Presentation on theme: "Bellwork Imagine that you are traveling in Madagascar when you find the plant to the left. You see that the plant has an unusually large spur containing."— Presentation transcript:
1 BellworkImagine that you are traveling in Madagascar when you find the plant to the left. You see that the plant has anunusually large spur containing nectar in its tip. You remember learning in science class that some moths feed on nectar. Draw a picture of what you think a moth may look like that feeds on this plant.SpurHow might natural selection bring about the evolution of this orchid and the moth?
6 Co-evolutionSometimes organisms that are closely connected to one another by ecological interactions evolve together.An evolutionary change in one organism may also be followed by a corresponding change in another organism.The process by which two species evolve in response to changes in each other over time is called coevolution.
7 Coevolution Species A evolves an adaptation in response to species B Species B evolves in response to the adaptation of species A
8 Coevolution can occur with species that help or compete with each other
10 Mimicry is another example of coevolution Mimicry occurs when one organism evolves to look like the other in order to benefit itself. The mimic benefits from the situation while the organism it mimics in unaffected.Example: Orchid flowersthat mimic female waspsDiscussion Questions:How does the flower benefit from looking like the female wasp? The flower benefits because the male wasp lands on the flower expecting to mate and is covered in pollen. It then flies to another flower that looks like a female wasp and pollinates the plant.Predict what would happen to the flower if the appearance of the female wasp began to change?If the female wasp began to change in appearance so would the flower. Flowers that looked more like the changing female wasp would be pollinated, while those that did not look like the female wouldn’t. This would cause the flower population to look more like the female wasp.
12 Convergent EvolutionConvergent evolution describes evolution toward similar traits in unrelated species.When two species are similar in a particular characteristic, it’s only convergent evolution if their ancestors were not similar
14 Divergent evolution describes evolution toward different traits in closely related species. Divergent evolution can lead to speciation.kit foxred foxancestor
15 Changes in the frequency of a gene in the gene pool initially leads to microevolution. Microevolution refers to a small change in a population over a short amount of time. Many small changes eventually lead to macroevolution. Macroevolution refers to the sum total of many changes that transform organisms over a long period of time. Macroevolution leads to speciation or the creation of a new species. When an evolving population can no longer interbreed with the original population, a new species is formed.
18 So what about the fossil record… Things to Consider:Stasis - The organisms in the fossil record looks the same from when they appear to when they disappear;Sudden appearance - When a species does not arise by gradually changing steadily from its ancestors; it appears all at once and fully formed.Sequential nature – Based on the layers of rock, we sequence organisms in the fossil record.What might cause stasis or sudden appearance?
19 WHICH PATTERN IS IT? divergent evolution WHICH PATTERN IS IT?coevolution convergent evolution divergent evolutionThe Galápagos finches evolved through naturalselection from a common ancestor into a widevariety of different looking species with differentkinds of beaksdivergent evolution
20 coevolution WHICH PATTERN IS IT? coevolution convergent evolution divergent evolutionHummingbirds have a beak just the right lengthto reach the nectar in a cardinal flower and asthey feed their foreheads bump into the pollen structure. Cardinal flowers are red whichhummingbirds can see, but bees can’t, and theirpollen structure is at just the right height forthe hummingbird to pick up pollen as it feeds.coevolution
21 Convergent evolution WHICH PATTERN IS IT? coevolution convergent evolution divergent evolutionWhales, sharks, and penguins all have streamlinedbodies and fins/flipper for moving in watereven though they belong in different animal groups(mammals, fish, and birds)Convergent evolution
22 Adaptive radiation OR divergent evolution WHICH PATTERN IS IT?coevolution convergent evolution divergent evolutionBeaverNORTH AMERICAMuskratCapybaraSOUTH AMERICACoypuBeaver and MuskratBeaver in North America and capybara in South America are closely related species living in very differentenvironments that have evolved to look different over time.Adaptive radiation OR divergent evolutionBIOLOGY by Miller and Levine Pearson Publishing
23 divergent evolution WHICH PATTERN IS IT? coevolution convergent evolution divergent evolutionThe tortoises on the Galapagos islands share a common ancestor, but over time they have becomeadapted for obtaining food in different habitatson different islands by having different neck lengthsdivergent evolution