BIS 2C Lecture Notes - Lecture 6: Prokaryote, Paraphyly, Eukaryote
10 Aug 2018
School
Department
Course
Document Summary
1/17/18 lecture 6 - the tree of life & microbes. Past attempts at the tree of life. Before tree thinking: aristotle"s great chain of being, 1500s. Each species designed for a particular purpose, thought to be unchanging. Darwin, origin of species 1859 set the stage for tree thinking. Ernst haeckel, 1866: tree based on morphology. Five kingdoms 1969: based on morphology, physiology, ecology. Cause: landscape change, pesticide, parasites & pathogens. Microsporidia characteristics: intracellular parasite, infect arthropods/vertebrates, no mitochondria, have nucleus, makes spores allow for dormancy outside host. Now know there are many eukaryotes that lack mitochondria or have highly reduced one. Do not meet requirements for phylogenetically informative traits. All life has same characteristics (dna, 3 letter code) Trees now based on dna sequencing of whole organisms. Carl woese & the 3 domains of life. Sequencing rrna: 3 domains, 1987 - eubacteria, archaebacteria, eukaryotes. Carl woese looked at molecular machinery of cells to build tree based on data.
