ANT101H5 Lecture Notes - Lecture 3: Gregor Mendel, Population Genetics, Mendelian Inheritance
ANT101 - Lecture 3: Modern Evolutionary Theory & Population Genetics Jan/13/14
Gregor Mendel (1822-1884)
- Father of modern genetics
- Provided mechanisms of natural selection through breeding experiments with peas
- Determined how one trait passed from one generation to the next
- Principle of Segregation
o Each unit pair separates in gamete production, so that each gamete contains 1
member of each pair
▪ During fertilization individual units come together
- Principle of Independent Assortment
o Units (genes) that code for different traits assort independently of each other
during gamete formation and recombine in offspring
Genes
- Unit of heredity – controls trait
- Portion of DNA molecule
- Contains several base pairs to direct the production of a particular protein
Alleles
- Express the traits provided by genes
- Alternate forms of a single gene
- Important to remember:
o Natural Selection operates on the features in an individual, but populations evolve
▪ Fitness: the relative reproductive success of individuals
• Will change as the environment changes
o Evolution acts on a population
▪ Change in allele frequency from one generation to the next in a
population
Mendelian Inheritance
- Homozygous: same variants of a trait (alleles) come together
- Heterozygous: different variants of a traits (alleles) come together
- Recessive: trait not expressed in heterozygous state
- Dominant: trait expressed in the heterozygous state
- Genotype: genetic makeup of an individual
- Phenotype: observable physical characteristics of an organism
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Document Summary
Ant101 - lecture 3: modern evolutionary theory & population genetics. Provided mechanisms of natural selection through breeding experiments with peas. Determined how one trait passed from one generation to the next. Principle of segregation: each unit pair separates in gamete production, so that each gamete contains 1 member of each pair, during fertilization individual units come together. Principle of independent assortment: units (genes) that code for different traits assort independently of each other during gamete formation and recombine in offspring. Contains several base pairs to direct the production of a particular protein. Homozygous: same variants of a trait (alleles) come together. Heterozygous: different variants of a traits (alleles) come together. Recessive: trait not expressed in heterozygous state. Dominant: trait expressed in the heterozygous state. Connected by 4 base pairs (adenine thymine and guanine cytosine) Sides made up of 2 strands of alternating sugars & phosphates, Proteins are made up of strands of amino acids (20 different amino acids)
