Climate change is today's news, but it isn't a new phenomenon. Centuries-long cycles of heating and cooling are well documented for Europe and the North Atlantic. These variations in climate, ...including the Medieval Warm Period (MWP), AD 900 to 1300, and the early centuries of the Little Ice Age (LIA), AD 1300 to 1600, had a substantial impact on the cultural history of Europe. In this pathfinding volume, William C. Foster marshals extensive evidence that the heating and cooling of the MWP and LIA also occurred in North America and significantly affected the cultural history of Native peoples of the American Southwest, Southern Plains, and Southeast.
Correlating climate change data with studies of archaeological sites across the Southwest, Southern Plains, and Southeast, Foster presents the first comprehensive overview of how Native American societies responded to climate variations over seven centuries. He describes how, as in Europe, the MWP ushered in a cultural renaissance, during which population levels surged and Native peoples substantially intensified agriculture, constructed monumental architecture, and produced sophisticated works of art. Foster follows the rise of three dominant cultural centers-Chaco Canyon in New Mexico, Cahokia on the middle Mississippi River, and Casas Grandes in northwestern Chihuahua, Mexico-that reached population levels comparable to those of London and Paris. Then he shows how the LIA reversed the gains of the MWP as population levels and agricultural production sharply declined; Chaco Canyon, Cahokia, and Casas Grandes collapsed; and dozens of smaller villages also collapsed or became fortresses.
The late Permian mass extinction event was the largest biotic crisis of the Phanerozoic and has the longest recovery interval of any extinction event. It has been hypothesised that subsequent carbon ...isotope perturbations during the Early Triassic are associated with biotic crises that impeded benthic recovery. We test this hypothesis by undertaking the highest-resolution study yet made of the rock and fossil records of the entire Werfen Formation, Italy. Here, we show that elevated extinction rates were recorded not only in the Dienerian, as previously recognised, but also around the Smithian/Spathian boundary. Functional richness increases across the Smithian/Spathian boundary associated with elevated origination rates in the lower Spathian. The taxonomic and functional composition of benthic faunas only recorded two significant changes: (1) reduced heterogeneity in the Dienerian, and (2) and a faunal turnover across the Smithian/Spathian boundary. The elevated extinctions and compositional shifts in the Dienerian and across the Smithian/Spathian boundary are associated with a negative and positive isotope excursion, respectively, which supports the hypothesis that subsequent biotic crises are associated with carbon isotope shifts. The Spathian fauna represents a more advanced ecological state, not recognised in the previous members of the Werfen Formation, with increased habitat differentiation, a shift in the dominant modes of life, appearance of stenohaline taxa and the occupation of the erect and infaunal tiers. In addition to subsequent biotic crises delaying the recovery, therefore, persistent environmental stress limited the ecological complexity of benthic recovery prior to the Spathian.
Authenticity is increasingly seen as a source of competitive advantage in many industries. Accordingly, authenticity work, the organizational efforts to develop and sustain believable authenticity ...claims, has emerged as an important organizational practice. We examined the interplay of materiality and narratives underpinning producers' authenticity work in the context of incumbent and micro-distilleries operating in the Canadian whisky industry. We found that producers' material endowments, especially central product features, anchored which authenticity claims they could credibly narrate. Other material endowments, such as key people and architectural design, were used to reinforce the integrity of authenticity claims. Our study extends our understanding of authenticity as a valued organizational resource. First, we identify two mechanisms, anchoring and reinforcement, through which materiality both constrains and facilitates organizations' authenticity narratives. Second, our research brings to the fore how audience members' experiential closeness to producers colors their perceptions of authenticity, and we show how material artifacts can enhance such closeness. Third, our findings highlight the competitive value of authenticity by unpacking how producers' material endowments may constitute a resource or a liability.
Living in nests is an almost universal feature of eusocial animals. In some aphids, however, sterile soldier castes have evolved in open colonies without a nest. To clarify the factors promoting the ...evolution of eusociality in these colonies, we used newly developed microsatellite markers to compare the kin structure of the open colonies of two aphid species on bamboo: the non-eusocial colonies of
Astegopteryx bambucifoliae
and the eusocial colonies of
Pseudoregma alexanderi
on
Dendrocalamus latiflorus
.
