scholarly journals Macroscale estimates of species abundance reveal evolutionary drivers of biodiversity

2018 ◽  
Author(s):  
Keiichi Fukaya ◽  
Buntarou Kusumoto ◽  
Takayuki Shiono ◽  
Junichi Fujinuma ◽  
Yasuhiro Kubota
Keyword(s):  
Point Mutation ◽  
Neutral Theory ◽  
Species Abundance ◽  
Species Abundance Distribution ◽  
Absolute Size ◽  
Evolutionary Diversification ◽  
Ecological Patterns ◽  
Neutral Theory Of Biodiversity ◽  
Number Of Individuals

AbstractEvolutionary processes underpin the biodiversity on the planet. Theories advocate that the form of the species abundance distribution (SAD), presented by the number of individuals for each species within an ecological community, is intimately linked to speciation modes such as point mutation and random fission. This prediction has rarely been, however, verified empirically; the fact that species abundance data can be obtained only from local communities critically limits our ability to infer the role of macroevolution in shaping ecological patterns. Here, we developed a novel statistical model to estimate macroscale SADs, the hidden macroecological property, by integrating spatially replicated multispecies detection-nondetection observations and the data on species geographic distributions. We determined abundance of 1,248 woody plant species at a 10 km grid square resolution over East Asian islands across subtropical to temperate biomes, which produced a metacommunity (i.e. species pool) SAD in four insular ecoregions along with its absolute size. The metacommunity SADs indicated lognormal-like distributions, which were well explained by the unified neutral theory of biodiversity and biogeography (UNTB) with protracted speciation, a mode of speciation intermediate between point mutation and random fission. Furthermore, the analyses yielded an estimate of speciation rate in each region that highlighted the importance of geographic characteristics in macroevolutionary processes and predicted the average species lifetime that was congruent with previous estimates. The estimation of macroscale SADs plays a remarkable role in revealing evolutionary diversification of regional species pools.

scholarly journals Predicting community structure in snakes on Eastern Nearctic islands using ecological neutral theory and phylogenetic methods

2015 ◽  
Vol 282 (1819) ◽  
pp. 20151700 ◽  
Author(s):  
Frank T. Burbrink ◽  
Alexander D. McKelvy ◽  
R. Alexander Pyron ◽  
Edward A. Myers
Keyword(s):  
Community Structure ◽  
Island Biogeography ◽  
Neutral Theory ◽  
Species Abundance ◽  
Phylogenetic Methods ◽  
Island Communities ◽  
Theory Of Island Biogeography ◽  
Neutral Theory Of Biodiversity ◽  
Neutral Models ◽  
Better Than

Predicting species presence and richness on islands is important for understanding the origins of communities and how likely it is that species will disperse and resist extinction. The equilibrium theory of island biogeography (ETIB) and, as a simple model of sampling abundances, the unified neutral theory of biodiversity (UNTB), predict that in situations where mainland to island migration is high, species-abundance relationships explain the presence of taxa on islands. Thus, more abundant mainland species should have a higher probability of occurring on adjacent islands. In contrast to UNTB, if certain groups have traits that permit them to disperse to islands better than other taxa, then phylogeny may be more predictive of which taxa will occur on islands. Taking surveys of 54 island snake communities in the Eastern Nearctic along with mainland communities that have abundance data for each species, we use phylogenetic assembly methods and UNTB estimates to predict island communities. Species richness is predicted by island area, whereas turnover from the mainland to island communities is random with respect to phylogeny. Community structure appears to be ecologically neutral and abundance on the mainland is the best predictor of presence on islands. With regard to young and proximate islands, where allopatric or cladogenetic speciation is not a factor, we find that simple neutral models following UNTB and ETIB predict the structure of island communities.

scholarly journals Myxomycetes of the Caramoan Islands and an update on the species found in the Bicol Peninsula, Philippines

2021 ◽  
Vol 14 (1) ◽  
Keyword(s):  
Clustering Analysis ◽  
Diversity Index ◽  
Neutral Theory ◽  
Taxonomic Diversity ◽  
Diversity Indices ◽  
Slime Molds ◽  
Close Proximity ◽  
Ecological Patterns ◽  
Percentage Similarity ◽  
Neutral Theory Of Biodiversity

The main objective of this study was to characterize the assemblages of myxomycetes on isolated Philippine islands through a correlational study using geographical and ecological distance in the Caramoan Islands, including an updated checklist of the myxomycetes of the Bicol Peninsula. Four islands of varying sizes and distances from each other, but all within relatively close proximity to the mainland of the Bicol Peninsula, were surveyed. A combination of traditional and more contemporary ecological tools was used to analyze diversity indices among and between the islands. Among the four islands, Matukad Island recorded the highest species richness (46.8) and taxonomic diversity index (2.6), while ranking next to Lahos island in terms of species diversity (7.9). Pairwise comparisons using community similarity indices and clustering analysis consistently showed that Lahos and Matukad are the most similar to each other, while also being closer to one another but situated farthest from the mainland. On the other hand, the two smallest islands, which were also closest to each other and to the mainland, grouped together using clustering analysis but recorded the lowest pairwise percentage similarity value. The ecological patterns in this study appear to follow the unified neutral theory of biodiversity and biogeography more than the insular biogeography theory. In addition, this study added 16 new morphospecies to the list of myxomycetes known from the Bicol Peninsula, which brings the total to 73, including one new record for the country [Lamproderma arcyrioides (Sommerf.) Rostaf.] KEYWORDS: slime molds, insular, biodiversity, paleotropics, unified netural theory

scholarly journals Empirical abundance distributions are more uneven than expected given their statistical baseline

