π Animals in Nature and Human Life
Conservation & Domestication β Grade 7 Biology
π± Part 1: Biodiversity β The Foundation
Biodiversity refers to the variety of all living organisms in our natural world. A healthy, balanced ecosystem is essential to support human life, providing food, water, and shelter.
Biodiversity exists at three levels:
𧬠Genetic Diversity
Variation in genes within a species. Example: different dog breeds all belong to Canis lupus familiaris but look very different.
π¦ Species Diversity
The number of different species in an area. A coral reef has far more species diversity than a parking lot.
ποΈ Ecosystem Diversity
The variety of ecosystems on Earth β forests, deserts, oceans, wetlands β each supporting unique communities of life.
π Part 2: Domestication β Shaping Animals Over Generations
What Is Domestication?
Domestication is a multi-generational mutualistic relationship in which humans take over control and care of another species to obtain a steady supply of resources such as meat, milk, or labor. The process is gradual, affects genes for behavior (making animals less aggressive), and reduces the organisms' ability to survive in the wild.
Timeline of Key Domestication Events
Dogs are generally recognized as the earliest known domesticated animals, derived from wolves, with the earliest known dog burial dating to 12,000β10,000 BCE. Sheep were among the first livestock domesticated (11,000β15,000 years ago), cattle followed around 10,000β15,000 years ago, and horses were domesticated roughly 5,000 years ago.
What Makes a Species Suitable for Domestication?
Not every animal can be domesticated. Key traits include:
Impact of Domestication on Human Civilization
Domestication coincided with the advent of agriculture, enabling sedentary lifestyles and the growth of civilizations. However, living closely with animals also introduced zoonotic diseases β illnesses that jump from animals to humans (e.g., tuberculosis from cattle, influenza from pigs).