Islands in the sky

Islands have many biological oddities because the organisms there are isolated from those on the mainland and this can have many consequences. Unless you are a biologist you probably don't think about mountains tops and the species living there as islands yet they are. One question of interest is determining how much gene flow exists between populations on different islands, and one of my colleagues, Andrea Kramer, has been examining this by looking at bumblebee (see image) and hummingbird pollinated penstemons, and she found that the bee-pollinated species were more distinct mountain to mountain. This means as you may suspect that birds are better at moving genes greater distances than bees. Genetic diversity on mountain top islands is a particularly critical thing to study because a warming climate pushes alpine species higher, and if the mountain isn't tall enough, that population become extinct, and the islands getter smaller, fewer, and farther apart. Islands in the sky may be one of the places where climate change results in the loss of a lot biological diversity especially those that are highest, the inhabitants of alpine tundra. As a change of pace, alpine tundra will be featured in a few upcoming blogs.