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Defense mechanisms. Camouflage cryptic coloration. whipporwill. frog. lizard. toad. lizard. Mimicry. Convergent evolution. Batesian mimicry. palatable or harmless species mimics a harmful model. green parrot snake. Hawkmoth larva puffs up to look like poisonous snake. hawkmoth larvae.

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defense mechanisms
Defense mechanisms
  • Camouflage
    • cryptic coloration







Convergent evolution

Batesian mimicry

palatable or harmless species mimics a harmful model

green parrot snake

Hawkmoth larva puffs up to look like poisonous snake

hawkmoth larvae

batesian mimicry
Batesian mimicry

Convergent evolution

Monarch male


Viceroy male


Which is the moth vs. the bee?

Which is the fly vs. the bee?





mullerian mimicry

Mullerian mimicry

Mullerian mimicry

two or more protected species look like each other

cuckoo bee

yellow jacket

- group defense?

- predators may evolve innate avoidance

common warning coloration
Common warning coloration
  • Aposematic species come to resemble each other

black, red, orange & yellowmeans:DON’T EAT ME!

what kind of mimicry
What kind of mimicry?

Coral snake is poisonous

King snake is not

Red on yellow, poison fellow; red on black, safe from attack

coevolution in community
Coevolution in Community
  • Predator-prey relationships
  • Parasite-host relationships
  • Flowers & pollinators

Long term evolutionary adjustments between species

characterizing a community
Characterizing a community
  • Community structure
    • species diversity
      • how many different species
    • composition
      • dominant species
      • most abundant species or highest biomass(total weight)
      • keystone species
      • changes over time
        • succession
species diversity
Species diversity

greater diversity = greater stability

  • Greater biodiversity offers:
    • more food resources
    • more habitats
    • more resilience in face of environmental change
the impact of reduced biodiversity

suburban lawn

“old field”


The impact of reduced biodiversity

compare these communities

  • Irish potato famine
  • 1970 US corn crop failure