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Daniel Livingstone and Paul Colinvaux (Fig. 1a and b) were intellectual pioneers who helped to shape modern tropical paleoecology. Linked in life by bonds of friendship, they shared a common philosophy of challenging conventional wisdom and exploring remote areas to seek answers. Dan and Paul both had common starts to their research careers with PhD’s focused on the arctic (Livingstone, 1955a) and strong early influence and guidance from Prof. Ed Deevey at Yale; he was Dan’s PhD advisor and Paul’s postdoctoral mentor. At Deevey’s urging, bothmen turned their attention to the tropics. In his 2007 book, Paul summed up their division of labor: “Dan was already doing Africa; I chose the Amazon” (Colinvaux, 2007, p. 11). Both Livingstone and Colinvaux were first and foremost ecologists, who used paleoecology to answer ecological questions. Dan and Paul both died in the spring of 2016, and this special issue is a tribute to the inspiring enthusiasm and energy they brought to research and education. Members of every generation can argue that they live in interesting times, but for budding ecologists, the late 1950s and 1960s, when Dan and Paul were in graduate school, were especially formative. Geology, climatology, and ecology were being revolutionized by new ideas and technologies. In this period, plate tectonics went from being a fringe idea to being widely accepted (Dietz, 1961). Gone was the insistence that organisms must have dispersed across oceans or migrated across lost land bridges. Vicariance was now a far more plausible means of speciation than previously thought (Wilson, 1963). A welter of new information based on isotopic chemistry was reshaping paleoecology and paleoclimatology. Radiocarbon dating, first developed by Libby (1960), allowed fist-sized sections of organic-rich material to be dated. This development transformed the study of lake sedimentary sequences, allowing real chronologies to be developed and to set aside assumptions that similar looking vegetation changes were coeval. Emiliani’s (1955) isotopic record of marine sediment provided the first strong record of the changes of global temperature within the Quaternary. That Quaternary ice ages were relatively slow to develop, stair-stepping down toward a maximum cooling, before rapidly bouncing out into interglacial conditions, was of tremendous significance to anyone contemplating species migrations. For decades ecologists had been debating whether communities were relatively fixed or fluid in composition (Clements, 1916; Gleason, 1926), and a pivotal moment was reached in that discussion in the early 1960s. Plant phytosociologists whose views had held sway since the 1920s tended to see the world as tightly coevolved communities that would migrate as a unit. When viewed through time, vegetation zones of temperate forest, boreal forest, and tundra were depicted being driven north and south (Braun, 1955) or upand downslope (Gonzalez et al., 1966). Whittaker’s demonstration that species did not turn over in unison along ecological gradients in the Smoky and Siskyou Mountains (Whittaker, 1956, 1960) signaled a paradigm shift in how ecologists viewed species occurrence in communities. As paleoecologists started to champion the individuality of species’ responses to past climate change, Livingstone in Africa and Colinvaux in South America became advocates of this new view. Livingstone and Colinvaux combined developments in geology, climatology, and ecology and used these advances to tackle great questions of species distributions, endemicity, and richness. When they started their careers in the 1960s, fossil pollen records existed for Europe and much of North America, but areas of more extreme climate were virtually unknown. At the time of their deaths, in 2016, hundreds of records of past ecological change existed from the tropics (Flantua et al., 2015). Today, the pursuit of the origins of tropical diversity goes on, but this is now guided by a SPECIAL ISSUE