ANTH 110 Lecture Notes - Lecture 3: Sewall Wright, Genetic Drift, Allele Frequency
Document Summary
Each reproductive cell carries a random assortment of chromosomes and their respective genes. At fertilization, unique egg and sperm produce a unique offspring produced by the shuffling of the parents" genes. One cause of this shuffling is the random segregation or sorting of chromosomes in meiosis. Another cause of the shuffling of parental genes is crossing-over, the exchange of sections of chromosomes between one chromosome and another. Or it can be defined as: during meiosis, the process by which homologous chromosomes intertwine and exchange segments of their dna. As mentioned, most traits are not mendelian but polygenic and determined by the activity of many genes (skin color as an example) A mutation is a change in the dna sequence that produces an altered gene. Most are believed to be the result of mismatches of the chemical base pairs of the dna (errors in copying) Effects of mutations vary widely and have been the subject of much research (deleterious or adaptive?)
