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Macroevolution Broad pattern of evolution Above the species level

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Presentation on theme: "Macroevolution Broad pattern of evolution Above the species level"— Presentation transcript:

1 Macroevolution Broad pattern of evolution Above the species level
Ex. movement of species onto land Impact of mass extinctions on diversity of life Key adaptations (i.e. wings in birds)

2 Fossil Record Helps us document the history of life (reflects macroevolution) Shows us that great change has happened over time Many species from the past do not look like those today Documents how new species have arisen from past ones Incomplete record!!!

3 How Rocks and Fossils are Dated
Relative dating -Using rock layers to determine age of fossil Strata- sediment layers

4 2. Absolute Dating Common method is radiometric dating
Based on decay of radioactive isotopes Radioactive decay Rate of decay expressed by the half-life Time required for 50% of parent isotope to decay Each isotope has a unique half-life Fossils contain isotopes they acquired during their lifetime Carbon 12, radioactive isotope carbon 14- this decays after death into nitrogen 14

5 Geologic Record Standard time scale DO NOT NEED TO KNOW ORDER!!!
See pg. 439

6 Plate Tectonics and Continental Drift
Impacts on diversity of life Alters habitats Climate change Allopatric speciation on large scale

7 Mass Extinctions Fossil record show that almost all species that have lived are extinct Mass extinction- when many species go extinct worldwide 5 mass extinctions 6th one happening now?

8 Adaptive Radiation Period of evolutionary change in which groups of organisms form many new species that have adaptations that allow them to fill new ecological roles Has happened after each 5 mass extinctions

9 Changes in Developmental Genes
Help us to understand the biological processes that cause the changes we see in the fossil record What are master regulatory genes called that control body pattern? Evolutionary biologists believe that changes in the forms of organisms may be caused by mutations in regulatory switches

10 Is Evolution Goal-Oriented?
NO!!!!!


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