Reference no: EM132547692

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1. Pikas originated in Asia. Which abiotic factor plays the largest role in determining where pikas can live? How did the American pika arrive in North America? How has their geographic range been altered since the last ice age? How will their range be influenced by global climate change? What are the genetic diversity implications resulting from these range changes?

2. On the Tibetan Plateau, solar energy is harnessed by grasses via photosynthesis, pikas feed on the grass, and brown bears feed on pikas. Explain in general why there is less and less energy available at each stage of this process (i.e. why there is less energy available to pikas than grass, less to bears than pikas, etc.). Describe at least two specific reasons per trophic level - grass, pika, and bear - for why less energy is available to it (that's six reasons in total).