Hot Spots, Cold Spots, and the Geographic Mosaic Theory of Coevolution

2000 ◽  
Vol 156 (2) ◽  
pp. 156-174 ◽  
Author(s):  
Richard Gomulkiewicz ◽  
John N. Thompson ◽  
Robert D. Holt ◽  
Scott L. Nuismer ◽  
Michael E. Hochberg
Keyword(s):  
Hot Spots ◽  
Geographic Mosaic ◽  
Cold Spots ◽  
Geographic Mosaic Theory ◽  
Mosaic Theory

Hot Spots, Cold Spots, and the Geographic Mosaic Theory of Coevolution

2000 ◽  
Vol 156 (2) ◽  
pp. 156
Author(s):  
Gomulkiewicz ◽  
Thompson ◽  
Holt ◽  
Nuismer ◽  
Hochberg
Keyword(s):  
Hot Spots ◽  
Geographic Mosaic ◽  
Cold Spots ◽  
Geographic Mosaic Theory ◽  
Mosaic Theory

scholarly journals Neotyphodium infection and hybridisation as a function of environmental variation

2007 ◽  
Vol 13 ◽  
pp. 215-217
Author(s):  
Cyd Hamilton ◽  
Stan Faeth
Keyword(s):  
Population Level ◽  
Cool Season ◽  
Geographic Mosaic ◽  
Hybrid Superiority ◽  
Geographic Mosaic Theory ◽  
Mosaic Theory ◽  
Grass Hosts ◽  
The Relationship ◽  
Hybrid Forms

Neotyphodium is an asexual, vertically transmitted, obligate fungal endosymbiont infecting cool-season grasses such as Arizona fescue. The relationship between Neotyphodium and several native grass hosts ranges from antagonistic to mutualistic. One theory that may explain how Neotyphodium infection is maintained despite inconsistent mutualistic benefit to the host is the bounded hybrid superiority hypothesis. This hypothesis argues that hybrids are more fit than non-hybrids in response to some environmental stresses. Neotyphodium infects hosts in both hybrid and non-hybrid forms. We tested the possibility of hybrid superiority in depauperate habitats (low soil water and nitrate) by quantifying the types and frequency of host infections (uninfected, hybrid-infected and non-hybrid-infected), and the quality of resources available between three host populations. A second theory, the geographic mosaic theory of coevolution, may also explain different symbiotic outcomes at the population level in response to variation in abiotic and biotic population characters. We provide cursory support for both hypotheses. Keywords: geographic mosaic theory of coevolution, hybrid, Festuca, Neotyphodium, symbiosis, mutualism, bounded hybrid superiority

scholarly journals Local Adaptation of Bacterial Symbionts within a Geographic Mosaic of Antibiotic Coevolution

2019 ◽  
Vol 85 (24) ◽  
Author(s):  
Eric J. Caldera ◽  
Marc G. Chevrette ◽  
Bradon R. McDonald ◽  
Cameron R. Currie
Keyword(s):  
Local Adaptation ◽  
Gene Clusters ◽  
Panama Canal ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Geographic Mosaic ◽  
Content Type ◽  
Antibiotic Inhibition ◽  
Geographic Mosaic Theory ◽  
Mosaic Theory

