scholarly journals Linking host plants to damage types in the fossil record of insect herbivory

2021 ◽  
Author(s):  
Sandra R Schachat ◽  
Jonathan L. Payne ◽  
C. Kevin Boyce
Keyword(s):  
Beta Diversity ◽  
Fossil Record ◽  
Host Plants ◽  
Insect Herbivory ◽  
Multiple Comparisons ◽  
Bipartite Network ◽  
Insect Damage ◽  
Ecological Literature ◽  
Network Metrics ◽  
Damage Types

Studies of insect herbivory on fossilized leaves tend to focus on a few, relatively simple metrics that are agnostic to the distribution of insect damage types among host plants. More complex metrics that link particular damage types to particular host plants have the potential to address additional ecological questions, but such metrics can be biased by sampling incompleteness due to the difficulty of distinguishing the true absence of a particular interaction from the failure to detect it---a challenge that has been raised in the ecological literature. We evaluate a range of methods for characterizing the relationships between damage types and host plants by performing resampling and subsampling exercises on a variety of datasets. We found that the components of beta diversity provide a more valid, reliable, and interpretable method for comparing component communities than do bipartite network metrics. We found the rarefaction of interactions to be a valid, reliable, and interpretable method for comparing compound communities. Both of these methods avoid the potential pitfalls of multiple comparisons. Lastly, we found that the host specificity of individual damage types is challenging to assess. Whereas some previously used methods are sufficiently biased by sampling incompleteness to be inappropriate for fossil herbivory data, alternatives exist that are perfectly suitable for fossil datasets with sufficient sample coverage.

scholarly journals Generating and testing hypotheses about the fossil record of insect herbivory with a theoretical ecospace

2021 ◽  
Author(s):  
Sandra R Schachat ◽  
Jonathan L Payne ◽  
C Kevin Boyce ◽  
Conrad C Labandeira
Keyword(s):  
Surface Area ◽  
Fossil Record ◽  
Leaf Surface ◽  
Insect Herbivory ◽  
Fossil Flora ◽  
Insect Damage ◽  
Leaf Surface Area ◽  
Number Of Leaves ◽  
Damage Type ◽  
Damage Types

A typical fossil flora examined for insect herbivory contains a few hundred leaves and a dozen or two insect damage types. Paleontologists employ a wide variety of metrics to assess differences in herbivory among assemblages: damage type diversity, intensity (the proportion of leaves, or of leaf surface area, with insect damage), the evenness of diversity, and comparisons of the evenness and diversity of the flora to the evenness and diversity of damage types. Although the number of metrics calculated is quite large, given the amount of data that is usually available, the study of insect herbivory in the fossil record still lacks a quantitative framework that can be used to distinguish among different causes of increased insect herbivory and to generate null hypotheses of the magnitude of changes in insect herbivory over time. Moreover, estimates of damage type diversity, the most common metric, are generated with inconsistent sampling standardization routines. Here we demonstrate that coverage-based rarefaction yields valid and reliable estimates of damage type diversity that are robust to differences among floral assemblages in the number of leaves examined, average leaf surface area, and the inclusion of plant organs other than leaves such as seeds and axes. We outline the potential of a theoretical ecospace that combines various metrics to distinguish between potential causes of increased herbivory. We close with a discussion of the most appropriate uses of a theoretical ecospace for insect herbivory, with the overlapping damage type diversities of Paleozoic gymnosperms and Cenozoic angiosperms as a brief case study.

scholarly journals Understanding the ecology of host plant–insect herbivore interactions in the fossil record through bipartite networks

Paleobiology ◽  
2021 ◽  
pp. 1-22
Author(s):  
Anshuman Swain ◽  
S. Augusta Maccracken ◽  
William F. Fagan ◽  
Conrad C. Labandeira
Keyword(s):  
Fossil Record ◽  
Local Community ◽  
Insect Herbivory ◽  
Leaf Damage ◽  
Fossil Flora ◽  
Bipartite Network ◽  
Bipartite Networks ◽  
Plant Insect Interactions ◽  
Central Texas ◽  
Insect Interactions

Abstract Plant–insect associations have been a significant component of terrestrial ecology for more than 400 Myr. Exploring these interactions in the fossil record through novel perspectives provides a window into understanding evolutionary and ecological forces that shaped these interactions. For the past several decades, researchers have documented, described, and categorized fossil evidence of these interactions. Drawing on powerful tools from network science, we propose here a bipartite network representation of fossilized plants and their herbivore-induced leaf damage to understand late Paleozoic plant–insect interactions at the local community level. We focus on four assemblages from north-central Texas, but the methods used in this work are general and can be applied to any well-preserved fossil flora. Network analysis can address key questions in the evolution of insect herbivory that often would be difficult to summarize using standard herbivory metrics.

scholarly journals High richness of insect herbivory from the early Miocene Hindon Maar crater, Otago, New Zealand

