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Hiding in plain sight Kate & Michael April 11, 2012. Evolution by natural selection. Natural selection Gradual nonrandom process by which biological traits become more/less common in a population due to differential reproduction. Three components of natural selection. - PowerPoint PPT Presentation
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Hiding in plain sight
Kate & MichaelApril 11, 2012
Evolution by natural selection
• Natural selection– Gradual nonrandom process by which biological
traits become more/less common in a population due to differential reproduction
Three components of natural selection
• Variation – traits are variable within populations• Heredity – traits are heritable across generations• Selection – traits affect fitness (ability to survive and
reproduce)
What is mimicry?
Definitions
• Mimic – a species that experiences increased fitness by resembling another species
• Model – the species being mimicked • Dupe – the species being “duped” by the
mimic
Examples
flower fly
bee
wasp
flower fly
Examples
• Spicebush swallowtail
Examples
“Red on black, friend of Jack. Red on yellow, kill a fellow.”
Examples
• Acoustic mimicry in tiger moths
Examples
• Mimic octopus (Thaumoctopus mimicus)
Mimicry as an evolutionary strategy
• Why is mimicry adaptive?– Would mimics have a different reproductive
success than non-mimics?
• How do you think predator populations might respond over time?
• What happens when mimics outnumber their models?– Density-dependence
• You are a population of predators• Your prey = “Easter egg” species– Green morph– Orange morph (mimic)
• Model = “Toxic” orange egg species– Cause you to become ill (Freeze for 10 seconds!)– You die if you get 3
• What are some possible foraging strategies you could use?