BIO152H5 Lecture Notes - Lecture 9: Goose Bumps
Document Summary
Earth is old: geologic data puts earth at ~4. 6 billion years old fossil data shows first signs of life at ~3. 4-3. 8 billion years old earth"s topography, environment, and inhabitants have changed over time planet and its species are dynamic. Fossils: traces of organisms that lived in the past (shells, tracks, bones, dung, eggs, etc) soft tissue does not preserve well, gaps in fossil record. Fossils provide evidence for extinct species not all fossils resemble living organisms extinction is evidence that species are dynamic transitional forms living species succeed fossil species. Vestigial traits can be reduced, partially reduced, some function, no function example is the human tailbone at the end of the spine, goose bumps.
