11.5 Speciation Through Isolation Updates: Homework: –Quizzes continue Thursday: 10.3, 11.1, 11.2 –Sickle cell questions due Thursday –Read 11.3 SQ3R theme: founder effect due Friday AAP: Mondays, Tuesdays, Thursdays Quiz makeups: must be done today!

11.5 Speciation Through Isolation LEQ: How does a species adapt to its environment? Do Now: wordsplash Use three or more of the following terms in a sentence –Natural selection (any type), allele/trait frequency, fitness, variation, adaptive trait, Minimum of three sentences Key Terms: adaptive radiation

11.5 Speciation Through Isolation Natural Selection Review: In order to describe if natural selection is taking place: Describe the variation observed; how common is each trait? What is the selection pressure(s) this population faces? –Negative, positive? What are they? What is the underlying genetic basis for variation? –Mutation? Dominant, recessive, etc. How are the population’s traits and gene pool changing over time? –Which traits are increasing/decreasing…what’s “fit”?

11.5 Speciation Through Isolation Updates: Sickle cell questions due Homework: –Quizzes done for week, resume Tuesday –Read 11.3 SQ3R theme: founder effect due Friday AAP: Mondays, Tuesdays, Thursdays

11.5 Speciation Through Isolation LEQ: How does a species adapt to its environment? Do Now: Collins Writing Study the supplementary figure showing offspring data: –Write a minimum of 3 lines describing important things you noticed that indicate natural selection is occurring. Key terms: adaptive radiation

11.5 Speciation Through Isolation Pair-share: look at this graph. What do you see? –What does it mean?

11.5 Speciation Through Isolation Read the figure caption. Do you know anything new?

11.5 Speciation Through Isolation Pair-share: compare the offspring from 1976 to offspring from What do you see? What does it mean? Beak Depth (mm) Number of Birds Caption: Distributions of beak depths of fully grown offspring hatched in 1976 and 1978 respectively.

11.5 Speciation Through Isolation Adaptive traits: beak development explained How are beaks able to change in a single generation? –Existing variation in beak gene expression –Amount, timing

11.5 Speciation Through Isolation High level of BMP4 promotes a wide, deep beak. Low levels of calmodulin promotes a short beak. Speculate: how is variation in gene expression related to food preference?

11.5 Speciation Through Isolation

Biogeography can reveal patterns island finch species closely resemble a mainland species –DNA: more closely related to each other –Geography isolated populations

11.5 Speciation Through Isolation Heterometry: variation in structure, variation in function

11.5 Speciation Through Isolation Is variation in food related to variation in adaptive traits?

11.5 Speciation Through Isolation

Closure: natural selection and adaptation Why are so many different finch species occurring/co- occurring on the Galapagos islands? Adaptive radiation - populations diversify rapidly due to: –Opportunities to move into new habitats –Changes in selection pressures (drought, rain) –Variation in traits allows for the flexibility to adapt Result: populations change as they adapt, specialize

11.5 Speciation Through Isolation How did natural selection affect trait/allele frequencies of finches during the drought/rainfall on Daphne Major? What anatomical and genetic evidence supports the science that finches can change over time? Why is variation in beaks necessary in order for species to adapt to their environments?

11.5 Speciation Through Isolation