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Brigatti E, Amazonas Mendes EA. Testing macroecological theories in cryptocurrency market: neutral models cannot describe diversity patterns and their variation. ROYAL SOCIETY OPEN SCIENCE 2022; 9:212005. [PMID: 35425637 PMCID: PMC9006011 DOI: 10.1098/rsos.212005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/10/2022] [Indexed: 05/03/2023]
Abstract
We develop an analysis of the cryptocurrency market borrowing methods and concepts from ecology. This approach makes it possible to identify specific diversity patterns and their variation, in close analogy with ecological systems, and to characterize the cryptocurrency market in an effective way. At the same time, it shows how non-biological systems can have an important role in contrasting different ecological theories and in testing the use of neutral models. The study of the cryptocurrencies abundance distribution and the evolution of the community structure strongly indicates that these statistical patterns are not consistent with neutrality. In particular, the necessity to increase the temporal change in community composition when the number of cryptocurrencies grows, suggests that their interactions are not necessarily weak. The analysis of the intraspecific and interspecific interdependency supports this fact and demonstrates the presence of a market sector influenced by mutualistic relations. These latest findings challenge the hypothesis of weakly interacting symmetric species, the postulate at the heart of neutral models.
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Affiliation(s)
- Edgardo Brigatti
- Instituto de Física, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, Cidade Universitária, 21941-972 Rio de Janeiro, Brazil
| | - Estevan Augusto Amazonas Mendes
- Instituto de Física, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, Cidade Universitária, 21941-972 Rio de Janeiro, Brazil
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Diaz RM, Ye H, Ernest SKM. Empirical abundance distributions are more uneven than expected given their statistical baseline. Ecol Lett 2021; 24:2025-2039. [PMID: 34142760 DOI: 10.1111/ele.13820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/12/2021] [Accepted: 04/30/2021] [Indexed: 11/30/2022]
Abstract
Exploring and accounting for the emergent properties of ecosystems as complex systems is a promising horizon in the search for general processes to explain common ecological patterns. For example the ubiquitous hollow-curve form of the species abundance distribution is frequently assumed to reflect ecological processes structuring communities, but can also emerge as a statistical phenomenon from the mathematical definition of an abundance distribution. Although the hollow curve may be a statistical artefact, ecological processes may induce subtle deviations between empirical species abundance distributions and their statistically most probable forms. These deviations may reflect biological processes operating on top of mathematical constraints and provide new avenues for advancing ecological theory. Examining ~22,000 communities, we found that empirical SADs are highly uneven and dominated by rare species compared to their statistical baselines. Efforts to detect deviations may be less informative in small communities-those with few species or individuals-because these communities have poorly resolved statistical baselines. The uneven nature of many empirical SADs demonstrates a path forward for leveraging complexity to understand ecological processes governing the distribution of abundance, while the issues posed by small communities illustrate the limitations of using this approach to study ecological patterns in small samples.
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Affiliation(s)
- Renata M Diaz
- School of Natural Resources and Environment, University of Florida, Gainesville, FL, USA
| | - Hao Ye
- Health Science Center Libraries, University of Florida, Gainesville, FL, USA
| | - S K Morgan Ernest
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
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Gillespie MAK, Birkemoe T, Sverdrup-Thygeson A. Interactions between body size, abundance, seasonality, and phenology in forest beetles. Ecol Evol 2017; 7:1091-1100. [PMID: 28303180 PMCID: PMC5306008 DOI: 10.1002/ece3.2732] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/07/2016] [Accepted: 12/18/2016] [Indexed: 12/02/2022] Open
Abstract
Body size correlates with a large number of species traits, and these relationships have frequently been used to explain patterns in populations, communities, and ecosystems. However, diverging patterns occur, and there is a need for more data on different taxa at different scales. Using a large dataset of 155,418 individual beetles from 588 species collected over 13 years of sampling in Norway, we have explored whether body size predicts abundance, seasonality, and phenology in insects. Seasonality is estimated here by flight activity period length and phenology by peak activity. We develop several methods to estimate these traits from low‐resolution sampling data. The relationship between abundance and body size was significant and as expected; the smaller species were more abundant. However, smaller species tended to fly for longer periods of the summer and peaked in midsummer, while larger species were restricted to shorter temporal windows. Further analysis of repeated sampling from a single location suggested that smaller species had increased flight period lengths in warmer years, but larger species showed the opposite pattern. The results 1) indicate that smaller species are likely to be disproportionately valuable in ecological interactions, and 2) provide potential insights into the traits influencing the vulnerability of some larger species to disturbances and climate change.
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Affiliation(s)
- Mark A K Gillespie
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway; Department of Science & Engineering Western Norway University of Applied Sciences Sogndal Norway
| | - Tone Birkemoe
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway
| | - Anne Sverdrup-Thygeson
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway
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Blonder B, Sloat L, Enquist BJ, McGill B. Separating macroecological pattern and process: comparing ecological, economic, and geological systems. PLoS One 2014; 9:e112850. [PMID: 25383874 PMCID: PMC4226609 DOI: 10.1371/journal.pone.0112850] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/16/2014] [Indexed: 11/18/2022] Open
Abstract
Theories of biodiversity rest on several macroecological patterns describing the relationship between species abundance and diversity. A central problem is that all theories make similar predictions for these patterns despite disparate assumptions. A troubling implication is that these patterns may not reflect anything unique about organizational principles of biology or the functioning of ecological systems. To test this, we analyze five datasets from ecological, economic, and geological systems that describe the distribution of objects across categories in the United States. At the level of functional form ('first-order effects'), these patterns are not unique to ecological systems, indicating they may reveal little about biological process. However, we show that mechanism can be better revealed in the scale-dependency of first-order patterns ('second-order effects'). These results provide a roadmap for biodiversity theory to move beyond traditional patterns, and also suggest ways in which macroecological theory can constrain the dynamics of economic systems.
