Chapter 17

Legacies of Human Evolutionary History

Chapter Outline

• Evolution of Human Behavior and the Life Course

• Biocultural Evolution and the Life Cycle• Human Impact on the Planet and Other

Life-Forms• Is There Any Good News?• Are We Still Evolving?

Behavioral Ecology

• When these G/wi hunters plan their hunting strategy, they consider many factors in addition to calories expended and acquired.

Behavior Patterns

• A mother with her twins. The one on the left is a boy and is breast-fed. The girl, on the right, is bottle-fed. This illustrates differential treatment of boys and girls and the potential negative effects of bottle-feeding.

Question• Behavioral ecologists would say that our

behaviors reflect our evolutionary history. Which of the following is NOT one of the variables that contribute to human behaviors?

a) Gene combinations.b) All of these contribute to human

behaviors.c) Individual experiences.d) Environment.

Answer: b

• Behavioral ecologists would say that our behaviors reflect our evolutionary history. All of the following contribute to human behaviors: Gene combinations. Individual experiences. Environment.

Life Cycle Stages for Various Animal Species

The Human Life Cycle

1. Prenatal begins with conception and ends with birth.

2. Infancy is when the baby nurses.

3. Childhood is from weaning to puberty.

4. Adolescence is from puberty to the end of growth.

5. Adulthood is the completion of growth.

Diameter of Birth Canal and Head Length and Breadth of Newborns

Question

• Humans have a life cycle phase that other primates don't have. It is:

a) infancy.

b) adolescence.

c) childhood.

d) menopause.

Answer: d

• Humans have a life cycle phase that other primates don't have. It is menopause.

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.

Nutritional Requirements for Growth

• Nutrients needed for growth, development, and body maintenance include: proteins, carbohydrates, fats, vitamins and minerals.

• The amount we need of these nutrients coevolved with foods available to humans throughout evolutionary history.

• The specific pattern of amino acids required in human nutrition reflects an ancestral diet high in animal protein.

Preagricultural, Contemporary, and Recently Recommended Diet

PreagriculturalDiet

ContemporaryDiet

RecentlyRecommended

Total dietary energy (%)

Protein 33 12 12

Carbohydrate 46 46 58

Fat 21 42 30

Alcohol ~0 (7–10) —

Cholesterol (mg)

520 300–500 300

Preagricultural, Contemporary, and Recently Recommended Diet

PreagriculturalDiet

ContemporaryDiet

RecentlyRecommended

Total dietary energy (%)

Fiber (g) 100–150 19.7 30–60

Sodium (mg) 690 2,300–6,900 1,000–3,300

Calcium (mg) 1,500–2,000 740 800–1,500

Ascorbic acid (mg)

440 90 60

Food

• Some people suffer from an overabundance of food (left), while others suffer from tragically insufficient amounts of food.

The Secular Trend in Age at Menarche in Europe

Maximal Life Spans for Selected Species

Organism Lifespan

Bristlecone pine 5,000

Tortoise 170

Rockfish 140

Human 120

Blue whale 80

Maximal Life Spans for Selected Species

Organism Lifespan

Indian elephant 70

Gorilla 39

Domestic dog 34

Rabbit 13

Rat 5

Telomeres• Telomeres are repeated

sequences of DNA at the ends of chromosomes, and the sequences appear to be the same in all animals.

• They stabilize and protect the ends of chromosomes, as they shorten with each cell division, chromosomes eventually become unstable.

Changes in Life Expectancy Due to AIDS in Seven African Nations

Millennium Development Goals

• In 2000, heads of state from almost 150 countries agreed to support goals that help reduce human misery throughout the world.

1. Eradicate extreme poverty and hunger.

2. Achieve universal primary education.

3. Promote gender equity and empower women.

4. Reduce child mortality.

Millennium Development Goals

5. Improve maternal health.6. Combat HIV/AIDS, malaria, and other

diseases.7. Ensure environmental sustainability.8. Build a global partnership for development.

Growth in Protected Areas