Alpha, beta, or gamma: where does all the diversity go?

Paleobiology ◽  
1988 ◽  
Vol 14 (3) ◽  
pp. 221-234 ◽  
Author(s):  
J. John Sepkoski
Keyword(s):  
Beta Diversity ◽  
Alpha Diversity ◽  
Taxonomic Richness ◽  
Soft Bottom ◽  
Gamma Diversity ◽  
Data Set ◽  
Alpha And Beta Diversity ◽  
Community Or ◽  
Global Diversity ◽  
Measured Change

Global taxonomic richness is affected by variation in three components: within-community, or alpha, diversity; between-community, or beta, diversity; and between-region, or gamma, diversity. A data set consisting of 505 faunal lists distributed among 40 stratigraphic intervals and six environmental zones was used to investigate how variation in alpha and beta diversity influenced global diversity through the Paleozoic, and especially during the Ordovician radiations. As first shown by Bambach (1977), alpha diversity increased by 50 to 70 percent in offshore marine environments during the Ordovician and then remained essentially constant for the remainder of the Paleozoic. The increase is insufficient, however, to account for the 300 percent rise observed in global generic diversity. It is shown that beta diversity among level, soft-bottom communities also increased significantly during the early Paleozoic. This change is related to enhanced habitat selection, and presumably increased overall specialization, among diversifying taxa during the Ordovician radiations. Combined with alpha diversity, the measured change in beta diversity still accounts for only about half of the increase in global diversity. Other sources of increase are probably not related to variation in gamma diversity but rather to appearance and/or expansion of organic reefs, hardground communities, bryozoan thickets, and crinoid gardens during the Ordovician.

scholarly journals Patterns of diversity on the Paleozoic shelf: implications for controls on clade history

1992 ◽  
Vol 6 ◽  
pp. 266-266 ◽  
Author(s):  
J. John Sepkoski ◽  
Arnold I. Miller
Keyword(s):  
Beta Diversity ◽  
Spatial Scales ◽  
Alpha Diversity ◽  
Physical Geography ◽  
Local Communities ◽  
Dominant Factor ◽  
Ecological Processes ◽  
Alpha And Beta Diversity ◽  
Global Diversity ◽  
Local Ecology

Global diversity often is treated as a barometer of evolutionary success of clades without reference to their occurrence in ecological or biogeographical space. But global diversity is a composite of various spatial scales: alpha diversity, the number of taxa co-occurring in local communities; beta diversity, the distinction in taxonomic composition among local communities; and gamma diversity, the distinction, or degree of endemism, among geographic provinces, It has been argued by some workers that global diversity correlates strongly with alpha (and beta) diversity but by others that provinciality is the principal control of global patterns. The distinction is important, implicating either ecological processes (“adaptation”) or physical geography (“contingency”) as the major factor in expansion of clades.We have examined the ecological half of this problem with a data base comprising 505 fossil assemblages sampled from Paleozoic strata of Laurentian North America. On the basis of associated sedimentary characteristics, each assemblage has been assigned to one of six environmental categories, ranging from onshore peritidal situations to offshore basinal conditions. For each taxonomic order and class, average numbers of genera in each category have been determined for each of 18 time units. These average alpha diversities have been contoured on time-environment diagrams and compared to patterns of global diversity.Three major generalizations are derived from these diagrams:1. Major groups tend to be environmentally conservative, maintaining their life zones of maximum and minimum alpha diversity over vast stretches of time.2. Onshore-offshore shifts are most common during early expansion or late contraction of groups, when their global diversity is rapidly waxing or (more slowly) waning.3. Maxima and minima in global diversity within the groups through time, with few exceptions, are reflected in alpha diversity as fluctuations within the environments of maximum richness and/or as variations in the range of environments occupied.The last observation indicates a tight link between local ecology and global diversity, although the direction of causation is not unambiguous: alpha diversity could be reflecting only the global pool from which species can be recruited into local communities. However, in view of the onshore-offshore shifts during early and late histories of clades we conclude that local ecology is the dominant factor in controlling global diversity, and provinciality is secondary.

scholarly journals Alpha-, beta-, and gamma-diversity of bacteria varies across global habitats

