BIOL 211 Lecture Notes - Lecture 1: Burgess Shale, Cyanobacteria, Paleozoic
Document Summary
Anaerobic prokaryotes: bacteria and archaea, lasted for nearly 2 billion years. Endosymbiosis- leads to the creation of eukaryotes at about 2. 7 billion years inside that become eukaryotes. Stromatolites- cyanobacteria mats that float on the top of water. Endosymbiosis is when prokaryotes engulf other prokaryotes and create organelles: bacteria, archaea, eucarya. The common ancestor of these was likely just a community of cells that continuously traded genes. 640 million years ago- the beginning of multicellular life (ex. Cambrian (explosion) period-first subset period within the paleozoic era. The burgess shale- a good place to find preserved fossils in british columbia. Formation of the early jawless vertebrate (haikouichthys) Rate of extinction: averages about 20% extinction of diversity every million years. Greater than 60% loss of species in one million years. The species do not die off in groups such as land or water rather the entire earth is usually affected. There were 5 major mass extinctions: (listed in chronological order)
