Lecture 2 Genetics and Prenatal Development DEP 2004 & 2004H Human Development Across the Lifespan...

Lecture 2Genetics and Prenatal

DevelopmentDEP 2004 & 2004H Human Development Across the Lifespan

Erica Jordan, Ph.D., University of West FloridaSchool of Psychological and Behavioral Sciences

Lecture Guiding Questions

How do genes influence behaviors?

What are the major stages of prenatal development?

What risks factors are associated with prenatal development?

Adapted from Arnett's (2012) Human Development: A Cultural Approach &

Kail & Cavanaugh's Human Development: A Life-Span View

How do genes influence behaviors?

Behavior Genetics: the branch of genetics that deals with inheritance of behavioral and psychological traits

Traits controlled by a single gene typically produce one of two outcomes (either - or)

Most behavioral and psychological traits are more complex Possible phenotypes fall along a continuum or have multiple

possibilities Result from the instructions/interactions of separate genes—

polygenic inheritance Influence of each specific gene involved is very difficult to

determine



Research Methods Commonly Used to Study Behavioral

Genetics

Twin studies Comparison of monozygotic twins (identical and from

the same fertilized egg) and dizygotic twins (fraternal and from different eggs).

Characteristics commonly shared by monozygotic twins that are often different in dizygotic twins are typically inherited.



Adoption studies Comparing adopted children alongside their

biological parents and their adoptive parents.

Studying DNA Taking samples of DNA from individuals who differ in

some way then examining the DNA for differences.



More about the way genes influence

behaviors:

1. The behavioral consequences of genetic instructions depend on the environment in which those instructions are implemented.

- A specific genotype does not always lead to the same phenotype.

- Reaction range—range of potential phenotypes for a specific genotype.

- Heritability estimate—extent to which genes are responsible for the differences among people; range from 0 to 1.00.



2. Heredity and environment interact dynamically throughout development.

3. Genes can influence the kind of environment to which a person is exposed.

- Responses from others

- Niche picking—refers to how people seek out their own environments based on their interests and strengths



4. Environmental influences typically make children within a family different.

- Siblings often have similar experiences

- Nonshared environmental influences also occur



The Theory of Genotype Environment Effects

Passive genotype environment effects

Evocative genotype environment effects

Active genotype environment effects



From Conception to Birth

Prenatal Development The changes that turn a fertilized egg into a

newborn human



Period of the Zygote(Week 1 - 2)

Zygote: fertilized egg



Period of the Embryo(Week 3 - 8)

Begins when zygote is completely embedded in the uterine wall.



Period of the Fetus(Weeks 9 - 38)

Final and longest phase of prenatal development. Begins when cartilage begins to turn to bone and ends at birth.



Common Genetic Disorders

Sickle-cell desease

PKU

Huntington’s disease

Down syndrome

Klinefelter’s syndrome

Turner’s syndrome

XYY complement

XXX syndromeAdapted from Arnett's (2012) Human

Development: A Cultural Approach & Kail & Cavanaugh's Human

Development: A Life-Span View

Risks to Prenatal Development

Parents’ age

Nutrition

Stress

Disease

Drugs

Environmental hazards

Teratogens—agents that cause abnormal prenatal development



Teratogens: Five Principles



Lecture 2 Genetics and Prenatal Development DEP 2004 & 2004H Human Development Across the Lifespan...

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Transcript of Lecture 2 Genetics and Prenatal Development DEP 2004 & 2004H Human Development Across the Lifespan...