ABSTRACT The geographic mosaic theory of coevolution (GMC) posits that coevolutionary dynamics go beyond local coevolution and are comprised of the following three components: geographic selection mosaics, coevolutionary hot spots, and trait remixing. It is unclear whether the GMC applies to bacteria, as horizontal gene transfer and cosmopolitan dispersal may violate theoretical assumptions. Here, we test key GMC predictions in an antibiotic-producing bacterial symbiont (genus Pseudonocardia) that protects the crops of neotropical fungus-farming ants (Apterostigma dentigerum) from a specialized pathogen (genus Escovopsis). We found that Pseudonocardia antibiotic inhibition of common Escovopsis pathogens was elevated in A. dentigerum colonies from Panama compared to those from Costa Rica. Furthermore, a Panama Canal Zone population of Pseudonocardia on Barro Colorado Island (BCI) was locally adapted, whereas two neighboring populations were not, consistent with a GMC-predicted selection mosaic and a hot spot of adaptation surrounded by areas of maladaptation. Maladaptation was shaped by incongruent Pseudonocardia-Escovopsis population genetic structure, whereas local adaptation was facilitated by geographic isolation on BCI after the flooding of the Panama Canal. Genomic assessments of antibiotic potential of 29 Pseudonocardia strains identified diverse and unique biosynthetic gene clusters in BCI strains despite low genetic diversity in the core genome. The strength of antibiotic inhibition was not correlated with the presence/absence of individual biosynthetic gene clusters or with parasite location. Rather, biosynthetic gene clusters have undergone selective sweeps, suggesting that the trait remixing dynamics conferring the long-term maintenance of antibiotic potency rely on evolutionary genetic changes within already-present biosynthetic gene clusters and not simply on the horizontal acquisition of novel genetic elements or pathways. IMPORTANCE Recently, coevolutionary theory in macroorganisms has been advanced by the geographic mosaic theory of coevolution (GMC), which considers how geography and local adaptation shape coevolutionary dynamics. Here, we test GMC in an ancient symbiosis in which the ant Apterostigma dentigerum cultivates fungi in an agricultural system analogous to human farming. The cultivars are parasitized by the fungus Escovopsis. The ants maintain symbiotic actinobacteria with antibiotic properties that help combat Escovopsis infection. This antibiotic symbiosis has persisted for tens of millions of years, raising the question of how antibiotic potency is maintained over these time scales. Our study tests the GMC in a bacterial defensive symbiosis and in a multipartite symbiosis framework. Our results show that this multipartite symbiotic system conforms to the GMC and demonstrate that this theory is applicable in both microbes and indirect symbiont-symbiont interactions.

scholarly journals Dos and don'ts of testing the geographic mosaic theory of coevolution

Heredity ◽  
2007 ◽  
Vol 98 (5) ◽  
pp. 249-258 ◽  
Author(s):  
R Gomulkiewicz ◽  
D M Drown ◽  
M F Dybdahl ◽  
W Godsoe ◽  
S L Nuismer ◽  
...  
Keyword(s):  
Geographic Mosaic ◽  
Geographic Mosaic Theory ◽  
Mosaic Theory

scholarly journals Family Practices and Temporality at Breakfast: Hot Spots, Convenience and Care

Sociology ◽  
2021 ◽  
pp. 003803852110155
Author(s):  
Daniela Pirani ◽  
Vicki Harman ◽  
Benedetta Cappellini
Keyword(s):  
Hot Spots ◽  
Hot Spot ◽  
Family Meals ◽  
Personal Integrity ◽  
Structured Interviews ◽  
Time Saving ◽  
Family Time ◽  
Dominant Feature ◽  
Family Practices ◽  
Cold Spots

Drawing on 34 semi-structured interviews, this study investigates the temporality of family practices taking place in the hot spot. It does so by looking at how breakfast is inserted in the economy of family time in Italy. Our data show that breakfast, contrary to other meals, allows the adoption of more individualised and asynchronous practices, hinged on the consumption of convenience products. These time-saving strategies are normalised as part of doing family. Although the existing literature suggests that convenience and care are in opposition, and consumers of convenience products can experience anxiety and a lack of personal integrity, such features were not a dominant feature of our participants’ accounts. These findings suggest that the dichotomies of hot/cold spots and care/convenience are not always experienced in opposition when embedded within family practices. Hence, this study furthers understandings of family meals, temporality and the distinction between hot and cold spots.

scholarly journals Intratumor Heterogeneity in Uveal Melanoma BAP-1 Expression

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1143
Author(s):  
Gustav Stålhammar ◽  
Hans E. Grossniklaus
Keyword(s):  
Gene Expression ◽  
Uveal Melanoma ◽  
Tumor Size ◽  
Hot Spots ◽  
Malignant Tumors ◽  
Intratumor Heterogeneity ◽  
Prognostic Information ◽  
Size Category ◽  
Cold Spots ◽  
Metastatic Risk

