BSC 2011C Lecture Notes - Lecture 1: Heredity
Document Summary
50% of e biodiversity: life on e: 3 observations. Things have metabolism, no heredity -> not alive (eg: hurricane) Things have heredity, no metabolism -> not alive (eg: crystals) Virus: have heredity (dna, rna), no metabolism -> not alive in strict sense. All living creatures must be built from set of instructions passed on from generation to generation. Instructions exist as genetic code in digital format that can be copied, encoded in complex molecule in nucleus: dna. All life has dna: where life came from. Supernatural explanation: creationism: life created by somebody. Scientific explanation: all species descended form a common ancestor via natural process -> evolutionary (darwin: ideas about change over time. Fossils: found in strata: layers of sedimentary rock. Cuvier noted: the older the stratum -> fossils r less similar 2 current living species -> extinction -> boundaries btw strata = catastrophic events. Geologists: changes in e surface result from slow continuous process, still happening.
