APES - Unit 2 vocab

adaptation

A trait that helps an organism survive or reproduce better in its environment.

allopatric speciation

When one species splits into two because they got physically separated.

artificial selection

Humans choosing which organisms breed to get certain traits (like dog breeds).

bottleneck effect

When a population gets super small suddenly, and its genetic diversity drops a ton.

climax community

The stable, final stage of succession where the ecosystem doesn’t change much anymore.

disruption

Any event that messes up an ecosystem’s normal conditions.

ecological niche

Everything an organism needs and does in its environment (its “role”).

ecological tolerance

The range of conditions an organism can handle before it gets stressed or dies.

ecosystem services

Useful things nature does for us, like filtering water or giving us food.

endemic species

A species that only exists in one specific place and nowhere else.

episodic disturbance

A disturbance that happens every once in a while, not regularly (like a hurricane).

evolution

Change in a population’s genes over time.

extinction

When a species disappears completely.

fitness

How well an organism survives and reproduces compared to others.

founder effect

When a small group starts a new population and carries only a tiny bit of the original genetic diversity.

fundamental niche

All the conditions a species could live in if nothing limited it.

gene flow

Movement of genes between populations when individuals migrate and reproduce.

generalist species

Species that can live basically anywhere and eat a lot of different things.

genetic diversity

How many different genes and traits exist within a population.

genetic drift

Random changes in gene frequencies, especially in small populations.

geographic range

The total area where a species naturally lives.

habitat diversity

How many different habitat types exist in an ecosystem.

hotspots/biodiversity hot spot

Places with tons of species but also a lot of threats/habitat loss.

indicator species

Species that tell us something about the health of an ecosystem.

intermediate disturbance hypothesis

Ecosystems with moderate levels of disturbance have the most biodiversity.

island biogeography

Theory explaining species richness on islands based on size and distance from mainland.

keystone species

A species that has a huge impact on the ecosystem relative to its low abundance.

mass extinction

A big global event where tons of species go extinct in a short time.

macroevolution

Big evolutionary changes that lead to new species or groups.

microevolution

Small changes in allele frequencies within a population.

mutation

A random change in DNA that can create new traits.

native species

Species that naturally occur in an area.

natural selection

Organisms with better traits survive/reproduce more, passing those traits on.

periodic disruption

A disturbance that happens on a regular, predictable cycle.

pioneer species

First species to show up after a disturbance (like mosses and lichens).

population bottleneck

Another term for bottleneck effect: population drops dramatically, losing diversity.

primary succession

Succession starting on bare rock with no soil.

provisions

Ecosystem services that give us actual resources like food, water, timber.

random disruptions

Disturbances that happen without any pattern or predictability.

realized niche

The actual conditions where a species lives because of competition and limits.

resilience

How fast an ecosystem bounces back after a disturbance.

resistance

How well an ecosystem can withstand a disturbance without changing much.

secondary succession

Succession that happens where soil is still present after a disturbance.

specialist species

Species that have very specific habitat or diet needs.

species area-curve

Shows how bigger areas usually support more species.

species diversity

A mix of species richness and species evenness.

species evenness

How evenly the individuals are spread among the different species.

species richness

The number of different species in an ecosystem.

sympatric speciation

When new species form without a physical barrier separating them.

CITES

International treaty that protects endangered species by regulating wildlife trade.

Endangered Species Act

U.S. law that protects threatened and endangered species and their habitats.