scholarly journals A reassessment of Mappia (Icacinaceae) taxonomy using environmental data

2020 ◽  
pp. e1716
Author(s):  
Rodrigo Duno de Stefano ◽  
Israel Loera ◽  
Diego Francisco Angulo

Background and Aims: Mappia (Icacinaceae) is a genus comprising four species inhabiting Mesoamerica and the Greater Antilles. In the most recent phylogenetic analysis based on morphological data, three species, representing a continental clade (Mappia longipes, M. mexicana and M. multiflora) sister to the Antillean species M. racemosa, were supported. Our aims in this study were to evaluate whether environmental data support the previous hypothesis in Mappia entities. Methods: In this study, we use ecological niche analysis (environmental niche modeling and niche divergence/conservatism tests) and multivariate analysis of variance (MANOVA) to test the previous morphological hypothesis at species and infraspecific level.   Key results: Ecological differentiation between M. multiflora distributed from southeast Mexico to Costa Rica and M. racemosa occurring in Cuba, Jamaica, and Puerto Rico (Greater Antilles) was found, but not between the infraspecific taxa within the Antilles (M. racemosa var. brachycarpa, and M. racemosa var. racemosa). Conclusions: Our study brings an important signal of the ecological divergence between closely related species, but with disjunct patterns of distribution.

Mammalia ◽  
2020 ◽  
Vol 84 (4) ◽  
pp. 392-406
Author(s):  
Sameer B. Bajaru ◽  
Aparna Lajmi ◽  
Ranjit Manakadan ◽  
Amol R. Kulavmode ◽  
Uma Ramakrishnan

AbstractKondana soft-furred rat is a critically endangered (CR) species, known from a single locality – Sinhgad in the northern Western Ghats, India. However, the taxonomic status of this species is uncertain due to its close resemblance to the widely distributed soft-furred field rat Millardia meltada, which has serious implications on the conservation status of Millardia kondana. In this study, we assessed the current taxonomic status of M. kondana through an integrative approach combining morphological, molecular and environmental niche modeling analyses. We collected morphological data from the specimens around Sinhgad as well as preserved specimens in the museum. Both morphological and two-dimensional (2D) morphometrical analyses showed a significant difference between M. kondana and M. meltada. Molecular phylogeny based on cytochrome b gene revealed a sister relationship between M. kondana and M. meltada, and both species form distinct well-supported monophyletic clades. Niche modeling also predicted niche segregation between the two species: M. kondana preferred areas with a high elevation and precipitation seasonality while M. meltada favored regions with a low elevation and precipitation. We confirmed that M. kondana is taxonomically distinct from M. meltada, and based on our estimates of its occurrence and occupancy, M. kondana continues to be treated as CR until further detailed investigations.


2019 ◽  
Vol 124 (3) ◽  
pp. 411-422 ◽  
Author(s):  
James S Borrell ◽  
Ghudaina Al Issaey ◽  
Darach A Lupton ◽  
Thomas Starnes ◽  
Abdulrahman Al Hinai ◽  
...  

AbstractBackground and AimsSouthern Arabia is a global biodiversity hotspot with a high proportion of endemic desert-adapted plants. Here we examine evidence for a Pleistocene climate refugium in the southern Central Desert of Oman, and its role in driving biogeographical patterns of endemism.MethodsDistribution data for seven narrow-range endemic plants were collected systematically across 195 quadrats, together with incidental and historic records. Important environmental variables relevant to arid coastal areas, including night-time fog and cloud cover, were developed for the study area. Environmental niche models using presence/absence data were built and tuned for each species, and spatial overlap was examined.Key ResultsA region of the Jiddat Al Arkad reported independent high model suitability for all species. Examination of environmental data across southern Oman indicates that the Jiddat Al Arkad displays a regionally unique climate with higher intra-annual stability, due in part to the influence of the southern monsoon. Despite this, the relative importance of environmental variables was highly differentiated among species, suggesting that characteristic variables such as coastal fog are not major cross-species predictors at this scale.ConclusionsThe co-occurrence of a high number of endemic study species within a narrow monsoon-influenced region is indicative of a refugium with low climate change velocity. Combined with climate analysis, our findings provide strong evidence for a southern Arabian Pleistocene refugium in Oman’s Central Desert. We suggest that this refugium has acted as an isolated temperate and mesic island in the desert, resulting in the evolution of these narrow-range endemic flora. Based on the composition of species, this system may represent the northernmost remnant of a continuous belt of mesic vegetation formerly ranging from Africa to Asia, with close links to the flora of East Africa. This has significant implications for future conservation of endemic plants in an arid biodiversity hotspot.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kamil Konowalik ◽  
Agata Nosol

