BIO152H5 Lecture Notes - Lecture 10: Arrector Pili Muscle, Hemoglobin, Hominidae
Document Summary
Lecture 10 evolution: central concept of biology. Evidence for change through time: extinctions, fossils, biogeographical, developmental, and genetic/molecular evidence. Geologic data show that earth is ~ 4. 6 byo. Fossil data show the earliest signs of life in rocks is ~ 3. 4-3. 8 byo. Earth"s topography, environment, and living organisms have changed drastically over time: pangaea all continents used to be connected but now, plate tectonics have shifted. Darwin described evolution as descent with modification: change over time produced modern species from ancestral species. The theory of evolution by natural selection makes two claims about the nature of species: species are related by common ancestry, species change through time. Many fossils provide evidence for extinct species. Fossils: traces of living organisms that lived in the past: ex. bird tracks dated 50 mya, sloth dung that"s 20 kya etc, often teeth, bone, shells, claws; anything that is hard because soft parts get decomposed very quickly.