2021 ◽  
Author(s):  
Renata M. Diaz ◽  
Hao Ye ◽  
S. K. Morgan Ernest
Keyword(s):  
Species Abundance ◽  
Ecological Theory ◽  
Small Samples ◽  
Curve Shape ◽  
Ecological Processes ◽  
Small Communities ◽  
Number Of Species ◽  
Ecological Patterns ◽  
Species Abundance Distributions ◽  
Number Of Individuals

AbstractThe prevalence of the species abundance distribution’s hollow-curve shape across many communities is frequently assumed to reflect ecological processes structuring communities. However, this hollow curve can also emerge as a statistical phenomenon of dividing a particular number of individuals into a given number of species. While 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. Examining ~22,000 communities, we found that empirical species abundance distributions are more skewed and uneven than their statistical baselines. However, small communities – with few species or individuals – exhibit poorly-resolved statistical baselines, thereby reducing our capacity to detect deviations. The extraordinarily skewed and uneven nature of empirical species abundance distributions provides new avenues for testing ecological theory, while the issues posed by small communities illustrate the limitations of statistical baselines for studying ecological patterns in small samples.

scholarly journals Species diversity rises exponentially with the number of available resources in a multi-trait competition model

2018 ◽  
Vol 285 (1885) ◽  
pp. 20181273 ◽  
Author(s):  
Andres Laan ◽  
Gonzalo G. de Polavieja
Keyword(s):  
Neutral Theory ◽  
Species Abundance ◽  
Ecosystem Models ◽  
Stochastic Effects ◽  
Large Numbers ◽  
Species Abundance Distributions ◽  
Restoring Forces ◽  
Neutral Theory Of Biodiversity ◽  
Amazonian Forests

Theoretical studies of ecosystem models have generally concluded that large numbers of species will not stably coexist if the species are all competing for the same limited set of resources. Here, we describe a simple multi-trait model of competition where the presence of N resources will lead to the stable coexistence of up to 2 N species. Our model also predicts that the long-term dynamics of the population will lie on a neutral attractor hyperplane. When the population shifts within the hyperplane, its dynamics will behave neutrally, while shifts which occur perpendicular to the hyperplane will be subject to restoring forces. This provides a potential explanation of why complex ecosystems might exhibit both niche-like and neutral responses to perturbations. Like the neutral theory of biodiversity, our model generates good fits to species abundance distributions in several datasets but does so without needing to evoke inter-generational stochastic effects, continuous species creation or immigration dynamics. Additionally, our model is able to explain species abundance correlations between independent but similar ecosystems separated by more than 1400 km inside the Amazonian forests.

scholarly journals Structural basis for a complex I mutation that blocks pathological ROS production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhan Yin ◽  
Nils Burger ◽  
Duvaraka Kula-Alwar ◽  
Dunja Aksentijević ◽  
Hannah R. Bridges ◽  
...  
Keyword(s):  
Point Mutation ◽  
Complex I ◽  
Structural Changes ◽  
Ischemia Reperfusion ◽  
Single Point ◽  
Structural Basis ◽  
Single Point Mutation ◽  
Ros Production

AbstractMitochondrial complex I is central to the pathological reactive oxygen species (ROS) production that underlies cardiac ischemia–reperfusion (IR) injury. ND6-P25L mice are homoplasmic for a disease-causing mtDNA point mutation encoding the P25L substitution in the ND6 subunit of complex I. The cryo-EM structure of ND6-P25L complex I revealed subtle structural changes that facilitate rapid conversion to the “deactive” state, usually formed only after prolonged inactivity. Despite its tendency to adopt the “deactive” state, the mutant complex is fully active for NADH oxidation, but cannot generate ROS by reverse electron transfer (RET). ND6-P25L mitochondria function normally, except for their lack of RET ROS production, and ND6-P25L mice are protected against cardiac IR injury in vivo. Thus, this single point mutation in complex I, which does not affect oxidative phosphorylation but renders the complex unable to catalyse RET, demonstrates the pathological role of ROS production by RET during IR injury.

scholarly journals CRISPR/Cas9-mediated mutation revealed cytoplasmic tail is dispensable for IZUMO1 function and male fertility

Reproduction ◽  
2016 ◽  
Vol 152 (6) ◽  
pp. 665-672 ◽  
Author(s):  
Samantha A M Young ◽  
Haruhiko Miyata ◽  
Yuhkoh Satouh ◽  
Masanaga Muto ◽  
Martin R Larsen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Male Fertility ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Cytoplasmic Tail ◽  
Binding Partner ◽  
C Terminus ◽  
Manipulation System

IZUMO1 is a protein found in the head of spermatozoa that has been identified as essential for sperm–egg fusion. Its binding partner in the egg has been discovered (JUNO); however, the roles of several domains within IZUMO1 remain unexplored. One such domain is the C-terminus, which undergoes major phosphorylation changes in the cytoplasmic portion of the protein during rat epididymal transit. However, the cytoplasmic tail of IZUMO1 in many species is highly variable, ranging from 55 to one amino acid. Therefore, to understand the role of the cytoplasmic tail of IZUMO1 in mouse, we utilised the gene manipulation system of CRISPR/Cas9 to generate a point mutation resulting in a premature stop codon, producing mice with truncated IZUMO1. Mice without the cytoplasmic tail of IZUMO1 showed normal fertility but decreased the amount of protein, indicating that whilst this region is important for the expression level of IZUMO1, it is dispensable for fertilisation in the mouse.

Sign in / Sign up

Export Citation Format

Share Document