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Affiliation(s)
- Benjamin Blonder
- Sky School, University of Arizona, Tucson, Arizona, United States of America
| | - Lindsey Sloat
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, United States of America
| | - Brian J. Enquist
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, United States of America
- Santa Fe Institute, Santa Fe, New Mexico, United States of America
| | - Brian McGill
- School of Biology and Ecology, University of Maine, Orono, Maine, United States of America
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Locey KJ, White EP. How species richness and total abundance constrain the distribution of abundance. Ecol Lett 2013; 16:1177-85. [PMID: 23848604 DOI: 10.1111/ele.12154] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 02/17/2013] [Accepted: 06/14/2013] [Indexed: 11/29/2022]
Abstract
The species abundance distribution (SAD) is one of the most intensively studied distributions in ecology and its hollow-curve shape is one of ecology's most general patterns. We examine the SAD in the context of all possible forms having the same richness (S) and total abundance (N), i.e. the feasible set. We find that feasible sets are dominated by similarly shaped hollow curves, most of which are highly correlated with empirical SADs (most R(2) values > 75%), revealing a strong influence of N and S on the form of the SAD and an a priori explanation for the ubiquitous hollow curve. Empirical SADs are often more hollow and less variable than the majority of the feasible set, revealing exceptional unevenness and relatively low natural variability among ecological communities. We discuss the importance of the feasible set in understanding how general constraints determine observable variation and influence the forms of predicted and empirical patterns.
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Affiliation(s)
- Kenneth J Locey
- Department of Biology, Utah State University, Logan, UT 84322, USA.
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McGill BJ, Nekola JC. Mechanisms in macroecology: AWOL or purloined letter? Towards a pragmatic view of mechanism. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2009.17771.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nekola JC, Brown JH. The wealth of species: ecological communities, complex systems and the legacy of Frank Preston. Ecol Lett 2007; 10:188-96. [PMID: 17305802 DOI: 10.1111/j.1461-0248.2006.01003.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
General statistical patterns in community ecology have attracted considerable recent debate. Difficulties in discriminating among mathematical models and the ecological mechanisms underlying them are likely related to a phenomenon first described by Frank Preston. He noted that the frequency distribution of abundances among species was uncannily similar to the Boltzmann distribution of kinetic energies among gas molecules and the Pareto distribution of incomes among wage earners. We provide additional examples to show that four different 'distributions of wealth' (species abundance distributions, species-area and species-time relations, and distance decay of compositional similarity) are not unique to ecology, but have analogues in other physical, geological, economic and cultural systems. Because these appear to be general statistical patterns characteristic of many complex dynamical systems they are likely not generated by uniquely ecological mechanistic processes.
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Affiliation(s)
- Jeffrey C Nekola
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
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Basset Y, Novotny V, Miller SE, Springate ND. Assessing the impact of forest disturbance on tropical invertebrates: some comments. J Appl Ecol 2004. [DOI: 10.1046/j.1365-2664.1998.00311.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Yves Basset
- International Institute of Entomology, London, UK;
| | - Vojtech Novotny
- Institute of Entomology, Czech Academy of Sciences & University of South Bohemia, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic;
| | - Scott E. Miller
- Bishop Museum, Honolulu & International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya; and
| | - Neil D. Springate
- The Natural History Museum, Entomology Department, Cromwell Road, London SW7 5BD, UK
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PETERSON A, SLADE NORMAN. Extrapolating inventory results into biodiversity estimates and the importance of stopping rules. DIVERS DISTRIB 1998. [DOI: 10.1046/j.1365-2699.1998.00021.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Relations between abundance, body size and species number in British birds and mammals. Philos Trans R Soc Lond B Biol Sci 1997. [DOI: 10.1098/rstb.1996.0023] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
British birds and mammals are compared in terms of their frequency distributions of abundance and body mass and in respect of the relation between abundance and body mass. Body masses of non-flying mammals are greater than those of resident birds which are, in turn, heavier than migrants; bats are lightest. The frequency distribution of masses are close to log-Normal for each of these groups, though their variances and skews differ. Differences in mean abundances (which are log-Normally distributed) parallel those in body mass. In each group, abundance declines with body mass: the exponent of the relation is close to the value of —0.75 predicted by the ‘energetic equivalence’ rule though not significantly different from the value of — 1.0 predicted by the ‘biomass equivalence’ rule. At comparable masses, species of non-flying mammals are more abundant than resident birds, migrant birds and bats by approximately 45, 300 and 200 times, respectively. The similarity between birds and bats in this regard may be no more than coincidental but it may be related to ecological similarities related to flight. The metabolic rates of non-flying mammals may be generally lower than those of birds and bats but not sufficiently to account for their much greater abundances.
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Cotgreave P. The relationship between body size and population abundance in animals. Trends Ecol Evol 1993; 8:244-8. [DOI: 10.1016/0169-5347(93)90199-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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