Geographic Patterns In Pollen Production In The Plant Ring Species Euphorbia tithymaloides In The Caribbean

2020 ◽  
Vol 45 (4) ◽  
pp. 845-853
Author(s):  
N. Ivalú Cacho ◽  
Daniel José-Zacatula
Keyword(s):  
Floral Morphology ◽  
Pollen Production ◽  
Geographic Pattern ◽  
Male Function ◽  
Inflorescence Morphology ◽  
Geographic Patterns ◽  
The Caribbean ◽  
Alternative Scenarios ◽  
Ring Species ◽  
Ovule Production

Abstract—We examine investment in male function in the context of geography and floral morphology in the plant ring species Euphorbia tithymaloides, which colonized the Caribbean from Mexico/Guatemala along two fronts that roughly correspond to the Greater and the Lesser Antilles and that meet in the vicinity of the Anegada Passage. Our results on investment in pollen relative to ovule production are consistent with E. tithymaloides relying on pollinators for reproduction across its range in the Caribbean. We document a geographic pattern of reduction in anther number and pollen:ovule ratios in populations of E. tithymaloides towards the Anegada Passage, which is consistent with a possible geographic transition towards a mixed breeding system where selfing has increased importance in this area where its two expansion fronts meet. The reduction in pollen production is correlated with inflorescence morphology, which converges to relatively shorter cyathia towards the Anegada Passage along both fronts. We discuss alternative scenarios and potential drivers of the patterns we document.

scholarly journals Convergent evolution in floral morphology in a plant ring species, the Caribbean Euphorbia tithymaloides

2019 ◽  
Vol 106 (7) ◽  
pp. 1032-1045 ◽  
Author(s):  
N. Ivalú Cacho ◽  
María José Monteverde‐Suárez ◽  
Patrick J. McIntyre
Keyword(s):  
Convergent Evolution ◽  
Floral Morphology ◽  
The Caribbean ◽  
Ring Species

A Molecular Phylogeny for the Genus Coccoloba (Polygonaceae) with an Assessment of Biogeographic Patterns

2020 ◽  
Vol 45 (3) ◽  
pp. 567-575
Author(s):  
Daniel Mark Koenemann ◽  
Janelle M. Burke
Keyword(s):  
Molecular Phylogeny ◽  
New World ◽  
South American ◽  
Geographic Pattern ◽  
South American Species ◽  
Crown Group ◽  
Biogeographic Patterns ◽  
Geographic Patterns ◽  
The Caribbean ◽  
Migration Event

Abstract—Species in the genus Coccoloba are trees, shrubs, and lianas present in low elevation tropical and sub-tropical forests. Since 1756, well over 400 taxa have been described for Coccoloba. Coccoloba species are natively distributed throughout the New World in a variety of habitats. Despite being distributed throughout the Neotropics, the concentration of Coccoloba species in a given area varies considerably, with four centers of diversity for the genus: southern and coastal Brazil, the West Indies, Mesoamerica, and Amazonia. We here present the first molecular phylogeny of Coccoloba and use this phylogeny to investigate geographic patterns of diversity within the genus. The topology of the phylogeny and the closest related genera to Coccoloba suggest a Mesoamerican origin for the genus. The South American species are recovered as the crown group of the phylogeny with one instance of a separate migration event from Mesoamerica to South America. Coccoloba species in Mesoamerica and the Caribbean show little to no geographic pattern to their diversification. Mesoamerica and the Caribbean are best considered as one phytogeographic region for Coccoloba.

Enhancing the Process of Knowledge Discovery in Geographic Databases Using Geo-Ontologies

2009 ◽  
pp. 2405-2426 ◽  
Author(s):  
Vania Bogorny ◽  
Paulo Martins Engel ◽  
Luis Otavio Alavares
Keyword(s):  
Knowledge Discovery ◽  
Prior Knowledge ◽  
Association Rules ◽  
Pattern Mining ◽  
Spatial Association ◽  
Geographic Pattern ◽  
Geographic Patterns ◽  
Geographic Databases ◽  
Novel Approach ◽  
Amount Of Knowledge

This chapter introduces the problem of mining frequent geographic patterns and spatial association rules from geographic databases. In the geographic domain most discovered patterns are trivial, non-novel, and noninteresting, which simply represent natural geographic associations intrinsic to geographic data. A large amount of natural geographic associations are explicitly represented in geographic database schemas and geo-ontologies, which have not been used so far in frequent geographic pattern mining. Therefore, this chapter presents a novel approach to extract patterns from geographic databases using geoontologies as prior knowledge. The main goal of this chapter is to show how the large amount of knowledge represented in geo-ontologies can be used to avoid the extraction of patterns that are previously known as noninteresting.

Comparative Development of Some Taxonomically Critical Floral Inflorescence Features in Cyperaceae

1991 ◽  
Vol 39 (2) ◽  
pp. 119 ◽  
Author(s):  
JJ Bruhl
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Developmental Stages ◽  
Floral Morphology ◽  
Developmental Studies ◽  
Comparative Development ◽  
Inflorescence Morphology ◽  
The Family ◽  
Scanning Electron

Morphology at different developmental stages was investigated by dissection and by scanning electron microscopy (SEM) in five sedges: Eleocharis (three species) and Schoenoplectus (both Cyperoideae, Scirpeae), and Lepidosperma (Caricoideae, Schoeneae). In each case all the perianth segments (scales or bristles) were positioned outside the staminal primordia or stamens, consistent with classical interpretations of flowers. Putative exceptions and previous alternative interpretations of floral morphology in the Cyperaceae are discussed. SEM developmental studies of Hypolytreae (e.g. Scirpodendron) are needed for further clarification of interpretative floral/inflorescence morphology in the family.