AbstractWe examine how different datasets, including georeferenced hardcopy maps of different extents and georeferenced herbarium specimens (spanning the range from 100 to 85,000 km2) influence ecological niche modeling. We check 13 of the available environmental niche modeling algorithms, using 30 metrics to score their validity and evaluate which are useful for the selection of the best model. The validation is made using an independent dataset comprised of presences and absences collected in a range-wide field survey of Carpathian endemic plant Leucanthemum rotundifolium (Compositae). Our analysis of models’ predictive performances indicates that almost all datasets may be used for the construction of a species distributional range. Both very local and very general datasets can produce useful predictions, which may be more detailed than the original ranges. Results also highlight the possibility of using the data from manually georeferenced archival sources in reconstructions aimed at establishing species’ ecological niches. We discuss possible applications of those data and associated problems. For the evaluation of models, we suggest employing AUC, MAE, and Bias. We show an example of how AUC and MAE may be combined to select the model with the best performance.


2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Adrián Fuentes-Luque ◽  
Pabsi Livmar González-Irizarry

Even though Audiovisual Translation (AVT) is growing and flourishing throughout the world, it is practically unheard-of in the Caribbean, where accessibility faces an even bleaker existence. The circumstances of the deaf and hard of hearing (also referred to as D/deaf) are no less alarming: social barriers and exclusion are widespread. This paper emphasizes the need to make subtitles accessible in the Spanish-speaking Caribbean, specifically on the islands of Puerto Rico, Cuba, and the Dominican Republic, and underscores the challenges faced by the D/deaf communities on each island. Our research focuses on issues like AVT laws and regulations, the habits of viewers of audiovisual (AV) products, and literacy and limitations on each island. This paper also examines the different types of D/deaf audiovisual consumers in the Spanish-speaking Caribbean and the difficulties each community faces when accessing media and entertainment. Our research reveals the current state of AVT accessibility in this region and provides a foundation for influencing legislators to begin enforcing AVT regulations and drafting SDH guidelines.


1969 ◽  
Vol 25 (4) ◽  
pp. 51-55
Author(s):  
Melville T. Cook

During the summer of 1936 Mr. L. R. Holdridge of the U. S. Forestry Service called my attention to germination failures of Magnolia portoricensis Bello. This and the very closely related species M. splendens Urban produce exceptionally fine woods but unfortunately both species are being exterminated very rapidly. Both species were very abundant at one time but at the present, it is practically impossible to find young trees in the forest. The Forestry Station has been trying to overcome his difficulty by sowing seeds in seed beds and growing seedlings for transplanting. Up to the present only one seedling of M. borinquensis has been produced although thousands of seeds have been sown.


Botany ◽  
2011 ◽  
Vol 89 (3) ◽  
pp. 191-201
Author(s):  
Jennifer DeWoody ◽  
John D. Nason ◽  
Marian Smith

Boltonia decurrens (Torr. & A. Gray) A. Wood is a federally threatened herb endemic to the Illinois River floodplain, and currently restricted to fewer than 25 populations. We tested for hybridization between this species and a widespread congener, Boltonia asteroides (L.) L’Hér., at two sites where they are known to occur in sympatry, by comparing morphological and genetic diversity with an allopatric population of each species. Morphological analyses identified significant differentiation between species. Discriminant classification analysis of the morphological data assigned most individuals to one or the other of the two parental species with high probability (>0.95), with only four plants having an intermediate probability of assignment (<0.90) indicative of hybrid origin. Similarly, likelihood-based methods based on genetic marker data (allozymes) failed to detect the presence of F1 hybrids in either sympatric population and revealed only low frequencies of F2 and backcross progeny. These findings demonstrate that combining morphological and genetic data increases the likelihood of detecting low-scale introgression between closely related species. Even with this combined approach, the low rate of recombination between these species together with their limited sympatry indicate that hybridization does not pose an immediate threat to the genetic integrity of B. decurrens.


