BIO152H5 Lecture Notes - Lecture 21: Symmetry In Biology, Phanerozoic, Ocean Acidification
Document Summary
The fossil record reveals changes in the kinds of organisms on earth over time. Few individuals have fossilized, and even fewer have been discovered. The fossil record is biased in favour of species that. Fossil discoveries can be a matter of chance or prediction. For example, paleontologists found tiktaalik, an early terrestrial vertebrate, by targeting sedimentary rock from a specific time and environment. The geologic record is divided into the archaean, the proterozoic, and the phanerozoic eons. The phanerozoic includes the last half billion years, and encompasses multicellular eukaryotic life. The phanerozoic is divided into three eras: the paleozoic, mesozoic, and cenozoic. Big bang 4600 mass extinction radiation. Serial endosymbiosis supposes that mitochondria evolved before plastids through a sequence of endosymbiotic events. Key evidence supporting the endosymbiotic origin of mitochondria and plastids includes: Inner membranes are similar to plasma membranes of prokaryotes. Division and dna structure are similar in these organelles and prokaryotes.
