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 fitness by resembling another species
• Model – the species being mimicked • Dupe – the species being “duped” by the
mimic
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