2020 ◽  
Vol 16 (4) ◽  
pp. 20190947 ◽  
Author(s):  
David C. Blackburn ◽  
Rachel M. Keeffe ◽  
María C. Vallejo-Pareja ◽  
Jorge Vélez-Juarbe

The nearly 200 species of direct-developing frogs in the genus Eleutherodactylus (the Caribbean landfrogs, which include the coquís) comprise an important lineage for understanding the evolution and historical biogeography of the Caribbean. Time-calibrated molecular phylogenies provide indirect evidence for the processes that shaped the modern anuran fauna, but there is little direct evidence from the fossil record of Caribbean frogs about their distributions in the past. We report a distal humerus of a frog from the Oligocene (approx. 29 Ma) of Puerto Rico that represents the earliest known fossil frog from any Caribbean island. Based on its prominent rounded distal humeral head, distally projecting entepicondyle, and reduced ectepicondyle, we refer it to the genus Eleutherodactylus . This fossil provides additional support for an early arrival of some groups of terrestrial vertebrates to the Greater Antilles and corroborates previous estimates based on molecular phylogenies suggesting that this diverse Caribbean lineage was present in the islands by the mid-Cenozoic.


2019 ◽  
Vol 127 (2) ◽  
pp. 479-492 ◽  
Author(s):  
Anna E Hiller ◽  
Michelle S Koo ◽  
Kari R Goodman ◽  
Kerry L Shaw ◽  
Patrick M O’Grady ◽  
...  

Abstract The role of the environmental niche in fostering ecological divergence during adaptive radiation remains enigmatic. In this study, we examine the interplay between environmental niche divergence and conservatism in the context of adaptive radiation on oceanic islands, by characterizing the niche breadth of four Hawaiian arthropod radiations: Tetragnatha spiders (Tetragnathidae Latreille, 1804), Laupala crickets (Gryllidae Otte, 1994), a clade of Drosophila flies (Drosophilidae Fallén, 1823) and Nesosydne planthoppers (Delphacidae Kirkaldy, 1907). We assembled occurrence datasets for the four lineages, modelled their distributions and quantified niche overlap. All four groups occupy the islands in distinct ways, highlighting the contrasting axes of diversification for different lineages. Laupala and Nesosydne have opposite environmental niche extents (broad and narrow, respectively), whereas Tetragnatha and Drosophila share relatively intermediate tolerances. Temperature constrains the distributions of all four radiations. Tests of phylogenetic signal suggest that, for Tetragnatha and Drosophila, closely related species exhibit similar environmental niches; thus, diversification is associated with niche conservatism. Sister species comparisons also show that populations often retain similar environmental tolerances, although exceptions do occur. Results imply that diversification does not occur through ecological speciation; instead, adaptive radiation occurs largely within a single environment.


2008 ◽  
Vol 19 (1) ◽  
pp. 47-63 ◽  
Author(s):  
Reniel Rodríguez Ramos ◽  
Elvis Babilonia ◽  
L. Antonio Curet ◽  
Jorge Ulloa

Pottery in contexts that predate the entrance of Arawak societies to the Antilles (500 B.C.) by at least one millennium demand a reassessment of the introduction of this technology to the islands. We summarize the available evidence of what we term the Pre-Arawak Pottery horizon and address the social implications of the introduction of such technology to the insular Caribbean, based on the role of pots as tools. We show that this early pottery is more widespread than originally thought, extending from Cuba to Hispanola and perhaps to Puerto Rico and the Lesser Antilles as well. We argue that the paucity of early ceramic contexts discovered thus far could have resulted from the consideration of pottery as intrusive in Pre-Arawak contexts and because of its technological and stylistic overlap with wares associated to the Ostionoid series (A.D. 600-1500) of the Greater Antilles. Based on this evidence, we conclude by suggesting that some of the post-Saladoid manifestations that have been identified in the islands could have resulted from a multifocal development of these pre-Arawak cultures rather than simply from the divergent evolution of Saladoid societies as has been argued thus far.


Sign in / Sign up

Export Citation Format

Share Document