Evolution Biological evolution ? Def. ?descent with modification? -small scale evolution ? changes in gene frequency in a population from one generation to the next -Large scale evolution ? descent of different species from a common ancestor over many generations Natural Selection -organisms exist that have variable traits (populations have variation) ? ex: flower color -those traits will determine how successful that organism is in nature (how many offspring it will produce) -If these traits are heritable, they will be carried on to the next generation. ? ex: brightly colored flowers pollinated more often, produce more seeds (offspring) -Populations change over time reflecting these successes ? over time, population shifts to become brightly colored Bacteria ? our system E coli ? benefits: easy to grow in a lab, grow fast Sampling ourselves Human Microbiome Project ? this is characterizing all the diff. bacteria that grow on or in humans Selectively Recover E. Coli Taking a swab from ourselves ? swab butt Plate on Eosin-Methylene Blue Agar ? this plate is selective?the dye inhibits gram positive organisms (we want gram negative ones that ferment lactose.) Should be green. Swab for Week 1 (and streak out) Transfer to plates containing antibiotics ? week 2
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