BIO 126 Lecture Notes - Lecture 19: Great American Interchange, Wallace Line, Convergent Evolution
10 Mar 2016
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Document Summary
Why evolution is true: chapter 4, class notes. Endemic species: they are found nowhere else in the world except for the place they inhabit. Speciation: process by which each common ancestor gives rise to many different descendants. Continental biogeography: pattern and distribution of organisms on continents. Continental islands: once connected to a continent, but then separated by rising sea levels or the shifting of continental plates: continental drift. Convergent evolution: species that involved independently will begin to form similar traits, due to environmental pressures. Oceanic islands: never connected to a continent; arose from the sea floor: ex: galapagos islands, hawaiian islands. Trees are rare because seeds are too heavy for traveling. Marsupials are more closely related to one another than animals that have physical similarities: result of convergent evolution, have internal organs and traits that separate them from other organisms. Ex: have pouches to carry young, don"t have placentas, double uterus (females), 4 pairs of molars.
