Bonus#1 due 2/24

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

TraitsGenes 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:

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 (BMI)% Identical twins reared together80 Identical twins reared apart72 Fraternal twins reared together43 Biological siblings34 Parents and children living together26 Adopted children and parents 4 Unrelated children living together 1 *But food preference shows little genetic correlation Correlation of weight and relatedness 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 pp 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 twice87 Identical twins reared together86 Identical twins reared apart76 Fraternal twins reared together55 Biological siblings47 Parents and children living together40 Parents and children living apart31 Adopted children living together 0 Unrelated people living apart 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 together80 Identical twins reared apart72 Fraternal twins reared together43 Biological siblings34 Parents and children living together26 Adopted children and parents 4 Unrelated children living together 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 pp 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 Monogamous Both parents care for young Montane Nonmonogamous 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 Monogamous Both parents care for young Montane Nonmonogamous Mother cares for young briefly

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

Hormones are molecules produced in one cell and signal another.

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

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

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

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

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

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

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

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

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

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

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

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

See: (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 editioncgidoi pnas Fetal exposure to smoking can have several affects, including: decreased birth weight increased anti-social behavior

See: (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 editioncgidoi pnas Fetal exposure to smoking can have several affects, including: -decreased birth weight -increased anti-social behavior Are these affects genetic or environmental?

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.

The average birth weight for all babies born to smoking mothers was lower...

Anti-social behavior was only different if the child and mother were related...

Nature and Nurture: Are traits coded for by genes fixed while traits coded for by the environment are under our control?