PSY354H5 Chapter Notes - Chapter 2: Cambrian Explosion, Asexual Reproduction, Sexual Selection
Document Summary
Evolution: the change in the genetic makeup of living populations over time. Haploid gametes produced by meiosis: mammals reproduce sexually, vertebrates and plants can produce sexually or asexually, adaptive. Advantages of sexual reproduction: don"t know which of these hypothesis are correct. Measured rate at which harmful mutations accumulated in two lineages of water fleas. Asexual lineage accumulated harmful mutations at a higher rate than sexual. Having off springs with different combinations of genes is useful because they have different ways of utilizing the resources available in the environment. Useful dealing with environmental changes: ex. Less than 3% of all corn kernels are a result of self-pollination: in animals , behavioural mechanisms prevent self-insemination. Mollusks penis fencing to determine who is the mother: individuals of the same sex can have different roles, ex. Some individuals of one sex can be temporally or permanently sterile : worker bees are sterile while a selected few are breeders.
