Fundamental niche

Realized niche

Character displacement in beak size in poulations of Galapagos finches

€

dN prey

dt= rN prey 1−

N prey

K− cN pred N prey

⎛

⎝ ⎜

⎞

⎠ ⎟

# prey predator kills; on predator efficiency = c,

# prey, # predators

€

dN pred

dt= b(cN pred N prey ) − dN pred

# kills

Efficiency of converting kills to new predators

Death rate of predators in absence of prey

Type I functional response

Daphnia magna consuming yeast cells

Type IIFunctional response

Parasitoid that attacks cocoons of pine sawfly

Type III functional response

Cryptic coloration in the flounder, which is capable of changing their color and pattern rapidly to match bottom sediments.

Cryptic coloration the walking stick, which feeds on leaves.

Aposematism:Monarch

Batesian mimicry:Viceroy

Müllerian mimicry

Effects of grazing by beetle (Gastrophysa viridula) on dock plant (Rumex crispus)

Interaction between herbivory and pollution

• N pollutants: decrease C:N ratio >> more palatable• Combined stress of herbivory and pollution may be synergistic

Symbiosis• Close association between individuals of two or more species• Includes parasitism and mutualism• Parasitism: member of one species (parasite) feeds on, but

usually doesn’t kill member of another species (host)• Mutualism: an interaction between individuals of two or

more species in which the growth, growth rate, and/or population size are increased in reciprocal association

Volatile fatty acids: 57 gMicrobial cells: 128 g

Minerals: 43 gRumen dry matter: 343 g

960 g alfalfa Methane, CO2

369 g feces(50 g bacteria; 319 g food residue

• 4.7 L total volume• 20% volume = microorganisms

Rhizobia-legume mutualism

Roots of Red Clover with Adhering Bacteria

Spring Wheat Rhizosphere with Fungi and Bacteria.

Paramecium/Chlorella symbiosis

Cleaner-customer mutualism

Indicator indicator:honeyguideMutualism b/t bird and honeybadger or humans

Deep Sea Pompeii Worm Alvinella pompejana Close-up showing the bacteria-coated filaments that cover the body of this

hydrothermal vent worm. � 2004 Peter Batson/Image Quest Marin

Beltian body

protoeukaryote

Krebs cycle-containing bacterium

promitochondrion

eukaryote

spirochaete

cyanobacteria

chloroplasts

mitochondria

flagellate

dN1

dt=

r1N1(K1 −N1 −a12N2 )K1

Lokta-Volterra

dN1

dt=

r1N1(K1 −N1 + a12N2 )K1

Mutualism??