Malignant tumors are rarely homogenous on the morphological, genome, transcriptome or proteome level. In this study, we investigate the intratumor heterogeneity of BAP-1 expression in uveal melanoma with digital image analysis of 40 tumors. The proportion of BAP-1 positive cells was measured in full tumor sections, hot spots, cold spots and in scleral margins. The mean difference between hot spots and cold spots was 41 percentage points (pp, SD 29). Tumors with gene expression class 1 (associated with low metastatic risk) and 2 (high metastatic risk) had similar intratumor heterogeneity. Similarly, the level of intratumor heterogeneity was comparable in tumors from patients that later developed metastases as in patients that did not. BAP-1 measured in any tumor region added significant prognostic information to both American Joint Committee on Cancer (AJCC) tumor size category (p ≤ 0.001) and gene expression class (p ≤ 0.04). We conclude that there is substantial intratumor heterogeneity in uveal melanoma BAP-1 expression. However, it is of limited prognostic importance. Regardless of region, analysis of BAP-1 expression adds significant prognostic information beyond tumor size and gene expression class.

scholarly journals Inositol-1,4,5-trisphosphate receptor-mediated Ca2+waves in pyramidal neuron dendrites propagate through hot spots and cold spots

2009 ◽  
Vol 587 (7) ◽  
pp. 1439-1459 ◽  
Author(s):  
John S. Fitzpatrick ◽  
Anna M. Hagenston ◽  
Daniel N. Hertle ◽  
Keith E. Gipson ◽  
Lisa Bertetto-D'Angelo ◽  
...  
Keyword(s):  
Pyramidal Neuron ◽  
Hot Spots ◽  
Inositol 1,4,5 Trisphosphate ◽  
Cold Spots ◽  
Trisphosphate Receptor

scholarly journals A multi-Criteria Wetland Suitability Index for Restoration across Ontario’s Mixedwood Plains

2020 ◽  
Vol 12 (23) ◽  
pp. 9953
Author(s):  
Sally J. Medland ◽  
Richard R. Shaker ◽  
K. Wayne Forsythe ◽  
Brian R. Mackay ◽  
Greg Rybarczyk
Keyword(s):  
Hot Spots ◽  
Relevant Literature ◽  
Wetland Loss ◽  
Soil Drainage ◽  
Suitability Index ◽  
Cold Spots ◽  
Research Questions ◽  
Ecological Landscape ◽  
Hierarchy Process ◽  
Compare And Contrast

Significant wetland loss (~72%; 1.4 million hectares) in the Province of Ontario, Canada, has resulted in damage to important ecosystem services that mitigate the effects of global change. In response, major agencies have set goals to halt this loss and work to restore wetlands to varying degrees of function and area. To aid those agencies, this study was guided by four research questions: (i) Which physical and ecological landscape criteria represent high suitability for wetland reconstruction? (ii) Of common wetland suitability metrics, which are most important? (iii) Can a multi-criteria wetland suitability index (WSI) effectively locate high and low wetland suitability across the Ontario Mixedwood Plains Ecozone? (iv) How do best sites from the WSI compare and contrast to both inventories of presettlement wetlands and current existing wetlands? The WSI was created based on seven criteria, normalized from 0 (low suitability) to 10 (high suitability), and illustrated through a weighted composite raster. Using an Analytical Hierarchy Process (AHP) and importance determined from a scoping review of relevant literature, soil drainage had the greatest meaning and weight within the WSI (48.2%). The Getis-Ord Gi* index charted statistically significant “hot spots” and “cold spots” of wetland suitability. Last, the overlay analysis revealed greater similarity between high suitability sites and presettlement wetlands supporting the severity of historic wetland cannibalization. In sum, this transferable modeling approach to regional wetland restoration provides a prioritization tool for improving ecological connectivity, services, and resilience.

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