Chapter 13 Anthropological Perspective on the Human Life Course

Chapter Outline Fundamentals of Growth and Development Nutritional Effects on Growth and Development Other Factors Influencing Growth and Development The Human Life Cycle

Growth and Development Growth refers to an increase in mass or number of cells. Development refers to differentiation of cells into different types of tissues.

Stature Influenced by genetics, health and nutrition. Children with good health and adequate nutrition are more likely to reach the genetic potential for height. Members of higher socioeconomic groups tend to be taller, reflecting the impact of economic status on growth and development.

Brain Growth At birth the brain is about 25% of its adult size. Six months after birth it has doubled in size and reached 50% of its adult size. By age 5, the brain has reached 90% of its adult size. By age 10 the brain is at 95% of its adult size.

Preagricultural, Contemporary, and Recently Recommended Diet Preagricultural Diet Contemporary Diet Recent Recommendations Total dietary energy (%) Protein3312 Carbohydrate46 58 Fat Alcohol~0(7–10)— Cholesterol (mg)520300– Fiber (g)100– –60 Sodium (mg)6902,300–6,9001,000–3,300

Five Basic Nutrients Proteins are the major structural components. Carbohydrates are an important source of energy. Lipids include fats and oils. Vitamins speed up the chemical reactions necessary for running the body. Minerals contribute to normal functioning and health.

Evolution of Nutritional Requirements Nutritional needs evolved according to the foods available to our evolutionary ancestors. We inherited the ability to digest animal protein from our mammalian forebears. Early primates evolved the ability to digest plants. Our ape-like ancestors were fruit-eaters and passed on their ability to process fruit to us.

Undernutrition Undernutrition means an inadequate quantity of food. Between 16 and 63% of the world's population is undernourished.

Malnutrition Refers to an inadequate amount of key elements in the diet. Greatly affects reproduction and infant survival. – Malnourished mothers have more difficulty producing healthy children. – Children born of malnourished mothers are behind in most aspects of physical development.

Factors Influencing Growth and Development Genetics – Environmental factors can influence growth and development, but an individual can not exceed their genetic potential. Hormones – Thyroxine regulates metabolism and aids in body heat production. Growth hormone has an impact on almost every cell in the body.

The Human Life Cycle 1. Prenatal begins with conception and ends with birth. 2. Infancy is the period in which the baby nurses. 3. Childhood is the period from weaning to puberty. 4. Adolescence is the period from puberty to the end of growth. 5. Adulthood is marked by the completion of growth.

Providing for Juveniles Percent Who Survive WeaningAdolescence Lion2815 Baboon4533 Macaque4213 Chimpanzee4838 Human Populations !Kung8058 Yanomamo7350 Paleoindian8650

Onset of Puberty Factors: Genetics Gestational experience Nutrition Disease Activity level Stress

Theories: Nonreproductive Period in Human Females Child-rearing theory - Women are "programmed" to live 12 to 15 years beyond the birth of their last child. Grandmother Theory - Women can provide resources to their grandchildren if their own children are independent. Nonselection Theory - Menopause is an artifact of the extension of the life span.

Life Spans Organism Approximate Maximum Life Span (in years) Bristlecone pine5,000 Tortoise170 Human120 Blue whale80 Indian elephant70 Gorilla39 Domestic dog34 Rabbit13 Rat5