Measuring Evolutionary Constraints: A Markov Model for Phylogenetic Transitions among Seed Dispersal Syndromes

Evolution ◽  
1992 ◽  
Vol 46 (1) ◽  
pp. 136 ◽  
Author(s):  
Charles H. Janson
Keyword(s):  
Seed Dispersal ◽  
Markov Model ◽  
Evolutionary Constraints ◽  
Dispersal Syndromes ◽  
Seed Dispersal Syndromes

scholarly journals A numerical analysis of Ephedra L. based on reproductive features

2013 ◽  
Vol 20 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Yong Yang
Keyword(s):  
Numerical Analysis ◽  
Seed Dispersal ◽  
Endemic Species ◽  
Reproductive Organs ◽  
Old World ◽  
Geographic Ranges ◽  
Dispersal Syndromes ◽  
Plant Taxon ◽  
Seed Dispersal Syndromes

A numerical analysis of Ephedra L. was conducted based on 29 characters of reproductive organs. The results indicate that species are not grouped according to their geographic ranges, sect. Alatae is in one group, sect. Asarca excluding E. cutleri and E. viridis consists of a Eu-asarca group while sect. Ephedra plus E. cutleri and E. viridis of the traditional sect. Asarca make up a third expanded Ephedra group. The Old World sect. Monospermae including E. rhytidosperma, E. equisetina, E. nebrodensis, E. monosperma and E. procera was rediscovered in this study while those Himalayan endemic species (e.g. E. minuta, E. likiangensis, E. saxatilis, E. dawuensis and E. gerardiana) used to be grouped in the Old World sect. Monospermae are clustered together with sect. Scandentes including E. foeminea, E. ciliata, E. altissima and E. fragilis. This study further confirms that the adaptive seed dispersal syndromes of sect. Asarca have originated for not only once. Some new features are introduced as related to dispersal, e.g. weight and size of seeds, and nature and thickness of the outer envelope.DOI: http://dx.doi.org/10.3329/bjpt.v20i1.15464Bangladesh J. Plant Taxon. 20(1): 51-60, 2013 (June) 

scholarly journals PATTERNS OF SEED DISPERSAL SYNDROMES AT DIFFERENT ALTITUDES IN THE SEMIARID REGION

FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1751
Author(s):  
Wedson Batista dos Santos ◽  
Luiz Carlos Marangon ◽  
Fernando José Freire ◽  
Rafael Leite Braz ◽  
José Edson De Lima Torres ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Woody Plants ◽  
Semiarid Region ◽  
Forest Fragments ◽  
Sampling Area ◽  
Dispersal Patterns ◽  
Breast Height ◽  
Dispersal Syndromes ◽  
Seed Dispersal Syndromes ◽  
Altitude Level

The objective of this study was to assess the patterns of seed dispersal syndromes of woody plants from nine forest fragments distributed at different altitude levels on the Araripe plateau, in Pernambuco, Brazil. For data collection, we divided the altitudes within the region into three categories: lower level (altitudes ≤600 m); intermediate level (600< altitudes <750 m); and higher level (altitudes ≥750 m). We registered nine fragments, three per altitude level. In each of them, we distributed 20 rectangular sampling units with 250 m², totaling a sampling area of 4.5 ha. We quantified, collected, and identified woody plants with a diameter at breast height higher than or equal to 0.1 m (DBH 1.30 m ≥0.10 m). We characterized the dispersal syndrome according to the characteristics of the fruits and seeds and based on a literature review. In the whole region, we sampled 6,987 individuals, distributed in 35 families, 82 genera, and 153 species. Approximately 41% of all individuals are dispersed by animals, 37% by the plant’s own mechanisms, and 21% by the wind. In terms of dispersal, 47% of species were classified as zoochorous, 23% as autochorous, and 14% as anemochorous. Seed dispersal patterns vary according to altitude levels, with higher regions tending to present greater representativeness of biotic dispersers and lower ones, abiotic.

scholarly journals Life-forms, pollination and seed dispersal syndromes in plant communities on ironstone outcrops, SE Brazil

2011 ◽  
Vol 25 (2) ◽  
pp. 395-412 ◽  
Author(s):  
Claudia Maria Jacobi ◽  
Flávio Fonseca do Carmo
Keyword(s):  
Seed Dispersal ◽  
Life Form ◽  
Life Forms ◽  
Climatic Conditions ◽  
Pollination Syndrome ◽  
Rock Outcrops ◽  
Dispersal Syndromes ◽  
Se Brazil ◽  
Seed Dispersal Syndromes ◽  
Forest Islands

