All Flashcards
Define Island Biogeography Theory.
Explains how island size and location affect species number, balancing immigration and extinction.
What are endemic species?
Species native to a specific area, often specialists, vulnerable to change.
Define invasive species.
Non-native species that spread rapidly, causing harm, often generalists.
What is adaptive radiation?
Evolution of many species from a single ancestor, each filling a different niche.
Define immigration in IBT.
The arrival of new species to an island.
Define extinction in IBT.
The dying out of species already present on an island.
Define species richness.
The number of different species represented in an ecological community, landscape or region.
What is a generalist species?
A species that can thrive in a wide variety of environmental conditions and make use of a variety of different resources.
What is a specialist species?
A species that can thrive only in a narrow range of environmental conditions or has a limited diet.
Define ecological niche.
The role and position a species has in its environment; how it meets its needs for food and shelter, how it survives, and how it reproduces.
What is the relationship between island size and extinction rates?
Larger islands support larger populations, reducing extinction risk.
How does distance from the mainland affect immigration rates?
Closer islands are easier to reach, leading to higher immigration.
Why are endemic species vulnerable?
They are often specialists with narrow niches, susceptible to changes.
Why do invasive species thrive?
Lack of predators, generalist nature, and rapid reproduction aid their success.
How does IBT relate to conservation?
IBT principles guide reserve design to maximize species richness.
Explain the equilibrium point in IBT.
The point where immigration and extinction rates are equal, determining species richness.
What factors determine species richness?
Island size, distance from mainland, immigration, and extinction rates.
Describe the impact of invasive species on endemic species.
Invasive species outcompete and displace endemic species, potentially leading to extinction.
How does habitat diversity affect species richness?
Greater habitat diversity supports a wider range of species, increasing richness.
What role does geographic isolation play in evolution?
It allows populations to evolve independently, leading to unique species.
What is the effect of introducing an invasive species?
Displacement of endemics, habitat alteration, economic costs.
What causes adaptive radiation?
Limited immigration, natural selection, geographic isolation.
How does habitat loss affect endemic species?
Increases their risk of extinction due to limited suitable habitat.
What are the effects of invasive species on ecosystem equilibrium?
Disrupts equilibrium by outcompeting native species, altering habitats, and causing economic damage.
How does geographic isolation drive evolution?
It allows populations to evolve independently, leading to unique adaptations and speciation.
How does increased competition affect extinction rates?
Increased competition leads to higher extinction rates as species struggle for resources.
How does the lack of natural predators affect invasive species?
Allows their populations to explode, leading to rapid spread and displacement of native species.
What is the effect of habitat alteration by invasive species?
Changes the structure and function of ecosystems, impacting native species and ecosystem services.
How does climate change affect endemic species?
Increases their vulnerability due to their narrow ecological niches and sensitivity to environmental changes.
How does natural selection affect species on islands?
Different environmental pressures lead to different adaptations, driving species divergence and adaptive radiation.