Neo-Assyrian concepts of fortification

The major cities of the Neo-Assyrian Empire were not only home to impressive palaces and temples, but they were also equipped with strong fortifications. The city walls were not only meant to keep out potential enemies, but by demonstrating Assyria’s power to any approaching person, they served an ideological purpose, as well. However, military efficiency was just as crucial, since, over its entire history, the empire repeatedly faced internal and external threats and could not have afforded to lose any of its urban centers which were essential to maintaining control over the various provinces or geographic regions associated with them. The study of Neo-Assyrian fortifications relies on evidence provided by archaeological excavations, the study of Assyrian reliefs and information from cuneiform texts. Even though these sources help us reconstruct the appearance of the town defenses, the question of why the individual fortification systems were built in a specific way cannot be addressed by these means alone. Remote sensing offers an opportunity to view the course and placement of the city walls within their topographical context. Furthermore, geographical information systems (GIS) offer a tool to illustrate the distribution of the strongly fortified Assyrian towns, thereby allowing us to recognize patterns and functions of regional fortification systems during the Neo-Assyrian period.

Rapid divergence in physiological and life-history traits between northern and southern populations of the British introduced neo-species, Senecio squalidus

Alien plants provide a unique opportunity to study evolution in novel environments, but relatively little is known about the extent to which they become locally adapted to different environments across their new range. Here, we compare northern and southern populations of the introduced species Senecio squalidus in Britain; S. squalidus has been in southern Britain for approximately 200 years and reached Scotland only about 50 years ago. We conducted common garden experiments at sites in the north and south of the species’ range in Britain. We also conducted glasshouse and growth chamber experiments to test the hypothesis that southern genotypes flower later, are more drought-tolerant, germinate and establish better at warmer temperatures, and are less sensitive to cold stress than their more northern counterparts. Results from the common garden experiments are largely consistent with the hypothesis of rapid adaptive divergence of populations of the species within the introduced range, with genotypes typically showing a home-site advantage. Results from the glasshouse and growth chamber experiments demonstrate adaptive divergence in ability to tolerate drought stress and high temperatures, as well as in phenology. In particular, southern genotypes were more tolerant of dry conditions and high temperatures and they flowered later than northern genotypes. Our results show that rapid local adaptation can occur in alien species, and they have implications for our understanding of the ecological genetics of range expansion of introduced weeds.