What darwin saw: a geographical perspective on biodiversity and. Adaptation: contrasts between tropical & temperate ecosystems, the role of biotic and abiotic interactions in tropical and temperate ecosystems, respectively, gal pagos islands as evolutionary laboratories, australia"s isolation and its unique biota. Slide 1: charles darwin"s voyage on the h. m. s beagle: age 22, ship"s naturalist, most time spent in south america, observations of fossils, geographical distribution of plants and animals, and ora and fauna of oceanic islands, ex. Oak woodland in england characterized by low species diversity. Pest and disease pressures on plants more intense. Wednesday, september 20, 2017: dense canopies and long-distances between trees make wind a poor agent of pollen dispersal; animals are more effective pollinators, bees, butter ies, moths, birds and bats pollinate most tropical trees; most temperate tree wind pollinated. Slide 4: euglossine bees as long-distance pollinators of tropical plants (science.