2020 ◽  
Author(s):  
Kendra E. Walters ◽  
Jennifer B.H. Martiny
Keyword(s):  
Beta Diversity ◽  
Multiple Scales ◽  
Agricultural Soils ◽  
Bacterial Species ◽  
Alpha Diversity ◽  
Global Scale ◽  
Gamma Diversity ◽  
Alpha And Beta Diversity ◽  
Alpha Beta ◽  
Beta And Gamma Diversity

AbstractBacteria are essential parts of ecosystems and are the most abundant organisms on the planet. Yet, we still do not know which habitats support the highest diversity of bacteria across multiple scales. We analyzed alpha-, beta-, and gamma-diversity of bacterial assemblages using 11,680 samples compiled by the Earth Microbiome Project. We found that soils contained the highest bacterial richness within a single sample (alpha-diversity), but sediment assemblages were the most diverse at a global scale (gamma-diversity). Sediment, biofilms/mats, and inland water exhibited the most variation in community composition among geographic locations (beta-diversity). Within soils, agricultural lands, hot deserts, grasslands, and shrublands contained the highest richness, while forests, cold deserts, and tundra biomes consistently harbored fewer bacterial species. Surprisingly, agricultural soils encompassed similar levels of beta-diversity as other soil biomes. These patterns were robust to the alpha- and beta-diversity metrics used and the taxonomic binning approach. Overall, the results support the idea that spatial environmental heterogeneity is an important driver of bacterial diversity.

scholarly journals Effect of Bovine MFGM and LF in Infant Formula on Gut Microbiome and Metabolome at Four Months of Age

2021 ◽  
Author(s):  
Maciej Chichlowski ◽  
Nicholas Bokulich ◽  
Cheryl L Harris ◽  
Jennifer L Wampler ◽  
Fei Li ◽  
...  
Keyword(s):  
Infant Formula ◽  
Beta Diversity ◽  
Milk Fat ◽  
Alpha Diversity ◽  
Illumina Miseq ◽  
Rrna Gene ◽  
Term Infants ◽  
Linear Discriminant ◽  
Alpha And Beta Diversity ◽  
Metabolite Profiles

Abstract Background Milk fat globule membrane (MFGM) and lactoferrin (LF) are human milk bioactive components demonstrated to support gastrointestinal (GI) and immune development. Significantly fewer diarrhea and respiratory-associated adverse events through 18 months of age were previously reported in healthy term infants fed a cow's milk-based infant formula with added source of bovine MFGM and bovine LF through 12 months of age. Objectives To compare microbiota and metabolite profiles in a subset of study participants. Methods Stool samples were collected at Baseline (10–14 days of age) and Day 120 (MFGM + LF: 26, Control: 33). Bacterial community profiling was performed via16S rRNA gene sequencing (Illumina MiSeq) and alpha and beta diversity were analyzed (QIIME 2). Differentially abundant taxa were determined using Linear discriminant analysis effect size (LefSE) and visualized (Metacoder). Untargeted stool metabolites were analyzed (HPLC/mass spectroscopy) and expressed as the fold-change between group means (Control: MFGM + LF ratio). Results Alpha diversity increased significantly in both groups from baseline to 4 months. Subtle group differences in beta diversity were demonstrated at 4 months (Jaccard distance; R2 = 0.01, P = 0.042). Specifically, Bacteroides uniformis and Bacteroides plebeius were more abundant in the MFGM + LF group at 4 months. Metabolite profile differences for MFGM + LF vs Control included: lower fecal medium chain fatty acids, deoxycarnitine, and glycochenodeoxycholate, and some higher fecal carbohydrates and steroids (P < 0.05). After applying multiple test correction, the differences in stool metabolomics were not significant. Conclusions Addition of bovine MFGM and LF in infant formula was associated with subtle differences in stool microbiome and metabolome by four months of age, including increased prevalence of Bacteroides species. Stool metabolite profiles may be consistent with altered microbial metabolism. Trial registration:  https://clinicaltrials.gov/ct2/show/NCT02274883).

