Lecture 3. Heredity and Environment Prenatal Development Birth. Heredity and environment. The case of intelligence. Charles Darwin. Observed that most organisms reproduce at tremendous rates, yet populations remain nearly constant.
Heredity and Environment
The case of intelligence
From a zygote, a single cell, the size of a period in your book, to 2 billion cells and weighing over 3kgs.
The period that begins 2 months after conception and lasts, on average, 7 months
Both can have possible effects on the fetus.
A tragic example is with the tranquilizer thalidomide, prescribed in the early 1960s.
Mothers do not have to be chronic drug users for the fetus to be harmed.
Taking the wrong drug at the wrong time is enough to physically handicap offspring for life.
FDA recommends either no caffeine or very little.Nonprescription Drugs that Can Function as Teratogens
Defective limbs, face, and heart
Below average intelligence, with some cases of mental retardation
Adults with FAS found to have a high incidence of mental disorders, such as depression or anxietyHeavy Drinking during Pregnancy
There exists a higher incidence of preterm births and lower birthweights.Nicotine
Radiation: nuclear environments, X-rays, computer monitors
Chemicals: carbon monoxide, mercury, lead, pesticides, PCBs
Heat: saunas, hot tubs
When a pregnant woman experiences intense fears, anxieties, and other emotions, physiological changes occur.
These affect the fetus through, for example, restricting blood flow to the uterine area depriving the fetus of adequate oxygen.Effects of Stress on Pregnancy
The Thirties and Beyond
Women have more difficulty getting pregnant after the age of 30.
As women remain active, exercise regularly, and are careful about their nutrition, their reproductive systems may remain healthier at older ages.The Thirties and Beyond
When fathers have a diet low in vitamin C, their offspring have a higher risk of birth defects and cancer.
Fathers’ smoking during pregnancy may lead to lower birthweight and potential for their offspring developing cancer.
Older fathers may place their offspring at risk for certain birth defects, such as Down syndrome and dwarfism.Paternal Factors