Rock outcrops play an important role in enhancing plant diversity in montane ecosystems. Ironstone outcrops (cangas) are among the lithotypes less known and most threatened in SE Brazil, due to mining activities. Besides species composition, a key feature to promote their conservation and restoration is the knowledge of the community prevalent life-forms, pollination and seed dispersal syndromes. The analyses were done based on published floristic surveys of cangas in SE Brazil. A total of 353 species of angiosperms (70 families) were assigned to one of the two predominant physiognomies (open areas and forest islands) on ironstone outcrops. Sixteen families responded for 70% of all species. Compared to Raunkiaer's spectrum, phanerophytes were over- and therophytes were under-represented. Phanerophytes were the predominant life-form in forest islands, while hemicryptophytes were outstanding in open areas. Entomophily was the dominant pollination syndrome in both habitats. Zoochory was dominant in forest islands and ranked last in open areas, where anemochory and autochory prevailed. Considering that both forest islands and open areas are subjected to the same climatic conditions, the results corroborate the influence of geoedaphic components in the three traits analysed.

scholarly journals The sugar composition of fruits in the diet of spider monkeys (Ateles geoffroyi) in tropical humid forest in Costa Rica

2003 ◽  
Vol 19 (6) ◽  
pp. 709-716 ◽  
Author(s):  
Pablo Riba-Hernández ◽  
Kathryn E. Stoner ◽  
Peter W. Lucas
Keyword(s):  
Costa Rica ◽  
Seed Dispersal ◽  
Soluble Carbohydrates ◽  
Ateles Geoffroyi ◽  
Spider Monkeys ◽  
Sugar Composition ◽  
Humid Forest ◽  
Dispersal Syndromes ◽  
Seed Dispersal Syndromes ◽  
Selection Of

Spider monkeys (Ateles geoffroyi) detect sucrose at a threshold lower than any primate yet tested and prefer sucrose to glucose or fructose in laboratory tests. This preferential selection of sucrose led to the hypothesis that such acute discrimination is related to a diet of sucrose-rich fruits. Furthermore, it has been suggested that fruit sugars may be related to distinct guilds of vertebrate seed-dispersers. The objectives of this study were: (1) to test if spider monkeys select sucrose-rich fruits both within and among plant species and (2) to test the hypothesis that sugar concentration is related to bird, bat or monkey seed-dispersal syndromes. Data were collected from one troop of spider monkeys in south-western Costa Rica. Interspecific comparison of ingested fruits shows that spider monkeys consumed species with significantly higher concentrations of glucose and fructose than sucrose. Similarly, at the intraspecific level, food-fruits had significantly more fructose and glucose than non-food fruits, but no difference was found for sucrose. The three different sugar types were not correlated with the importance of the species in the diet based on the amount of time they spent consuming each species. Although sucrose concentrations were significantly higher in primate-dispersed species compared with those dispersed by other vertebrates, soluble carbohydrates in primate-dispersed fruits were principally composed of glucose and fructose. Neither fructose nor glucose concentrations showed significant differences across the three categories of seed dispersal.

scholarly journals How to approach the study of syndromes in macroevolution

2021 ◽  
Author(s):  
Miranda Sinnott-Armstrong ◽  
Rocio Deanna ◽  
Chelsea Pretz ◽  
Jesse Harris ◽  
Amy Dunbar-Wallis ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Recent Work ◽  
Continuous Variation ◽  
Biased Sampling ◽  
Multiple Traits ◽  
Trait Variation ◽  
Central Concept ◽  
Dispersal Syndromes ◽  
Seed Dispersal Syndromes ◽  
Sampling Approach

Syndromes, wherein multiple traits evolve convergently in response to a shared selective driver, form a central concept in ecology and evolution. Recent work has questioned the utility and indeed the existence of some of the classic syndromes, such as pollination and seed dispersal syndromes. Here, we discuss some of the major issues that have plagued research into syndromes in macroevolution. First, observation of co-evolving traits (sometimes called “trait syndromes'') is often used as evidence of adaptation to a particular driver, even when the link between traits and adaptation is not well-tested. Second, the study of syndromes often uses a biased sampling approach, focusing on the most extreme examples, which may obscure significant continuous variation between traits. Finally, researchers often focus on the traits that are easiest to measure even though these may not be the most directly relevant to adaptive hypotheses. We argue that these issues can be avoided by combining macroevolutionary studies of trait variation across entire clades with explicit tests of adaptive hypotheses, and that taking this approach will lead to a better understanding of syndrome-like evolution and its drivers.

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