Anthro2050 1st Edition Lecture 12 Outline of Last Lecture I Non Mendelian Genetics Outline of Current Lecture II Evolutionary Forces Sources of Variation III Introduction to Primates Current Lecture Variation is the raw material that evolution acts on Individual variation Independent assortment crossing over and mutation Mutation the only thing that produces new variations everything else is just the reshuffling of existing variations Mutation is a copying error when DNA is replicated Point Mutation the changing of a single nucleotide Deletion inserting taking out of nucleotides Mutations can be good or bad but most are just neutral Actual rates of mutation are difficult to determine considering that the majority are neutral and that 70 of pregnancies end in miscarriage Only 15 occur when the mother knows she is pregnant the 70 is for all pregnancies known and unknown The rough estimate is there are between 1 to 100 mutations per 1 million sex cells While neutral mutations have no real effects if a mutation is bad it can be harmful Population Variation natural selection genetic drift gene flow The ways variation leads to evolution Gene Flow through immigrants from one population to another introducing new alleles to a population Genetic Drift random sampling and fluctuating of gene frequencies from one generation to the next Seen frequently in very small populations Founder Effect a small subset of a population breaks off to make their own population Suddenly and traits not in these individuals are not in the new populations and traits they do have become more common than in the original population 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 Genetic drift can alter allele frequencies in a population and inbreeding as well alters allele frequencies increasing homozygosity for recessive genes Introduction to Primates Genetically primates are the closest relatives to humans Humans homo sapiens are primates more specifically Great Apes Therefore it is important for us to learn about primates as they have many similarities with humans There is a huge diversity among primates as well including shape and size and diet although the basic morphology is pretty much the same Different types of mammals based on reproduction Monotremes egg laying mammals Marsupials infants complete development in an external pouch Placental fetus develops in a longer gestation inside the body and are raised on mothers milk after birth There are over 4 000 species of mammals and approximately 250 species of primates Strepsirrhines small more similar to ancient primate ancestors than modern primates New World Monkeys From South America Old World Monkeys From Africa Asia and a tiny bit of Europe Apes Greater Lesser Africa Larger than monkeys and have no tails
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