Partitioning tree diversity patterns to prioritize conservation investments

2021 ◽  
pp. 1-9
Author(s):  
Patrick F McKenzie ◽  
Gwenllian D Iacona ◽  
Eric R Larson ◽  
Paul R Armsworth
Keyword(s):  
Protected Areas ◽  
Predictive Models ◽  
Tree Species ◽  
Beta Diversity ◽  
Distribution Data ◽  
Gamma Diversity ◽  
Conservation Practice ◽  
Alpha And Beta Diversity ◽  
Community Turnover ◽  
Data Limitations

Summary The available tools and approaches to inform conservation decisions commonly assume detailed distribution data. We examine how well-established ecological concepts about patterns in local richness and community turnover can help overcome data limitations when planning future protected areas. To inform our analyses, we surveyed tree species in protected areas in the southern Appalachian Mountains in the eastern USA. We used the survey data to construct predictive models for alpha and beta diversity based on readily observed biophysical variables and combined them to create a heuristic that could predict among-site richness in trees (gamma diversity). The predictive models suggest that site elevation and latitude in this montane system explain much of the variation in alpha and beta diversity in tree species. We tested how well resulting protected areas would represent species if a conservation planner lacking detailed species inventories for candidate sites were to rely only on our alpha, beta and gamma diversity predictions. Our approach selected sites that, when aggregated, covered a large proportion of the overall species pool. The combined gamma diversity models performed even better when we also accounted for the cost of protecting sites. Our results demonstrate that classic community biogeography concepts remain highly relevant to conservation practice today.

scholarly journals Gut Microbiome in Psoriasis: An Updated Review

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 463
Author(s):  
Mariusz Sikora ◽  
Albert Stec ◽  
Magdalena Chrabaszcz ◽  
Aleksandra Knot ◽  
Anna Waskiel-Burnat ◽  
...  
Keyword(s):  
Gut Microbiome ◽  
Beta Diversity ◽  
Large Scale ◽  
Skin Diseases ◽  
Intestinal Barrier ◽  
Alpha Diversity ◽  
Current Data ◽  
Intestinal Microbiome ◽  
Microbial Composition ◽  
Alpha And Beta Diversity

(1) Background: A growing body of evidence highlights that intestinal dysbiosis is associated with the development of psoriasis. The gut–skin axis is the novel concept of the interaction between skin diseases and microbiome through inflammatory mediators, metabolites and the intestinal barrier. The objective of this study was to synthesize current data on the gut microbial composition in psoriasis. (2) Methods: We conducted a systematic review of studies investigating intestinal microbiome in psoriasis, using the PRISMA checklist. We searched MEDLINE, EMBASE, and Web of Science databases for relevant published articles (2000–2020). (3) Results: All of the 10 retrieved studies reported alterations in the gut microbiome in patients with psoriasis. Eight studies assessed alpha- and beta-diversity. Four of them reported a lack of change in alpha-diversity, but all confirmed significant changes in beta-diversity. At the phylum-level, at least two or more studies reported a lower relative abundance of Bacteroidetes, and higher Firmicutes in psoriasis patients versus healthy controls. (4) Conclusions: There is a significant association between alterations in gut microbial composition and psoriasis; however, there is high heterogeneity between studies. More unified methodological standards in large-scale studies are needed to understand microbiota’s contribution to psoriasis pathogenesis and its modulation as a potential therapeutic strategy.

scholarly journals AB1232 ORAL DYSBIOSIS REFLECTS THE IMMUNOLOGICAL ALTERATION OF RA REGARDING TO ACPA AND HLA DRB1*SE: NAGASAKI ISLAND STUDY

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1907.2-1907
Author(s):  
Y. Tsuji ◽  
M. Tamai ◽  
S. Morimoto ◽  
D. Sasaki ◽  
M. Nagayoshi ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Healthy Subjects ◽  
Microbial Community Composition ◽  
Alpha Diversity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rrna Gene ◽  
Oral Microbiota ◽  
Unifrac Distance ◽  
Alpha And Beta Diversity ◽  
The Difference

