Absolute Dating
Relative Dating
Using fossils
presence in strata to
recreate the earth’s
history (geological
time scale) and thus
an overview of
species evolution
•Radioactive isotopes
half-life
Examples:
Carbon-14 (5600)
Potassium-40 (1.25 bil)
Uranium-238 (4.5bil)
Ex. A fossil is estimated
to contain ¼ of the original
amount of C-14. About
how old is the fossil?
11,200
•Racemization
ratio of L/D amino acids
1
2
Sources Cited
• Campbell, 5th edition
• http://bio.kimunity.com/ap_biology
http://www.mie.utoronto.ca/labs/lcdlab/biopic/fig/23.12.jpg
3