- A A pattern in which one interacting species continues to evolve while its close partner species remains largely static, such that fig trees would change over time while their fig wasp pollinators stayed genetically frozen
- B Reciprocal evolutionary changes in two or more species that interact closely; each species acts as selective pressure on the other; example: fig tree and fig wasp, acacia and ants, flower shape and pollinator beak/tongue length
- C Direct competition for resources between two species that occurs without producing any evolutionary change, a relationship where neither competing species ever exerts any selective pressure on the other's traits
- D The seasonal migration patterns of bird species that have little measurable relationship to other species nearby, with little flower shape, pollinator beak length, or other co-adapted trait ever evolving in tandem
Correct answer: B. Reciprocal evolutionary changes in two or more species that interact closely; each species acts as selective pressure on the other; example: fig tree and fig wasp, acacia and ants, flower shape and pollinator beak/tongue length
Explanation: Co-evolution: two species reciprocally drive each other's evolution. Examples: (1) Fig and fig wasp - obligate mutualism; figs can only be pollinated by specific fig wasp; wasp can only reproduce in fig flowers; (2) Yucca plant and yucca moth; (3) Predator-prey arms races (cheetah speed vs gazelle speed); (4) Parasite-host co-evolution; (5) Flower morphology and pollinator co-evolution (Darwin's orchid and predicted moth with 11-inch tongue - found 41 years later).
Concept context
Origin of life, Darwin's theory, natural selection, speciation, and evidence for evolution.