How can natural selection explain earths diversity?
Three possible outcomes of Natural Selection and this will result in the diversity. 1) A shift in the range of values for a given trait in one direction directional selection) 2) Stabilization of an existing range of values (stabilizing selection) 3) Disruption of an existing range of values (disruptive selection) Directional Selection Over time, allele frequencies shift in one direction Caused by: 1) Environment selects against a particular phenotype (colors that stand out in an environment), or 2) A new mutation/allele may be advantageous in an environment A case of directional natural selection: antibiotic resistance • Antibiotics first came into use in the 1940sMany antibiotics are produced naturally by microorganisms (e.g., penicillin produced by Penicillium –Ascomycetes, Fungi). • The overuse of antibiotics has led to an increase in resistant alleles in bacteria and • Most susceptible bacteria die out and are replaced by resistant forms; these successful alleles further mutate a
