Biodiversity Study Notes

General Science July 28, 2025 4 min read

What is Biodiversity?

Definition: Biodiversity refers to the variety and variability of life on Earth. It encompasses all living organisms, their genetic differences, and the complex ecosystems they form.
Levels:
- Genetic Diversity: Variation within species (e.g., different breeds of dogs).
- Species Diversity: Variety of species in a habitat (e.g., rainforest vs. desert).
- Ecosystem Diversity: Different habitats, communities, and ecological processes (e.g., coral reefs, wetlands).

Library Analogy: Imagine biodiversity as a library. Each book represents a species, and the words within are genetic variations. Losing a species is like losing a book; losing genetic diversity is like losing pages from many books.
Human Brain vs. Stars: The human brain has more neural connections (~100 trillion) than stars in the Milky Way (~100 billion). Similarly, Earth’s biodiversity is interconnected in ways that are complex and vast, with each species playing a role in the ecosystem—like neurons in the brain.
Jenga Tower: An ecosystem is like a Jenga tower; each block is a species. Removing blocks (species) weakens the structure, risking collapse.
Rainforest Example: The Amazon hosts ~10% of known species, each contributing to functions like carbon cycling, water purification, and climate regulation.

Ecosystem Services:
- Pollination: Bees, bats, and birds pollinate crops.
- Water Purification: Wetlands filter toxins.
- Climate Regulation: Forests sequester carbon.
Economic Value: Biodiversity supports agriculture, pharmaceuticals, and ecotourism.
Resilience: Diverse ecosystems recover faster from disturbances (e.g., disease, climate events).

Edward O. Wilson (1929-2021): Known as the “father of biodiversity,” Wilson pioneered research on species interactions, conservation, and coined the term “biophilia”—the innate human affinity for nature.
Key Contributions: Advocated for the protection of half the Earth for nature (“Half-Earth Project”).

Citation: Leclère, D., et al. (2020). “Bending the curve of terrestrial biodiversity needs an integrated strategy.” Nature, 585, 551–556.
- Findings: Global biodiversity loss can be reversed by combining conservation, sustainable production, and consumption changes.
- Implication: Strategies must integrate land use, food systems, and policy reforms.

Misconception 1: “Biodiversity only matters in rainforests.”
- Fact: All ecosystems, including urban areas and deserts, have unique biodiversity.
Misconception 2: “Extinction is natural; human impact is negligible.”
- Fact: Current extinction rates are 100–1,000 times higher due to human activities (habitat destruction, pollution).
Misconception 3: “Genetically modified organisms (GMOs) always reduce biodiversity.”
- Fact: Effects depend on context; some GMOs can reduce pesticide use, benefiting non-target species.
Misconception 4: “Biodiversity is only about the number of species.”
- Fact: Genetic and ecosystem diversity are equally crucial.

Genetics: DNA sequencing reveals hidden diversity and evolutionary relationships.
Climate Science: Biodiversity loss affects carbon cycling and climate feedbacks.
Economics: Ecosystem services are valued in natural capital accounting.
Medicine: Many drugs (e.g., penicillin, cancer treatments) originate from wild species.
Technology: Biomimicry (design inspired by nature) leads to innovations (e.g., Velcro from burrs, aerodynamic designs from bird wings).
Sociology & Ethics: Conservation involves indigenous knowledge, equity, and justice.

Conservation vs. Development: Balancing human needs (food, housing) with habitat protection.
Bioprospecting: Fair sharing of benefits from genetic resources, especially with indigenous communities.
Extinction Responsibility: Ethical obligation to prevent species loss caused by human actions.
Animal Rights: Debates on the moral status of non-human species.
Intergenerational Justice: Preserving biodiversity for future generations.

Habitat Loss: Deforestation, urbanization, agriculture expansion.
Climate Change: Alters habitats, migration patterns, and species interactions.
Pollution: Plastics, pesticides, and heavy metals disrupt ecosystems.
Overexploitation: Overfishing, hunting, and logging.
Invasive Species: Non-native species outcompete or prey on native ones.