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2985 ◽  
Author(s):  
Anna Lena Möller ◽  
Uwe Kaulfuss ◽  
Daphne E. Lee ◽  
Torsten Wappler
Keyword(s):  
New Zealand ◽  
Insect Herbivory ◽  
Terrestrial Ecosystems ◽  
Leaf Damage ◽  
Early Miocene ◽  
Functional Feeding Groups ◽  
Insect Damage ◽  
Southern Beech ◽  
The Antarctic ◽  
Damage Types

Plants and insects are key components of terrestrial ecosystems and insect herbivory is the most important type of interaction in these ecosystems. This study presents the first analysis of associations between plants and insects for the early Miocene Hindon Maar fossil lagerstätte, Otago, New Zealand. A total of 584 fossil angiosperm leaves representing 24 morphotypes were examined to determine the presence or absence of insect damage types. Of these leaves, 73% show signs of insect damage; they comprise 821 occurrences of damage from 87 damage types representing all eight functional feeding groups. In comparison to other fossil localities, the Hindon leaves display a high abundance of insect damage and a high diversity of damage types. Leaves ofNothofagus(southern beech), the dominant angiosperm in the fossil assemblage, exhibit a similar leaf damage pattern to leaves from the nearby mid to late Miocene Dunedin Volcano Group sites but display a more diverse spectrum and much higher percentage of herbivory damage than a comparable dataset of leaves from Palaeocene and Eocene sites in the Antarctic Peninsula.

Ancient Bug Bites on Ancient Plants Record Forest Ecosystem Response to Environmental Perturbations

2013 ◽  
Vol 19 ◽  
pp. 157-174 ◽  
Author(s):  
Ellen D. Currano
Keyword(s):  
Trophic Interactions ◽  
Insect Herbivory ◽  
Fossil Flora ◽  
Local Perturbation ◽  
Insect Damage ◽  
Ecosystem Response ◽  
Insect Feeding ◽  
First Case ◽  
The Impact

Leaf-compression fossils with insect feeding traces are unique in providing rich, direct evidence of two levels in a fossil food web. Plant-insect associations dominate terrestrial trophic interactions, emphasizing the need to understand their ecological and evolutionary history. This paper first discusses methods of recognizing insect herbivore damage on fossil leaves and quantifying fossil insect herbivory. By conducting an unbiased insect damage census, damage frequency (percent of leaves with insect feeding damage), percent of leaf surface area removed by insects, and damage diversity (the number of discrete damage morphotypes, or DTs, found on a fossil flora or individual host plant) can all be measured. Three examples of responses of past plant-insect trophic interactions to environmental stresses are examined. In the first case study, late Oligocene fossil floras from Ethiopia document forest response to local perturbation and key characteristics to recognize disturbance in the plant fossil record. The second case study considers the terrestrial ecosystem response to the catastrophic global perturbation at the Cretaceous–Paleogene boundary. In the third case study, the impact of past global warming events—including the Paleocene–Eocene Thermal Maximum—on insect herbivory is discussed. Productive avenues for further research include: insect damage studies conducted outside the North American Cretaceous and Paleogene, actualistic and taphonomic studies of insect herbivory, and tighter collaboration across paleobotany, paleoentomology, botany, and entomology.

scholarly journals The importance of sampling standardization for comparisons of insect herbivory in deep time: a case study from the late Palaeozoic

2018 ◽  
Vol 5 (3) ◽  
pp. 171991 ◽  
Author(s):  
Sandra R. Schachat ◽  
Conrad C. Labandeira ◽  
S. Augusta Maccracken
Keyword(s):  
Surface Area ◽  
Fossil Record ◽  
Insect Herbivory ◽  
Ecological Factors ◽  
Published Data ◽  
Deep Time ◽  
Leaf Surface Area ◽  
Number Of Leaves ◽  
The Impact

Sampling standardization has not been fully addressed for the study of insect herbivory in the fossil record. The effects of sampling within a single locality were explored almost a decade ago, but the importance of sampling standardization for comparisons of herbivory across space and time has not yet been evaluated. Here, we present a case study from the Permian in which we evaluate the impact of sampling standardization on comparisons of insect herbivory from two localities that are similar in age and floral composition. Comparisons of insect damage type (DT) diversity change dramatically when the number of leaves examined is standardized by surface area. This finding suggests that surface area should always be taken into account for comparisons of DT diversity. In addition, the three most common metrics of herbivory—DT diversity, proportion of leaves herbivorized and proportion of leaf surface area herbivorized—are inherently decoupled from each other. The decoupling of the diversity and intensity of insect herbivory necessitates a reinterpretation of published data because they had been conflated in previous studies. Future studies should examine the divergent ecological factors that underlie these metrics. We conclude with suggestions to guide the sampling and analysis of herbivorized leaves in the fossil record.

scholarly journals Conspiracy of Corporate Networks in Corruption Scandals

2021 ◽  
Vol 9 ◽  
Author(s):  
J. R. Nicolás-Carlock ◽  
I. Luna-Pla
Keyword(s):  
Organized Crime ◽  
Public Procurement ◽  
Bipartite Network ◽  
Corporate Ownership ◽  
Corporate Networks ◽  
State Institutions ◽  
The Public ◽  
Public Resources ◽  
Network Properties ◽  
Network Metrics

