hiding in plain sight kate & michael april 11, 2012

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?