The ecological and geographic dynamics of extinction: Niche modeling and ecological marginalization

All organisms have a position within an ecosystem. The complete set of living and nonliving factors—including food resources, climate, and terrain—that define the position of a given organism are collectively referred to as the organism’s ecological niche.

Mass ExtinctionMass extinction occurs when many species disappear from Earth in a short period. Throughout Earth’s history, five major mass extinctions have been caused by asteroid impacts, volcanic eruptions, or sudden climate changes. These events drastically reduced biodiversity and led to the evolution of new species over time. Today, scientists believe we are facing a possible sixth mass extinction, driven by human activities such as deforestation, pollution, climate change, and habitat...

Habitat and NicheEvery living organism lives in a specific environment known as its habitat and plays a unique role in that environment, which is called its niche. A habitat is the physical place where an organism lives, like a forest, desert, or ocean. A niche describes how the organism meets its food, shelter, and reproduction needs and interacts with other organisms. Grasping the concepts of habitat and niche enables scientists to investigate species survival, their interactions, and their...

There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...

Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.

Habitat fragmentation describes the division of a more extensive, continuous habitat into smaller, discontinuous areas. Human activities such as land conversion, as well as slower geological processes leading to changes in the physical environment, are the two leading causes of habitat fragmentation. The fragmentation process typically follows the same steps: perforation, dissection, fragmentation, shrinkage, and attrition.