Corruption in public procurement transforms state institutions into private entities where public resources get diverted for the benefit of a few. On this matter, much of the discussion centers on the legal fulfillment of the procurement process, while there are fewer formal analyses related to the corporate features which are most likely to signal organized crime and corruption. The lack of systematic evidence on this subject has the potential to bias our understanding of corruption, making it overly focused on the public sector. Nevertheless, corruption scandals worldwide tell of the importance of taking a better look at the misuse and abuse of corporations for corrupt purposes. In this context, the research presented here seeks to contribute to the understanding of the criminal conspiracy of companies involved in public procurement corruption scandals under a network and complexity science perspective. To that end, we make use of a unique dataset of the corporate ownership and management information of four important and recently documented cases of corruption in Mexico, where hundreds of companies were used to embezzle billions of dollars. Under a bipartite network approach, we explore the relations between companies and their personnel (shareholders, legal representatives, administrators, and commissioners) in order to characterize their static and dynamic networked structure. In terms of organized crime and using different network properties, we describe how these companies connect with each other due to the existence of shared personnel with role multiplicity, leading to very different conspiracy networks. To best quantify this behavior, we introduce a heuristic network-based conspiracy indicator that together with other network metrics describes the differences and similarities among the networks associated with each corruption case. Finally, we discuss some public policy elements that might be needed to be considered in anti-corruption efforts related to corporate organized crime.

Spatial scaling of beta diversity in the shallow-marine fossil record

Paleobiology ◽  
2020 ◽  
pp. 1-15
Author(s):  
Tom M. Womack ◽  
James S. Crampton ◽  
Michael J. Hannah
Keyword(s):  
Beta Diversity ◽  
Fossil Record ◽  
Minimum Spanning Tree ◽  
Spatial Scales ◽  
Temporal Trends ◽  
Grid Cell ◽  
Ecological Communities ◽  
Spatial Scaling ◽  
Modern Biology ◽  
Shallow Marine

Abstract Beta diversity quantifies the spatial structuring of ecological communities and is a fundamental partition of biodiversity, central to understanding many macroecological phenomena in modern biology and paleobiology. Despite its common application in ecology, studies of beta diversity in the fossil record are relatively limited at regional spatial scales that are important for understanding macroevolutionary processes. The spatial scaling of beta diversity in the fossil record is poorly understood, but has significant implications due to temporal variation in the spatial distribution of fossil collections and the large spatiotemporal scales typically employed. Here we test the spatial scaling of several common measures of beta diversity using the Cenozoic shallow-marine molluscan fossil record of New Zealand and derive a spatially standardized time series of beta diversity. To measure spatial scaling, we use and compare grid-cell occupancy based on an equal-area grid and summed minimum spanning tree length, both based on reconstructed paleocoordinates of fossil collections. We find that beta diversity is spatially dependent at local to regional scales, regardless of the metric or spatial scaling utilized, and that spatial standardization significantly changes apparent temporal trends of beta diversity and, therefore, inferences about processes driving diversity change.

Paleocommunity and evolutionary ecology of Paleozoic crinoids

1997 ◽  
Vol 3 ◽  
pp. 69-106 ◽  
Author(s):  
Peter F. Holterhoff
Keyword(s):  
Beta Diversity ◽  
Fossil Record ◽  
Evolutionary Ecology ◽  
Alpha Diversity ◽  
High Energy ◽  
Late Ordovician ◽  
Low Energy ◽  
Late Paleozoic ◽  
Common Component ◽  
Early Diversification

Crinoids were a common component of Paleozoic benthic paleocommunities, yet they have been under-utilized in paleoecological analyses. Recent efforts to incorporate disarticulated ossicles into these analyses have greatly increased the robustness of paleoecological patterns noted for the Crinoidea. Analyses of crinoid functional morphology, particularly filtration dynamics, have provided testable hypotheses concerning the distribution of crinoids among benthic environments. These models predict that crinoids with dense-mesh filtration fans should be most common in high energy, shoreward paleoenvironments, whereas open-fan crinoids should be most common in low-energy, offshore paleoenvironments. Review of the Paleozoic fossil record appears to support these general predictions—from the Late Ordovician to the end of the Paleozoic, dense-fan crinoids are most abundant in nearshore paleoenvironments, whereas open-fan crinoids are most abundant offshore.The partitioning of crinoid diversity through the Paleozoic shifted through time. Beta diversity was highest in the Ordovician, implying that the early diversification of crinoids was focused on partitioning the benthic landscape among taxa. Beta diversity was quite low by the late Paleozoic, however, local and within-habitat alpha diversity was much greater than during the Ordovician. This resulted in generally higher levels of eurytopy in the late Paleozoic compared to the Ordovician. Patterns of faunal disassembly associated with regional extinctions in North America during the Ordovician and Permian underscore the differences in the paleoecology of these crinoid faunas.

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