14: How do species coexist?

Possible outcomes of competition

Exclusion (one species persists, others decline to zero)

Coexistence (both species maintain populations over time)

Divergence (traits or resource use shift, reducing overlap)

When does competition lead to divergence?

ONLY IF TRAITS CHANGE!!!

Mechanism vs Fundamental/Realized niches

Mechanism is when you are testing together vs apart to see if changing niche

Niche Partitioning

Competition reducing each species to occupy a different realized niche

Does niche overlap show competition?

No, it only predicts competition, but could be something else

Coevolution

When the species BOTH CHANGE TRAITS when together

What else can weaken competition?

Partitioning, exclusion, spatial refuges, or temporal variation

Niche

Evidence-based claim about conditions, resources, and interactions that allow persistence

When is coexistence stronger?

When it is stable so each species can recover from rarity

Can trait differences in sympatry support character displacement?

Yes, but needs alternative explanations for strong claims

Character displacement

when traits are displaced when multiple species coexist in one area (everyone partitioning)