Behavioral interactions between animals involve communication

-Communication can take place between members of the same species (conspecifics) or different species (heterospecifics)

Signal Modalities

-Animals communicate using signals such as a urine trail

Animals communicate for many reasons:

  • Sexual advertisement and mate attraction
  • Parental care (begging,recognition)
  • Environmental information (predator alarms, food location
  • Territory defense, conflict resolution
  • Social integration (contact calls)
  • Predator defense (warning coloration)

Selection acts on per-existing traits

  • Female (and male) whistling moths detect the ultrasonic signals generated by male moths

Sensory Exploitation

  • Communication signals originate in actions that activate per-existing sensory ability of receivers

Example: In African Cichlid fish- Male with bright orange spots on the anal fin, a female may try to pick up what appear to be eggs on the fin

Adaptation- Doesn’t have to be perfect, the benefits of the trait outweighs the cost of the trait

Maladaptation- Doing something that decreases the animals fitness

Deception in Photuris female fireflies- Male photinus flies flash to attract females of their species, but sometimes a female of another species, Photuris responds to his signal

  1. Novel Environmental Theory
  2. Net Benefit Theory

-An adaptation does not have to be perfect

The Elbow Orchid has flowers with lip petals that resemble a female wasp

Male thynnine wasps are attracted by the order and appearance of the female decoys


-Predators can take advantage of voice calls/mate calls and use it to find them

-Evolution can change the way the animals call either with frequency or volume – influences the evolution of bird calls

Other maladaptations:

  • Pleiotrophy: one gene causes multiple phenotypic effects (Net benefit theory )
  • Genetic Drift- Random events that lead to changes, maladaptations in smaller populations
  • Gene Flow- Movement of individuals, and/or the genetic material they carry, from one population to another

Screen Shot 2018-02-22 at 12.17.51 PM.png

“Gene Flow” by Wikimedia Commons under CC by 2.0

Agelenopsis aperta


Desert Grassland population: Harsh environment, low predators, More aggressive

Riparian population :more favorable environment, more cautious

Arizona: More gene flow

The riparian population is much more aggressive and less cautious then predicted

Gene flow from desert pop to riparian responsible







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