition to revealing information about past organisms, fossils may additionally reveal information about: Climate Geography By studying the position, condition, and location of fossils and rocks, scientists can learn about our ancient environment and geography
5	Evidence for Macroevolution Fossil Formation In order to form, organisms must be buried in mud, sand, or clay Over time, they become compressed and harden into a sedimentary rock. Fossils are not usually formed in other rock types due to the way other rocks form (extreme heat, pressure, chemicals, etc.) Let’s look into some common types of fossils!
6	Evidence for Macroevolution Types of fossils: Trace fossils Any indirect evidence left by an animal Examples: ? Casts Minerals in rocks that fill a space left by a decayed organism
7	Evidence for Macroevolution Types of fossils, continued: Molds Organism is buried, decays, thus leaving an empty space outlining the organism Petrified Minerals penetrate and replace the hard parts of an organism Amber or frozen Occurs when an entire organism becomes trapped in ice or tree sap that hardened into amber
8	Evidence for Macroevolution How can we determine the age of fossils? 1. Relative dating or “order of appearance”: The determination of an age based by the layer of rock it is found within Magazine example 2. Radiometric dating The utilization of a radioactive isotope Radioactive isotopes are atoms that when broken down give off radiation and forms a new isotope in the process. These isotopes can be measured thus revealing the approximate age of the rock.
9	Speciation Definition: the evolution of new species A possible cause: Geographic isolation When a physical barrier divides the population