Patterns of Evolution Section 8.3

Patterns of Evolution Learning Goal: To explore the patterns of evolution. Success Criteria: I know I am succeeding when I can… discuss the characteristics of adaptive radiation explain divergent evolution and give relevant examples from modern ecosystems explain the difference between convergent evolution and coevolution

Adaptive Radiation adaptive radiation: occurs when a single species evolves into a number of distinct but closely related species each new species fills a different ecological niche process usually occurs when a variety of new resources become available ex. 13 species of Darwin’s finches that live in the Galapagos Islands evolved from a single species

Divergent Evolution divergent evolution: the evolution of a group into many different species, each with their own specializations occurs when species evolve in order to fill ecological roles (minimizes competition between species and increases biodiversity) ex. Ontario has over 20 species of closely related rodents, including mice and voles. Mice prefer small seeds and insects and usually nest in trees, while voles nest on the ground and eat roots and buds.

Convergent Evolution convergent evolution: the evolution of similar traits in distantly related species occurs when two different species, or taxa, evolve to occupy similar ecological niches ex. sharks and dolphins are very distantly related species but both have evolved very similar body shapes well suited for their high-speed carnivorous behaviour

Coevolution coevolution: one species evolves in response to the evolution of another species (evolution is linked) ex. certain plants have evolved hard protective shells to protect their seeds, while some seed-eating mammals have evolved powerful jaws and teeth for chewing through hard shells most pronounced in symbiotic relationships

Coevolution Cont’d… ex. the Madagascar long-spurred orchid has nectar at the end of a 30 cm long spur and its only pollinator, a hawk moth, has a tongue the same length

Patterns of Evolution Learning Goal: To explore the patterns of evolution. Success Criteria: I know I am succeeding when I can… discuss the characteristics of adaptive radiation explain divergent evolution and give relevant examples from modern ecosystems explain the difference between convergent evolution and coevolution

Homework Answer 8.3 questions #1-5 & 7