15.3 “Patterns” of Evolution
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15.3 “Patterns” of Evolution 1. Convergent Evolution 2. Divergent Evolution (Adaptive Radiation) 3. Coevolution
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15.3 “Patterns” of Evolution . 1. Convergent Evolution 2. Divergent Evolution (Adaptive Radiation) 3. Coevolution. Evolution. Chapter 15. 15.3 Shaping Evolutionary Theory. Convergent Evolution. - PowerPoint PPT Presentation
Transcript of 15.3 “Patterns” of Evolution
15.3 “Patterns” of Evolution
1. Convergent Evolution 2. Divergent Evolution
(Adaptive Radiation)
3. Coevolution
Evolution
Unrelated species evolve similar traits even though they live in different parts of the world.
Move towards each other in terms of similarities without any common ancestor
Convergent Evolution
15.3 Shaping Evolutionary Theory
Chapter 15
• Compare the torpedo-shaped body of a fish with the body of a swimming mammal, like a dolphin or a whale. The first mammals were terrestrial and walked on four limbs. As the ancestors of the cetaceans adapted to swimming, their limbs were reduced and their body shape converged on the typical fish shape.
Evolution
Divergent Evolution (Adaptive Radiation)
Can occur in a relatively short time when one speciesgives rise to many different species in response to the creation of new habitat or some other ecological opportunity
15.3 Shaping Evolutionary Theory
Chapter 15
• Divergent evolution is the process of two or more related species from a common ancestor that become more and more dissimilar.
Evolution
Coevolution
The relationship betweentwo species might be so close that the evolution ofone species affects the evolution of the other species.
15.3 Shaping Evolutionary Theory
Chapter 15
• In tropical regions bats visiting flowers to eat nectar. The fur on the bat's face and neck picks up pollen, which the bat transfers to the next flower it visits. Bats that feed at flowers have a slender muzzle and a long tongue with a brushed tip. These adaptations aid the bat in feeding. Flowers that have coevolved with bats are light in color. Therefore, bats, which are active at night, can easily locate them. The flowers also have a fruity odor attractive to bats.
Evolution
Rate of Speciation
Evolution proceeds in small, gradual steps according to a theory called gradualism.
Punctuated equilibrium explains rapid spurts of genetic change causing species to diverge quickly.
15.3 Shaping Evolutionary Theory
Chapter 15
Evolution
15.3 Shaping Evolutionary Theory
Chapter 15
