BIOL 1001 Lecture Notes - Lecture 3: Geologic Time Scale, Stoma, Aniridia
14 Jan 2017
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Document Summary
Darwin describes evolution as descent w/modifications- descendant species are modified. 2 statements about nature of species: species change through time, species are related by common ancestry. Fossil is traces of an organism that lived in the past- bones, branches tracks or impressions. Fossil record consists of all fossils that have been found & described in scientific literature. Geologic time scale: a sequence of named intervals called eons, eras & periods that represented the (cid:373)ajor eve(cid:374)ts i(cid:374) earth"s history. Sedimentary rocks form from sand, mud & other materials deposited at locations such as beaches or rivers. Sedimentary rocks, volcanic ash, lava form in layers- with younger layers deposited on top of older layers. Earlies signs of life appear in rocks that formed 3. 4-3. 8 billion years ago. Darwin interpreted extinct forms of life as evidence that species is(cid:374)"t static. States that the array of species on earth had changed through time.
