types of species interactions

Species interactions

• all species interact

• Interactions are incredibly diverse

• Inter = diff species

• Intra = same species

• Pairs of species interact → their evolution is tied together

Pairs of Species Interact

• Classification

  • Interactions between two species can…

    • Benefit (+)

    • Harm (-)

    • Have no effect (0)

  • …On each of them

• Symbiosis: when the interaction (+/-/0) is close and long term

Mutualism

Effects on ~

Species 1: +

Species 2: +

Antagonism

Effects on ~

Species 1: -

Species 2: +

Competition

Effects on ~

Species 1: -

Species 2: -

Commensalism

Effects on ~

Species 1: +

Species 2: 0

Amendslism

Effects on ~

Species 1: -

Species 2: 0

Competition

• Both species do worse when together

• In nature, resources are limited in availability

• Resource use by one individual that reduces its availability to others

  • Mates

  • Space

  • Food

    
    

Commensalism

• One species does better in the presence of the other

• The other species is unaffected when together

Amensalism

• One species does worse when together, the other is unaffected

• Many interactions between humans, plants, and wildlife are amensal

Antagonism

One does worse, one does better when together

• Predation

• Hernivory

• Parasitism

Mutualism

• Both do better when together

• Usually an exchange of different things

• Ex. Pollination mutualism

  • Animal gets food, pollen gets moved

• Ex. Seed dispersal mutualism

  • animal gets good, plant gets seeds dispersed to germinate

• Ex. Protection mutualism

  • One animal gets food, other gets protection from enemies (or parasites removed)

• Ex. Nutrition mutualism

  • Plants get nutrients, bacteria get habitat

• Not “being nice” to each other: mutualism is based on evolutionary adaptations where benefit of receiving a service outweighs cost of performing a service to the other