Biodiversity and Evolution – Causes of Species Extinction

Vocabulary flashcards summarizing major terms and concepts about biodiversity, species extinction, and environmental issues discussed in the lecture.

Biodiversity (Biological Diversity)

The total variety of all living organisms on Earth and the habitats in which they exist.

Extinction

The complete disappearance of a species when its last individual dies.

Species

A distinct group of organisms that share common characteristics and can interbreed.

Ecosystem

A community of living organisms interacting with their physical (abiotic) environment through nutrient cycles and energy flows.

Population

Members of the same species living in a specific area at the same time.

Community

All the populations of different species living and interacting in a particular area.

Index of Diversity (I.D.)

A measure of species diversity in a community; calculated as number of species × number of runs ÷ number of trees.

Population Density

Number of individuals per unit area or volume.

Limiting Factor

Any environmental condition that restricts population growth, helping maintain ecosystem balance.

Carrying Capacity

The maximum population size an environment can sustain indefinitely.

Endangered Species

A species whose population is so small it is at high risk of extinction.

Threatened Species

A species experiencing rapid decline that may soon become endangered.

Deforestation

The large-scale removal of trees, often leading to habitat loss and soil erosion.

Illegal Logging

Unauthorized harvesting of trees, contributing to deforestation.

Kaingin Farming

Slash-and-burn agriculture practiced in Philippine uplands, leading to forest loss.

Overharvesting

Excessive removal of plants or animals faster than they can reproduce.

Habitat Destruction

Loss or degradation of the natural environment needed by species to survive.

Pollution

Introduction of harmful substances or energy into the environment.

Water Pollution

Contamination of water bodies by chemicals, nutrients, or waste.

Eutrophication

Nutrient enrichment of water that causes excessive algal growth and oxygen depletion.

Fish Kill

Mass death of fish due to low dissolved oxygen following algal blooms.

Polychlorinated Biphenyls (PCBs)

Toxic industrial chemicals that accumulate in organisms and ecosystems.

Biological Magnification

Increase in pollutant concentration at higher trophic levels in a food chain.

Heavy Metals

Toxic elements such as lead, mercury, and cadmium that pollute water bodies.

Air Pollution

Presence of harmful gases, liquids, or solids in the atmosphere.

Smog

Irritating haze formed when pollutants react with sunlight, water vapor, or dust.

Greenhouse Effect

Natural warming of Earth as atmospheric gases trap outgoing heat.

Global Warming

Long-term increase in Earth’s average temperature due to elevated greenhouse gases.

Climate Change

Broad shifts in weather patterns caused by global warming.

Destruction of Coastal Resources

Damage to coral reefs and mangrove forests through human activities.

Coral Reef

Marine ecosystem built by corals, serving as breeding grounds for many fish.

Mangrove Forest

Coastal wetland forest that protects shorelines and supports marine life.

Dynamite Fishing

Illegal method using explosives that destroys coral reefs and kills marine life.

Muro-ami

Destructive net-pounding fishing technique that damages reef ecosystems.

Acid Precipitation (Acid Rain)

Rain with pH ≤ 5.6 caused by sulfur and nitrogen oxides in the air.

Sustainable Development

Using resources at a rate that does not exceed their natural regeneration.

Tamaraw

Endangered dwarf buffalo endemic to Mindoro, Philippines.

Mouse Deer

Small endangered ungulate native to Palawan, Philippines.

Philippine Deer

Native deer species in the Philippines listed as vulnerable or endangered in many areas.

Philippine Eagle (Monkey-eating Eagle)

Critically endangered raptor endemic to Philippine forests.

Dugong (Manatee)

Marine mammal found in some Philippine waters, endangered due to hunting and habitat loss.

Tarsier

Small primate of the Philippines facing habitat-based threats.

Illegal Wildlife Trade

Capture and sale of animals or plants for profit, contributing to population declines.

Overpopulation

Condition where human numbers exceed the environment’s carrying capacity.

Soil Erosion

Loss of topsoil due to deforestation or poor land use.

Flood

Overflow of water onto land, often worsened by tree loss and poor drainage.

Biotic Factors

Living components of an ecosystem (e.g., plants, animals, microbes).

Abiotic Factors

Non-living environmental components (e.g., temperature, light, water).

Runoff

Water flow that carries pollutants or nutrients from land to waterways.

Food Web

Network of interconnected food chains showing energy flow in ecosystems.