Ecology Test 2

Coevolution

1. Stable Equilibrium
2. Extinction of 1 or both spp
3. Ecological Diversification
4. Red Queen Dynamics

-->Continuous evolution changes in form of arms race
-->Continuousevolution changes in form of evolutionary cycles

Ex: Evo arms race

Newt: neurotoxin production
Snake: Evolves graduate resistance

--> Inc potency of toxin

Large Predators --> Large prey
Small Pred --> Small Prey

Body size of prey/pred cycle

theoretical

Ex: test of coevolution (Pred/Prey)

Control: Fly progeny (Host) cannot evolve
---> Cont addition new hosts

Exp: Host progeny remain in cage
---> Population responds to parasite (evolution

Exp flies can resist wasps better

Ex: test of coevolution (Competition)

Blowfly = originally worse competitor, but eventually out-competed housefly

Ex: coevolution in field

1st Myxoma introduction: 99.8% mortality

Myxoma: dec lethality --> Chronic infection

Consequence of coevolution of competing species

Consumes tissue or body fluids of host

Pathogens: disease-causing parasites

1. Endoparasites
2. Ectoparasites

Intracellular - in cell
Intercellular - in body cavities
tapeworm

Live outside of Host

e.g. Dodder (plant), Tick

Ex: parasite biomass in ecosystem

% parasite biomass/host: low
Biomass density of parasite: comparable to major groups of free-living animals

1. Change Host Behavior
2. Extinction of Host
3. Change Host Population Dynamics
4. Change Outcomes of Competition Interactions
5. Affects Predation
6. Changes Abiotic environment