20.4 Plants in Human Culture

KEY CONCEPT Humans rely on plants in many ways.

20.4 Plants in Human Culture

Agriculture provides stable food supplies for people in permanent settlements.• Botany is the study of plants.• Ethnobotany explores how people in different cultures use

plants.

20.4 Plants in Human Culture

• People started planting for harvest about 10,000 years ago.

Teosinte

– wild species “tamed” through artificial selection– farming requires people to stay in one place– farming helped more socially complex centers develop

20.4 Plants in Human Culture

Plant products are important economic resources. • Plant products have been traded for thousands of years.

– spices commonly used as currency in Middle Ages

– spurred seafaring expeditions in 1400s and 1500s

20.4 Plants in Human Culture

• Plant products contribute to economy on a global scale today.

– grains, coffee, sugar, cotton, forest products– billions of dollars of plant products traded each year

20.4 Plants in Human Culture

Plant compounds are essential to modern medicine.• Pharmacology is the study of drugs and their effects on

the body. • Many drugs are derived from plants.

– Salicin from willow trees is used in aspirin. – Alkaloids are potent plant chemicals that contain

nitrogen.– Alkaloids such as taxol have anti-cancer properties.

20.4 Plants in Human Culture

• Some medical research focuses on properties of plant compounds.

– studies plants used medicinally in traditional cultures

– develop synthetic drugs based on plant compounds