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Homework #1 due 2/7 Bonus #1 due 2/28 CB 17.4 Combinations of 3 nucleotides code for each 1 amino acid in a protein. CB 5.25 Genes contain the information to make RNA and/or proteins. The information in genes is what to make and when to make it. Protein What makes us who we are? Imprinting: exposure to movement sets “mother” Human Chromosomes X/Y chromosomes in humans: genes = traits What makes us who we are? Nature and Nurture Twin studies have been used to determine the heritability of various traits, but there are some caveats. Correlation of weight and relatedness Correlation of weight (BMI) % Biological siblings 34 Parents and children living together 26 Identical twins reared together 80 Fraternal twins reared together 43 Identical twins reared apart 72 Adopted children and parents 4 Unrelated children living together 1 *But food preference shows little genetic correlation Intelligence Correlation of IQ Inheritance : The same person tested twice Identical twins reared together Identical twins reared apart Fraternal twins reared together Biological siblings Parents and children living together Parents and children living apart Adopted children living together Unrelated people living apart % 87 86 76 55 47 40 31 0 0 When the environment is equal (everyone has access to resources), genetic differences are magnified. When environments are different (only a few have access to resources), environmental differences are magnified. Proof or disproof? Correlation of IQ Inheritance : The same person tested twice Identical twins reared together Identical twins reared apart Fraternal twins reared together Biological siblings Parents and children living together Parents and children living apart Adopted children living together Unrelated people living apart % 87 86 76 55 47 40 31 0 0 Can we see a genetic basis for complex behaviors? Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Oxytocin and Vasopressin (hormones) Water/salt balance Contraction of womb and milk production Encourages bonding between individuals Hormones are molecules produced in one cell and signal another. Oxytocin and Vasopressin (hormones) Water/salt balance Contraction of womb and milk production Encourages bonding between individuals Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Voles Prairie • Monogamous • Both parents care for young Montane • Nonmonogamous • Mother cares for young briefly Same levels of oxytocin and vasopressin Hormones are molecules produced in one cell and signal another. Voles Prairie • Monogamous • Both parents care for young Montane • Nonmonogamous • Mother cares for young briefly Same levels of oxytocin and vasopressin • More receptors • Less receptors Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Same levels of oxytocin and vasopressin • More receptors • Less receptors Inject hormone into brain •? • ? Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Same levels of oxytocin and vasopressin • More receptors • Less receptors Inject hormone into brain • Monogamous • Nonmonogamous Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Same levels of oxytocin and vasopressin • More oxytocin • Less oxytocin receptors receptors Block receptors •? • ? Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Same levels of oxytocin and vasopressin • More oxytocin • Less oxytocin receptors receptors Block receptors • Nonmonogamous • Nonmonogamous Voles Prairie • Monogamous • Both parents care for young Montane • Nonmonogamous • Mother cares for young briefly Same levels of oxytocin and vasopressin • More oxytocin • Less oxytocin receptors receptors Increase levels of receptors (genetically) in ventral pallidum • Monogamous • Monogamous Why might these voles use different reproductive strategies? Prairie voles Montane voles • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Why might these voles use different reproductive strategies? Prairie voles: Montane voles: Resource poor Resource rich habitat habitat • Monogamous • Nonmonogamous • Both parents care • Mother cares for for young young briefly Children of alcoholic parents are likely to become alcoholics… Nature or Nurture? Homework #1 due 2/7 Bonus #1 due 2/28