This session explores the intersection of geology and ecology in the 19th and 20th centuries. The questions we pursue are: How did scientists use information from one time-period or region to infer features of another, distant, time period or region? How did they determine which questions were worth pursuing or prioritizing? Our answers are unified by an emphasis on how ecological considerations delimited what could be learned about a particular time period or region using comparisons with another time or place. Historians have discussed the fit between organisms and their environment, and have focused on the geographical distribution of species. Yet, the manner in which ecological considerations so consistently modified the practices and motivations of scientists has been under-discussed. By collecting three cases in which this occurred, we hope to motivate further research into how ecological frameworks determined the validity of certain inferences. Examples discussed include (a) testing the relatedness of animal forms to their environments to aid with reconstructions of past habitats from fossil data, (b) how Charles Darwin saw the complexity of ecological relations in coral reefs as delimiting predictions regarding their formation in unexplored areas, and (c) how disanalogies between the deep past and the present required paleoecologists to modify how knowledge of the past could be useful for predicting the future. In all cases, scientists were concerned not merely with using known information to predict unknown features (past, present, or future), but with the construction of frameworks which discerned when such inferences were reasonable.
