Bonus1 due 224 Genes Traits Genes code for

Bonus#1 due 2/24

Genes Traits Genes code for proteins. These proteins give rise to traits…

Genes Traits Genes code for proteins. These proteins give rise to traits… It is rarely this simple.

What makes us who we are? Nature and Nurture Based on “Nature via Nurture” by Matt Ridley (2003)

Imprinting: exposure to movement (environment) sets “mother”

X/Y chromosomes in humans: genes = traits XY XX

Twin studies have been used to determine the heritability of various traits.

Types of twins: http: //pennhealth. com/health_info/pregnancy/000199. htm

Twin studies have been used to determine the heritability of various traits, but there are some caveats: How many twins have been studied? How different are the environments?

Correlation of weight and relatedness Correlation of weight (BMI) % Identical twins reared together 80 Identical twins reared apart 72 Fraternal twins reared together 43 Biological siblings 34 Parents and children living together 26 Adopted children and parents 4 Unrelated children living together 1 *But food preference shows little genetic correlation The nature of environmental influences on weight and obesity: A behavior genetic analysis. Grilo, Carlos M. ; Pogue-Geile, Michael F. ; Psychological Bulletin, Vol 110(3), Nov 1991. pp. 520 -537. And two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

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 From two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

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 weight (BMI) Identical twins reared together Identical twins reared apart Fraternal twins reared together Biological siblings Parents and children living together Adopted children and parents Unrelated children living together % 80 72 43 34 26 4 1 The nature of environmental influences on weight and obesity: A behavior genetic analysis. Grilo, Carlos M. ; Pogue-Geile, Michael F. ; Psychological Bulletin, Vol 110(3), Nov 1991. pp. 520 -537. And two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

Can we see a genetic basis for complex behaviors?

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for young briefly

Oxytocin (hormone) Water/salt balance Contraction of womb and milk production Encourages bonding between individuals

Hormones are molecules produced in one cell and signal another.

Oxytocin (hormone) Water/salt balance Contraction of womb and milk production Encourages bonding between individuals

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care • Mother cares for young briefly

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin

Hormones are molecules produced in one cell and signal another.

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More receptors • Less receptors

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More receptors • Less receptors Inject hormone into brain • ?

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More receptors • Less receptors Inject hormone into brain • Monogamous • Nonmonogamous

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More oxytocin • Less oxytocin receptors Block receptors • ?

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More oxytocin • Less oxytocin receptors Block receptors • Nonmonogamous

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More oxytocin • Less oxytocin receptors Increase levels of receptors (genetically) in ventral pallidum • Monogamous

Voles Prairie Montane • Monogamous • Nonmonogamous • Both parents care for • Mother cares for young briefly Same levels of oxytocin • More receptors • Less receptors

What might be the basis for these different reproductive strategies? Prairie voles Montane voles • Monogamous • Nonmonogamous • Both parents care • Mother cares for young briefly

What might be the basis for these different reproductive strategies? Prairie voles: Montane voles: Resource poor Resource rich habitat • Monogamous • Nonmonogamous • Both parents care • Mother cares for young briefly

How does evolution work for a behaviors such as monogamy? monogamous bye non-monogamous

How does evolution work for a behaviors such as monogamy? After several generations… monogamous non-monogamous

Fetal exposure to smoking can have several affects, including: • decreased birth weight • increased anti-social behavior See: http: //sciencenow. sciencemag. org/cgi/content/full/2009/203/3? rss=1 (and/or) Disentangling prenatal and inherited influences in humans with an experimental design Frances Ricea, Gordon T. Haroldb, Jacky Boivinb, Dale F. Hayb, Marianne van den Breea, and Anita Thapara PNAS early edition�cgi�doi� 10. 1073�pnas. 0808798106

Fetal exposure to smoking can have several affects, including: -decreased birth weight -increased anti-social behavior Are these affects genetic or environmental? See: http: //sciencenow. sciencemag. org/cgi/content/full/2009/203/3? rss=1 (and/or) Disentangling prenatal and inherited influences in humans with an experimental design Frances Ricea, Gordon T. Haroldb, Jacky Boivinb, Dale F. Hayb, Marianne van den Breea, and Anita Thapara PNAS early edition�cgi�doi� 10. 1073�pnas. 0808798106

In Vitro Fertilization- fertilization occurs in a lab, and then the embryo is implanted into a woman's uterus. Usually the pregnant woman is related to the embryo, but sometimes they are unrelated.