The rift setting of eastern Africa preserves exceptional records of mammalian (including hominin) fossils and archeology. The Afar region is host to multiple deposits with sediments ranging in age from>9 Ma to the present (Chorowicz, 2005; Katoh et al., 2016) and plays a major role in our understanding of human origins. The Gona project area contains fossiliferous deposits that span ca. 6.3 to <0.15 Ma (Quade et al., 2008); the duration of this record means that it can make a distinct contribution to understanding the environmental context for human evolution within the Afar and in eastern Africa (Figures 17.1 and 17.2). The primary units at Gona include the late Miocene Adu-Asa Formation, which contains fossils of Ardipithecus kaddaba; the early Pliocene Sagantole Formation with fossils of Ardipithecus ramidus; the mid- to late-Pliocene Hadar Formation; and the Busidima Formation (ca. 2.7 Ma to <0.15 Ma), which contains a record of the earliest Oldowan stone tools, fossils of Homo erectus, and Acheulean artifacts (Figure 17.2).

The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.

The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.

The F factor is often associated with Escherichia coli and appears to have been adapted by the bacterial host to act as an agent of genetic exchange and evolution. F encodes a type IV secretion system (T4SS) that enables bacterial conjugation, the transfer of DNA from a donor F+ to a recipient F− cell. The delivery of DNA containing either host or foreign genes has important consequences for the bacterium, allowing it to enlarge or modify its genetic content and rapidly adapt to an environmental niche. Unlike other plasmids, the conjugative functions of F and F-like plasmids appear to be controlled by a complex regulatory network that involves many host proteins resulting in a symbiotic relation between F and its host. This chapter outlines the predicted and known functions for all the genes on the F plasmid and its close relatives, and describes our current knowledge about the regulation of F conjugation.

BRIEF HISTORY OF THE F PLASMID

The discovery of horizontal gene transfer between bacteria can be attributed to the work of Lederberg and Tatum (1946), who observed that different strains of E. coli K-12 could be genetically and phenotypically altered when mixed together. A series of experiments led to the conclusion that direct contact between bacteria was required in order for genetic material to be transferred between the cells (Davis, 1950). This transfer was found to occur in one direction, from donor to recipient cells, by a mechanism contained within the donor cells (Hayes, 1952).