BIO120H1 Lecture Notes - Lecture 2: Speciation, Natural Selection, Transitional Fossil

• School: UTSG
• Department: Biology
• Course: BIO120H1
• Professor: Spencer C H Barrett

Document Summary

To biologists, fossils are valuable and without them, we would not have a clear outline of evolution. Advances in physics, geology and biochemistry have provided insight into the past. Estimating the age of the rock need half life, how much radioisotope there was when the rock formed, how much remains now. Uranium is used to date old rocks. Carbon is used to date younger rocks such as wood, bone, human artifacts. Half life does not change when under extreme temperatures and pressures. The big evolutionary picture a scan through the entire sequence of rock strata should show early life to be simple with more complex species appearing only after some time. Later species should have traits that make them look like the descendants of earlier ones. Youngest fossils should be most similar to living species. Should be able to see splitting in the fossil record.