ISB 202 Lecture Notes - Lecture 3: Cambrian Explosion, Organic Matter, Prokaryote

• School: MSU
• Department: Integrative Studies Biological
• Course: ISB 202
• Professor: P.Rasmussen

Document Summary

The first cells may have originated by chemical evolution on a young earth: Somehow gaining the ability to self replicate: 4. Prokaryotes dominant from 3. 5-2. 0 bya: earliest organisms almost certainly prokaryotes, prokaryote: simple, single celled organisms without organelles, early on, pro. We can observe the same processes now that happened on early earth: bacteria from ancient warm water vents. Eukaryotic life bega by 2. 1 billion years ago: eukaryotic cells, all other life forms than prokaryotes, mostly larger, more complex. Incorporated prokaryotes into their cells: evolved into cell structures, 1st eukaryote known from slightly after oxygen revolution (2. 1 bya) Cambrian explosion: 2nd radiation of eukaryotes produced most major animal groups in early cambrian, 520 mya , corals and sponges existed earlier, when most animals first evolved hard parts. Processes affecting number and types of species on earth = biodiversity: biodiversity (species richness) = speciation minus extinction, speciation, appearance and spread, extinction, disappearance.