Evolution and Multi-Locus Evolution - Notes

Evolution and Multi-locus Evolution

  • Class Information
    • Course: BIO 3339/5311
    • Date: February 6

Learning Objectives

  • Gene Interactions: Understand its role in phenotypic traits, which can:

    1. Be continuous vs. discontinuous
    2. Be polygenic (traits influenced by multiple genes)
    3. Demonstrate latent variation (hidden genetic potential that can be expressed under certain conditions)

  • Linkage Disequilibrium (LD):

    • Definition: Non-random association of alleles at different loci.
    • Importance: LD can be caused by:
    • Selection
    • Migration
    • Genetic drift
    • Mutation
    • Nonrandom mating
    • Mechanism: Recombination helps in breaking down LD.

Mendel's Laws

  • Law of Segregation:

    • Alleles segregate during gamete formation. Each gamete will carry only one allele for each gene.

  • Law of Independent Assortment:

    • Genes for different traits can segregate independently during the formation of gametes.

Observations on Mendel's Work

  • Mendel's traits were discrete, contrasting with the continuous variation typically observed in most traits today.
  • There's ongoing debate about the compatibility of Mendel's ideas with Darwin's theory of evolution by natural selection.

Hardy-Weinberg Derivation

  • Model Overview:
    • Examines allele frequencies in a non-evolving population to establish a