Our samples, from over 1000 hectares, contained 99 clones of
A. bambucifoliae
and 19 of
P. alexanderi
. Clonal mixing occurred in both species: average pairwise relatedness within a colony was 0.54 in
A. bambucifoliae
and 0.71 in
P. alexanderi
. Each clone of
A. bambucifoliae
occurred in a unique location, whereas those of
P. alexanderi
occurred in multiple locations and more than 90% of individuals came from just four clones. There was significant genetic variation among different colonies in the same clump (stem-cluster) in
A. bambucifoliae
but not in
P. alexanderi
, indicating that
P. alexanderi
colonies in a single clump are genetically homogenised, functioning as a large colony. In
P. alexanderi
, the proportion of sterile soldiers to normal first-instar nymphs was significantly different across the four clones.
Our results indicate that the lack of input of migrants from the primary host and feeding on a large, stable host plant are important ecological factors that might favour the evolution of eusociality, enabling the production of genetically homogenised, large, and long-lived colonies. After eusociality evolves on the secondary host, the optimal strategy of soldier production might vary between different clones.
Significance statement
Nest living has often been considered to be a necessary condition for the evolution of eusociality. In a small number of aphid species, however, sterile soldier castes have evolved in open colonies without a nest. To understand why these aphids are unique, we examined the kin structure and genetic relatedness of individuals within eusocial and non-eusocial open colonies of two aphid species on bamboo. We found that clonal mixing occurred in both species, but the eusocial colonies are more genetically homogenised, functioning as a large colony. Our results suggest that ecological conditions that promote genetically homogenised, large and long-lived colonies are important for the evolution of eusociality in these aphids. We propose that the open colonies of social aphids provide an ideal model system in which to study the evolution of altruism.
One of the important cultural responses to political and sociohistorical events in Latin America is a resurgence of urban photography, which typically blends high art and social documentary. But ...unlike other forms of cultural production in Latin America, photography has received relatively little sustained critical analysis. This pioneering book offers one of the first in-depth investigations of the complex and extensive history of gendered perspectives in Latin American photography through studies of works from Argentina, Mexico, and Guatemala.David William Foster examines the work of photographers ranging from the internationally acclaimed artists Graciela Iturbide, Pedro Meyer, and Marcos López to significant photographers whose work is largely unknown to English-speaking audiences. He grounds his essays in four interlocking areas of research: the experience of human life in urban environments, the feminist matrix and gendered cultural production, Jewish cultural production, and the ideological principles of cultural works and the connections between the works and the sociopolitical and historical contexts in which they were created. Foster reveals how gender-marked photography has contributed to the discourse surrounding the project of redemocratization in Argentina and Guatemala, as well as how it has illuminated human rights abuses in both countries. He also traces photography's contributions to the evolution away from the masculinist-dominated post–1910 Revolution ideology in Mexico. This research convincingly demonstrates that Latin American photography merits the high level of respect that is routinely accorded to more canonical forms of cultural production.
Organisms can often benefit by distinguishing between different classes of individuals. An example is kin recognition, whereby individuals preferentially associate with or aid genetic relatives that ...bear matching recognition cues but reject others. Despite its potential benefits, however, kin recognition using genetically based cues is often weak or absent 1–4. A general explanation, termed “Crozier’s effect,” is that when individuals interact randomly, rarer cue alleles less often match cues of other individuals, and so are involved predominantly in “reject”-type interactions. If such interactions are more costly, positive frequency-dependent selection will erode the cue diversity upon which discrimination depends 4, 5. Although widely cited 1, 2, 4, 6–9, this idea lacks rigorous testing in the field. Here, we show how Crozier’s effect applies to interactions between hosts and conspecific parasites, and measure it using field data. In the wasp we studied, conspecific parasitism fits a key assumption of Crozier’s model: the same females act as both hosts and parasites. By exchanging offspring between nests experimentally, we find no evidence that females respond to genetically based cues associated with foreign offspring. Through measuring costs and benefits, however, we demonstrate a strong Crozier effect: because more parental investment is wasted when foreign offspring are rejected, interactions involving rejection have substantially lower payoffs than interactions involving acceptance. Costly rejection can thus eliminate cue diversity by causing selection against rare cue alleles, consistent with the absence of genetically based recognition that we observe. Females instead appear to rely on non-genetic cues that enable them to detect less than half of parasitic offspring.
•Digger wasps parasitize parental care by replacing eggs in each others’ nests•Hosts sometimes reject foreign eggs, but not using intrinsic genetic cues•Rejection involves more wastage of parental investment than acceptance•Costly rejection causes selection against cue diversity required for discrimination
Despite its benefits, kin recognition is often absent in nature. Field et al. show that digger wasps often fail to reject foreign conspecific offspring from their nests. Rejection involves more wastage of parental investment than acceptance. Costly rejection leads to selection against allelic diversity required for discrimination using genetic cues.
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