BIOEE 1780 1st Edition Lecture 7Outline of Last Lecture I. ReviewII. Molecular treesA) Neutral theory GeckosB) Coalescence III. MitochondriaOutline of Current lecture internal boneI. Summary of i-clicker review SnakesII. PhylogenyA) Phylogenetic terminology FishB) Tree-Thinking Part 3.5III. DiversityA) Similarities among all lifeB) Earliest signs of lifeC) VirusesD) LifeCurrent Lecture I. Summary of i-clicker review*A monophyletic group includes an ancestor and all of descendants*A paraphyletic groups include an ancestor, but not all of its descendants*An outgroup can help determine an ancestral state *A synapomorphy is a shared, derived trait between a group of organisms (can be a historical trait… the present species do not need to still have the trait [ex: a synampomorphy of geckos, anoles, and snakes is limbs, even though snakes no longer have them])*CAUTION: Synapomorphies must be traits that arose from the LATEST COMMON ANCESTOR … so if we include fish in the previous example of a phylogenetic tree, internal bone is a synapomorphy of snakes, lizards, and mammals because the trait arose before fish.II. PhylogenyA) Phylogenetic terminology*Homoplasy – traits due to convergent evolution*Convergent evolution – independent origin of similar traits (bats and birds developed wings, but not because a shared ancestor had wings)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.*Evolutionary reversal – return to an ancestral state (legs were evolved… then devolved to snakes)B) Tree-thinking part 3.5*Phylogeny can:- trace common traits and determine correlation-analyze epidemics (Ebola strains)-study coevolution-inform taxonomy-show the sequence of colonization of islandsIII. DiversityA) Similarities among all life*All organisms have RNA/DNA, and all have codons*Cellular unity*LUCA : Last Universal Common AncestorB) Earliest signs of life*Earth formed 4.6 billion years ago*Oldest evidence of life dates 3.7 billion years ago*Earliest eukaryote was 1.8 billion years ago*LUCA may not have been the first living organism… other lineages may have died off,and only LUCA survived to evolve to all living organismsC) Viruses*Not considered alive because there are no metabolic functions (no ATP, no ribosomes)*Evidence for multiple origins of virusesD) Life*About 2 million described species*Big Six model organisms: -E. Coli-Mouse-Fly---*We will learn about 130 taxa in this class*We will not learn Linnaean classification (except for domain, genus, and species)*Instead we use:LifeBacteria[Unnamed taxon]ArchaeaEukaryaAlveolatesStramenopilesExcavatesPlataeGlaucophytes[unnamed taxon]---AmoebozoansOpisthokontsFungi [Unnamed
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