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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.
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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 • Variation – traits are variable within populations • Heredity – traits are heritable across generations • Selection – traits affect fitness (ability to survive and reproduce)
Definitions • Mimic – a species that experiences increased fitnessby 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 (Thaumoctopusmimicus)
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?