Biodiversity

Biodiversity refers to the variety and variability of life forms within a given species, ecosystem, or planet. It encompasses three main levels:

• Genetic diversity: The genetic variation that occurs among individuals in a population.
• Species diversity: The variety of different species within an area.
• Ecosystem diversity: The variety of ecosystems within a region.

Key Concepts

• Endemism: The degree to which organisms are unique to and exclusive for a defined geographic location, such as an island or other isolated areas like the Galápagos Islands.
• Conservation biology: A branch of biological science that aims to conserve endangered species and their habitats.
• Ecological niche: The role or job of a species in its environment; how it makes a living.

Related Topics

• shark-evolution
• cartilaginous-fish

New Note Integration

The Golden Age of Shark Evolution and Bizarre Adaptations

• Date: 2026-04-10
• Clip title: How Sharks Lost Their Buzzsaws, Anvils, and Spikes
• Author / channel: pbs-eons
• URL: https://www.youtube.com/watch?v=4ihYiTOIBT0

Summary

The video explores the “Golden Age of Sharks,” a period characterized by incredibly diverse and often bizarre cartilaginous fish, including the ancestors of modern sharks, rays, and chimaeras like the ratfish. This era preceded the dominance of iconic predators like the Great White.

2026 04 10 The Golden Age of Shark Evolution and Bizarre Adaptations