BIO 181 1st Edition Lecture 6Outline of Last Lecture I. Evidence of Evolution 2 II. MutationsOutline of Current Lecture I. Mechanism of EvolutionII. 2 factors of EvolutionIII. Genetic DrifCurrent LectureI. Mechanisms of Evolution: Microevolutiona. natural selection works on individualsi. single animal does not evolve, but population or species doesii. species members of population can breed fertile offspringb. Microevolutioni. genetic evolution: change in the gene pool from generation to generationii. natural selection: major cause of microevolutioniii. every organism has two allies for a given trait1. gene pool: entire genes in a population2. Mendel father of geneticsiv. genetic equilibrium: if no change occurs in gene frequency and population stays the samec. 2 factors that cause microevolution i. mutation/New gene arisesii. Evolutionary MechanismII. 2 factors of Evolutiona. mutation/New gene arisesi. mutation inherited are the reproductive onesii. changes the gene pool,iii. increase genetic variationiv. ASPM gene: contains repeat isoleucine and glutamine 75 letters, humans have 74 causing humans to have a bigger brainv. epigenetics: not mutation1. ex:men who smoke more likely to have sons who are obeseb. Evolutionary Mechanismi. alteration of existing variation, gene pool changing over timeii. most important part of this is natural selectionThese 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.iii. different reproduction of species causing them to be more vulnerable to predators1. ex: black moth in an area with light background being eating more quickly than gray moths, who can blend in easier to their environment, now see more gray moth2. natural selection can favor those reproducing earlier or faster3. major modes in natural selectiona. stabilizing:average trait selectedi. seen in bell curveii. very few outliersb. disruptive:extremes are selectedi. balanced polymorphismii. maintain both of the two non-average traits1. ex: those with sickle cell are less susceptible to malaria that allele stays around because it isuseful to a population2. bell shape curve3. flowers being picked were mostly medium size one, easier to pick due to human interference the medium average trait died out and only big and small ones leftc. directional: only one extreme favoredi. start with bell curveii. cheetahs that were fast were the main ones that survive so now left with only fast cheetahsIII. genetic drifta. only happens in small populationb. change the allele frequency of populationc. Where random events can cause natural selectioni. ex: in a small population of red and green plants all the green plants get destroyed and the red ones survive, now see only red plantsd. founder effect: new environment, few individualse. take a select little group and from them comes a less diverse populationi. amiss population with six fingers, very common to that area, more recessive genes expressedf. bottlenecks: drastic population reductioni. the ones that live do not demonstrate the original DNAii. less gene diversityiii. more dangerous because all similar traits can defend themselves against disastersg. gene flow: migration of fertile individualsh. nonrandom mating: very picky about who they mate withi. sexual selection: certain traits make individuals more attractiveii. now see what traits are passed downiii. typically female choosing1. intrasexuala. same sexb. ex:two males competing with each otherc. sperm competition2. intersexual/matera. different sexesb. male and femalec. mainly females choosing the