1. Patterns of Evolution
Section 8.3

2. 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

3. 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

4. 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.

5. 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

6. 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

7. 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

8. 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

9. Homework
Answer 8.3 questions #1-5 & 7