Evidence of evolution
Evolution: “descent with modification”
◦ Different species are related, not independent creations.
◦ Species change thru time.
Determine age of Earth and different strata: radiometric dating
Radioactive decay: loss of atomic particles from nucleus at a regular rate that is
Radioactive decay discovered about 1900
Took over 60 years to work out details of U-238 decay
Uranium-238: 4.5 billion years
-- volcanic rock
Potassium-40: 1.3 billion years
Carbon-14: 5,700 years
-- date organisms that died within last 50,000
Hard parts mineralized in sedimentary rock.
Pressure turns sediments into rock:
◦ Sand à Sandstone
◦ Clay à Shale
◦ Shell à Limestone
• Use radiometr