Background:Anti-citrullinated protein antibody (ACPA) production is observed in several organs even prior to the onset of rheumatoid arthritis (RA), and oral mucosa is considered to be one of the important tissues. The presence of HLA-DRB1*SE closely associates with ACPA production. Saliva is considered to reflect the oral microbiota including periodontal disease. Alteration of oral microbiota of RA becomes to be normalized by DMARDs treatment, however, the interaction of HLA-DRB1*SE, ACPA and oral microbiota of RA patients remains to be elucidated.Objectives:The Nagasaki Island Study, which had started in 2014 collaborating with Goto City, is intended for research of the preclinical stage of RA, including ACPA/HLA genotype screening and ultrasound and magnetic resonance imaging examinations in high-risk subjects. Using the samples accumulated in this cohort, we have tried to investigate the difference of oral microbiota among RA patients and healthy subjects regarding to ACPA and HLA-DRB1*SE.Methods:Blood and salivary samples were obtained from 1422 subjects out of 4276 who have participated in the Nagasaki Island Study from 2016 to 2018. ACPA positivity was 1.7 % in total. Some of RA patients resided in Goto City participated in the Nagasaki Island Study. At this point, we selected 291 subjects, who were ACPA positive non-RA healthy subjects (n=22) and patients with RA (n=33, 11 subjects were ACPA positive and 22 ACPA negative respectively) as the case, age and gender matched ACPA negative non-RA healthy subjects (n=236) as the control. ACPA was measured by an enzyme-linked immunosorbent assay, and HLA genotyping was quantified by next-generation sequencing (Ref.1). The operational taxonomic unit (OUT) analysis using 16S rRNA gene sequencing were performed. The richness of microbial diversity within-subject (alpha diversity) was scaled via Shannon entropy. The dissimilarity between microbial community composition was calculated using Bray-Curtis distance as a scale, and differences between groups (beta diversity) were tested by permutational multivariate analysis of variance (PERMANOVA). In addition, UniFrac distance calculated in consideration of the distance on the phylogenetic tree were performed.Results:Median age 70 y.o., % Female 58.8 %. Among RA and non-RA subjects, not alpha diversity but beta diversity was statistically significance (p=0.022, small in RA). In RA subjects, both alpha and beta diversity is small (p<0.0001), especially significant in ACPA positive RA (Figure 1). Amongt RA subjects, presence of HLA-DRB1*SE did not show the difference but the tendency of being small of alpha diversity (p=0.29).Conclusion:Our study has suggested for the first time the association of oral microbiota alteration with the presence of ACPA and HLA-DRB1*SE. Oral dysbiosis may reflect the immunological status of patients with RA.References:[1]Kawaguchi S, et al. Methods Mol Biol 2018;1802: 22Disclosure of Interests:None declared

scholarly journals Diversity Indices of Plant Communities and Their Rhizosphere Microbiomes: An Attempt to Find the Connection

2021 ◽  
Vol 9 (11) ◽  
pp. 2339
Author(s):  
Aleksei O. Zverev ◽  
Arina A. Kichko ◽  
Aleksandr G. Pinaev ◽  
Nikolay A. Provorov ◽  
Evgeny E. Andronov
Keyword(s):  
Microbial Communities ◽  
Plant Communities ◽  
Plant Diversity ◽  
Beta Diversity ◽  
Mutual Influence ◽  
Plant Root ◽  
Alpha Diversity ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
Highly Correlated

The rhizosphere community represents an “ecological interface” between plant and soil, providing the plant with a number of advantages. Despite close connection and mutual influence in this system, the knowledge about the connection of plant and rhizosphere diversity is still controversial. One of the most valuable factors of this uncertainty is a rough estimation of plant diversity. NGS sequencing can make the estimations of the plant community more precise than classical geobotanical methods. We investigate fallow and crop sites, which are similar in terms of environmental conditions and soil legacy, yet at the same time are significantly different in terms of plant diversity. We explored amplicons of both the plant root mass (ITS1 DNA) and the microbial communities (16S rDNA); determined alpha- and beta-diversity indices and their correlation, and performed differential abundance analysis. In the analysis, there is no correlation between the alpha-diversity indices of plants and the rhizosphere microbial communities. The beta-diversity between rhizosphere microbial communities and plant communities is highly correlated (R = 0.866, p = 0.01). ITS1 sequencing is effective for the description of plant root communities. There is a connection between rhizosphere communities and the composition of plants, but on the alpha-diversity level we found no correlation. In the future, the connection of alpha-diversities should be explored using ITS1 sequencing, even in more similar plant communities—for example, in different synusia.

