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Modern ecological studies indicate that the degree of openness in African vegetation cover is determined, in part, by the presence of herbivores and fire as consumers of vegetation. Where herbivores are the dominant consumer of vegetation the resultant open state is described as a ‘brown’world. Where fire is the dominant consumer of vegetation the resultant open state is described as a ‘black’ world. While if neither consumer is dominant then a more closed canopy states arises that is described as a ‘green’world. Here we use palaeoecological data obtained from Lake Bosumtwi (Ghana) to characterize green, brown, and black worlds during two short sections of around 1000 years each, deposited around 200,000 and 100,000 years ago(Middle and Late Pleistocene).We characterize the vegetation cover using pollen and phytoliths, herbivory using Sporormiella and fire using micro-charcoal. We find that during c. 1000 years of the Middle Pleistocene fire was the major consumer of vegetation, while during c. 1000 years in the Late Pleistocene herbivores were relatively more important consumers of vegetation. We therefore suggest that the Middle Pleistocene section represents a black world, while in the Late Pleistocene section we capture a combination of green, brown and black worlds. The duration of these states seems to range from centuries to millennia and transitions are observed to occur in both an abrupt and a stepwise fashion. These preliminary data demonstrate how palaeoecological information can be used to gain insights into past landscape scale processes over thousands of years. Further work is required to test the robustness of these findings and to provide a higher temporal resolution to aid the link with modern ecological studies.

In this article, we describe experiences with dialogue evenings within a research collaboration on long-term care and dementia in the Netherlands. What started as a conventional process of ‘reporting back’ to interlocutors transformed over the course of two years into learning and knowing together. We argue that learning took place in three different articulations. First, participants learnt to expand their notion of knowledge. Second, they learnt to relate differently to each other and, therewith, to dementia. And third, participants learnt how to generate knowledge with each other. We further argue that these processes did not happen continuously, but in moments. We suggest that a framework of collaborative moments can be helpful for research projects that are not set up collaboratively from the start. Furthermore, we point to the work required to facilitate these moments.