Ch. 14 (word) - LTCC Online

Earth History and Macroevolution. ... To date fossils older than 50,000 yr old, paleontologists use other isotopes with longer half lifes. For example, Potassium 40 is an isotope with a half life of 1.3 billion years. ... Under debate. 1. classical - tends to depend on subjective evaluation. cladistics - tends to depend on objective evaluation ... ................
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