Impact of intrapartum antibiotics on the infant gastrointestinal microbiome: a narrative review

2021 ◽  
pp. archdischild-2021-322590
Author(s):  
Laura Diamond ◽  
Rachel Wine ◽  
Shaun K Morris
Keyword(s):  
Gestational Age ◽  
Beta Diversity ◽  
Mode Of Delivery ◽  
Alpha Diversity ◽  
First Year ◽  
Feeding Method ◽  
Alpha And Beta Diversity ◽  
Ovid Medline ◽  
First Year Of Life ◽  
The Impact

BackgroundThe composition of the infant gastrointestinal (GI) microbiome has been linked to adverse long-term health outcomes and neonatal sepsis. Several factors are known to impact the composition of the microbiome, including mode of delivery, gestational age, feeding method and exposure to antibiotics. The impact of intrapartum antibiotics (IPAs) on the infant microbiome requires further research.ObjectiveWe aimed to evaluate the impact of IPAs on the infant GI microbiome.MethodsWe searched Ovid MEDLINE and Embase Classic+Embase for articles in English reporting on the microbiome of infants exposed to IPAs from the date of inception to 3 January 2021. Primary outcomes included abundance and colonisation of Bifidobacterium and Lactobacillus, as well as alpha and beta diversity.Results30 papers were included in this review. In the first year of life, following exposure to IPAs, 30% (6/20) of infant cohorts displayed significantly reduced Bifidobacterium, 89% (17/19) did not display any significant differences in Lactobacillus colonisation, 21% (7/34) displayed significantly reduced alpha diversity and 35% (12/34) displayed alterations in beta diversity. Results were further stratified by delivery, gestational age (preterm or full term) and feeding method.ConclusionsIPAs impact the composition of the infant GI microbiome, resulting in possible reductions Bifidobacterium and alpha diversity, and possible alterations in beta diversity. Our findings may have implications for maternal and neonatal health, including interventions to prevent reductions in health-promoting bacteria (eg, probiotics) and IPA class selection.

scholarly journals Evidence supporting the microbiota–gut–brain axis in a songbird

2020 ◽  
Vol 16 (11) ◽  
pp. 20200430
Author(s):  
Morgan C. Slevin ◽  
Jennifer L. Houtz ◽  
David J. Bradshaw ◽  
Rindy C. Anderson
Keyword(s):  
Gut Microbiome ◽  
Beta Diversity ◽  
Alpha Diversity ◽  
Cloacal Swab ◽  
Cognitive Tasks ◽  
Captive Population ◽  
Wild Populations ◽  
Alpha And Beta Diversity ◽  
Microbiome Research ◽  
Host Development

Recent research in mammals supports a link between cognitive ability and the gut microbiome, but little is known about this relationship in other taxa. In a captive population of 38 zebra finches ( Taeniopygia guttata ), we quantified performance on cognitive tasks measuring learning and memory. We sampled the gut microbiome via cloacal swab and quantified bacterial alpha and beta diversity. Performance on cognitive tasks related to beta diversity but not alpha diversity. We then identified differentially abundant genera influential in the beta diversity differences among cognitive performance categories. Though correlational, this study provides some of the first evidence of an avian microbiota–gut–brain axis, building foundations for future microbiome research in wild populations and during host development.

scholarly journals Unimodal Relationships of Understory Alpha and Beta Diversity along Chronosequence in Coppiced and Unmanaged Beech Forests

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 101 ◽  
Author(s):  
Sándor Bartha ◽  
Roberto Canullo ◽  
Stefano Chelli ◽  
Giandiego Campetella
Keyword(s):  
Beta Diversity ◽  
Management Practices ◽  
Multiple Scales ◽  
Forest Succession ◽  
Spatial Scales ◽  
Alpha Diversity ◽  
Structural Diversity ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
Coppice Management

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 × 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray–Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value.

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