Biodiversity of LifeEvolution and Diversification of Eukaryotes:- Eukaryotes evolved from prokaryotesReview of life for 1.75 billion years ago:- Single celled- No cellular compartmentalization- Metabolically diverse, but limited feed abilities - No nucleus (no regulation of gene expression)o Have to have transcription can’t without nucleusGreat Moments of Evolution:- Domain Eukarya evolution advances of cells:o True nucleuso Organelles Mitochondria Chloroplasts (some)o More complex cytoskeleton Usually 10x’s larger Keeps organelle in place, but they are still able to be mobileAncestors of Eukaryotes:- Single-celled bacteria or archaea (or both)o Might have fused together?- Lost cell wall- Gained ingestion via phagocytosiso Digest, absorbs nutrients, spits back out- Developed nucleus- Acquired mitochondria- 99% of things that have lived on this planet have gone extinctFormation of Nucleus:- One hypothesis: in folding of plasma membrane (seen in bacteria)- Made nucleus and endoplasmic reticulum (location of some ribosomes)- Separates transcription and translation, regulation of gene expressionMitochondria Acquired via Endosymbiosis:Steps:1. One bacteria ingests a proteobacteria2. Form symbiosis3. Pass endosymbiosis to offspring4. Transfer genes- To have endosymbiosis must have phagocytosis1. Start with two independent bacteria2. One bacterium engulfs the other3. One bacteria now lives inside the other4. Both bacteria benefit from the arrangement5. The internal bacteria are passed on from generation to generationChloroplasts acquired by engulfing a cyanobacteria- BUT, happened more than once in evolutionary history!- Was eukaryotic because it already had mitochondria- Primary=1st time- Secondary Symbiosis= eukaryote eats another eukaryote that has already ate a cyanobacteriaIs this possible??- Green sea slug!o It ate another organism (ingested algae) retain chloroplast, but can’t pass them on- Proteobacteria lives endosymbiotically with an aphid (permanent gene transfer)Evidence for Endosymbiosis- Size of organelles similar to prokaryotes- Have two membranes- Have own DNA-circular- Divided by binary fission- Have own ribosomes and make own proteins- DNA of mitochondria most closely related to proteobacteriaWhat is a “Protist”?- A Eukaryote that is NOT a plant, animal, or funguso Examples: Amoeba, slime molds, euglena, diatoms, algae- Paraphyletic, not monophyletic o Contains organisms that are NOT ProtistaProtist Characteristics:- Mainly unicellular, some multicellular (no tissues)- Photoautotrophs (photosynthesis) or heterotrophs- Most live in or near water- Some sexual reproduction, some asexualProtists-ecology and importance- Low species richness, but high abundance- Important photosynthesizers, source of oil- Pinoflagellants… red tides- TOXINS!- Diseases: Malaria, amoebic, dysentery, glardia- Irish potato