scholarly journals Geographic patterns of vertebrate diversity and identification of relevant areas for conservation in Europe

2012 ◽  
Vol 35 (1) ◽  
pp. 1-11
Author(s):  
M. J. T. Assunção–Albuquerque ◽  
◽  
J. M. Rey Benayas ◽  
M. Á. Rodriguez ◽  
F. S. Albuquerque ◽  
...  
Keyword(s):  
Influence Factors ◽  
Biodiversity Loss ◽  
Geographic Pattern ◽  
Human Influence ◽  
Conservation Policies ◽  
Terrestrial Vertebrate ◽  
Geographic Patterns ◽  
Biodiversity Decline ◽  
Variance Explained ◽  
The Eu

The ‘EU Council conclusions on biodiversity post–2010’ re–enforced Europe’s commitment to halt biodiversity loss by 2020. Identifying areas of high–value for biodiversity conservation is an important issue to meet this target. We investigated the geographic pattern of terrestrial vertebrate diversity status in Europe by assessing the species richness, rarity, vulnerability (according to IUCN criteria), and a combined index of the three former for the amphibians, reptiles, bird and mammals of this region. We also correlated the value of all indices with climate and human influence variables. Overall, clear geographic gradients of species diversity were found. The combined biodiversity index indicated that high–value biodiversity areas were mostly located in the Mediterranean basin and the highest vulnerability was found in the Iberian peninsula for most taxa. Across all indexes, the proportion of variance explained by climate and human influence factors was moderate to low. The results obtained in this study have the potential to provide valuable support for nature conservation policies in Europe and, consequently, might contribute to mitigate biodiversity decline in this region.

Enhancing the Process of Knowledge Discovery in Geographic Databases Using Geo-Ontologies

2011 ◽  
pp. 160-181 ◽  
Author(s):  
Vania Bogorny ◽  
Paulo Martins Engel ◽  
Luis Otavio Alavares
Keyword(s):  
Knowledge Discovery ◽  
Prior Knowledge ◽  
Association Rules ◽  
Pattern Mining ◽  
Spatial Association ◽  
Geographic Pattern ◽  
Geographic Patterns ◽  
Geographic Databases ◽  
Novel Approach ◽  
Amount Of Knowledge

This chapter introduces the problem of mining frequent geographic patterns and spatial association rules from geographic databases. In the geographic domain most discovered patterns are trivial, non-novel, and non-interesting, which simply represent natural geographic associations intrinsic to geographic data. A large amount of natural geographic associations are explicitly represented in geographic database schemas and geo-ontologies, which have not been used so far in frequent geographic pattern mining. Therefore, this chapter presents a novel approach to extract patterns from geographic databases using geo-ontologies as prior knowledge. The main goal of this chapter is to show how the large amount of knowledge represented in geo-ontologies can be used to avoid the extraction of patterns that are previously known as non-interesting.

Natural Enemies Drive Geographic Variation in Plant Defenses

Science ◽  
2012 ◽  
Vol 338 (6103) ◽  
pp. 116-119 ◽  
Author(s):  
Tobias Züst ◽  
Christian Heichinger ◽  
Ueli Grossniklaus ◽  
Richard Harrington ◽  
Daniel J. Kliebenstein ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Natural Enemies ◽  
Field Data ◽  
Causal Link ◽  
Selection Experiment ◽  
Strongly Correlated ◽  
Geographic Pattern ◽  
Geographic Patterns ◽  
Selective Forces ◽  
Aphid Abundance

Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources of Arabidopsis thaliana, coupled with 39 years of field data on aphid abundance, to (i) demonstrate that geographic patterns in a polymorphic defense locus (GS-ELONG) are strongly correlated with changes in the relative abundance of two specialist aphids; and (ii) demonstrate differential selection by the two aphids on GS-ELONG, using a multigeneration selection experiment. We thereby show a causal link between variation in abundance of the two specialist aphids and the geographic pattern at GS-ELONG, which highlights the potency of natural enemies as selective forces.

scholarly journals The Caribbean slipper spurge Euphorbia tithymaloides : the first example of a ring species in plants

2012 ◽  
Vol 279 (1742) ◽  
pp. 3377-3383 ◽  
Author(s):  
N. Ivalú Cacho ◽  
David A. Baum
Keyword(s):  
Species Complex ◽  
Phylogenetic Analyses ◽  
Nuclear Gene ◽  
Distinct Species ◽  
Virgin Islands ◽  
Greater Antilles ◽  
Species Integrity ◽  
The Caribbean ◽  
Northern South America ◽  
Ring Species

A ring species arises when a parental population expands around an area of unsuitable habitat in such a way that when the two fronts meet they behave as distinct species while still being connected through a series of intergrading populations. Ring species offer great possibilities for studying the forces causing species divergence (e.g. the nature of pre-zygotic or post-zygotic reproductive isolation) or helping to maintain species integrity (e.g. reinforcement). Yet, ring species are extremely rare, and have only been documented convincingly in animals. Here, we present phylogenetic analyses of two nuclear gene regions from the Caribbean slipper spurge ( Euphorbia tithymaloides ) species complex that provide evidence that this group forms a ring species. These data show that the species complex originated in the area where Mexico and Guatemala meet, and expanded around the Caribbean basin along two distinct fronts: one eastward through the Yucatan Peninsula and into the Greater Antilles (GA); one southeastward through northern South America and then northward to the Lesser Antilles and eastern GA. The two terminal forms co-occur in the Virgin Islands and appear to be morphologically and ecologically distinct. Thus, our results suggest that Euphorbia tithymaloides is the first compelling example of a ring species in plants.

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