ANTH 110 1nd Edition Lecture 9 Outline of Last Lecture I. Pleiotropy II. Variations on Standard Inheritance Patterns for Mendelian Traits A. CodominanceB. Incomplete DominanceC. Sex Linked TraitsD. Linked Traits III. PigmentOutline of Current Lecture I. Factors That Can Produce Variation II. Understanding Allele Frequency Current Lecture I. Factors That Can Produce Variation There are multiple factors that can produce variation. Variation is when the allele frequency is changed. Anything like pandemics and natural disasters can affect frequency variation. - Mutation in DNA- Genetic migration (or gene flow)Genetic migration, as the name implies, involves immigration and migration. We carry our alleles with us and share them with other populations. Gene flow decreases variation between populations (Because there is so much swapping being done, it balances out). It increases variation within a 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 drifGenetic drif is when a small population leaves to colonize an another area. Over time, the population will grow in size. There is a change in genetic variation from original population. Some major event can occur that impacts a small population and creates genetic drif. This event would be referred to as the bottleneck effect. Genetic drif increases variation between populations and decrease variation within a population.The Amish are an example of genetic drif. - Natural SelectionNatural Selection, as previously discussed in class, is when advantageous allele variations that promote reproductive success are selected. II. Understanding Allele Frequency Example: Let's say a portion of the class has gray, flaky earwax while another portion have yellow sticky. Since gray, flaky earwax is homozygous recessive, then those students have two lower case e's. If there are 50 people with gray, flaky earwax, there are a total of 100 alleles (ee) here. There are 100 little e's. If 75 are heterozygous for yellow, sticky earwax (Ee), we have 75 little e's and 75 big E's. If 25 are homo dominant (EE), we have 50 big E's. Total = 125 E's (42%) and 175 e's (58%) This data shows the allele frequency. A change in allele frequency is micro-evolution. Allele frequency change is not a speciation event, but it could give rise to speciation over time. This would be macro-evolution, or
View Full Document
Unlocking...