scholarly journals Insights on long-distance dispersal, ecological and morphological evolution in the fern genus Microgramma from phylogenetic inferences

2020 ◽  
Author(s):  
Thaís Elias Almeida ◽  
Alexandre Salino ◽  
Jean-Yves Dubuisson ◽  
Sabine Hennequin
Keyword(s):  
Phylogenetic Relationships ◽  
Morphological Evolution ◽  
Divergence Times ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
African Species ◽  
Infrageneric Classification ◽  
History Of ◽  
Epiphytic Fern

AbstractThe epiphytic fern genus Microgramma (Polypodiaceae) comprises 30 species occurring mainly in the Neotropics with one species in Africa, being an example of trans-Atlantic disjunction. Morphologically and ecologically, Microgramma presents a wide variation that is not seen in its closest related genera. Recent works changed the circumscription of Microgramma to better conform with phylogenetic evidence, but no comprehensively sampled study has addressed the evolution of this lineage. This study aimed to investigate phylogenetic relationships, ecological and morphological evolution within Microgramma, as well as test the role of long-distant dispersal in the history of the genus. Sequences from five plastid regions were used to infer the phylogenetic relationships and estimate divergence times. Our results show five clades in Microgramma that do not corroborate any infrageneric classification system proposed. Several morphological traits seem to be homoplastic, such as leaf dimorphism. Tuber-like myrmecodomatia are suggested to be synapomorphic for one clade, although ant-plant association appears in two distinct lineages. Microgramma lycopodioides and M. mauritiana are not closely related, with the African species nested within an Atlantic Forest clade, indicating a long-distance dispersal event estimated to have occurred around 15 Ma from South America to Africa, followed by speciation.

scholarly journals The role of mucilage envelope in the endozoochory of selected plant taxa

2020 ◽  
Vol 108 (1) ◽  
Author(s):  
A. Kreitschitz ◽  
E. Haase ◽  
S. N. Gorb
Keyword(s):  
Digestive System ◽  
Columba Livia ◽  
Local Scale ◽  
Ocimum Basilicum ◽  
Long Distance Dispersal ◽  
Morphological Adaptation ◽  
Long Distance ◽  
Germination Ability ◽  
First Time

AbstractMyxodiaspory (formation of mucilage envelope around seeds and fruits) is a common adaptation to dry habitats known in many families of Angiosperms. The mucilage envelope of some seeds seems to be also a unique morphological adaptation which protects myxospermatic diaspores while passing through the bird’s digestive system. To evaluate the protective potential of mucilage, we fed the diaspores of seven plant species (representing three different mucilage types and three species of non-mucilaginous plants) to pigeons, Columba livia domestica. Twenty-four hours later, we collected the droppings of pigeons and examined a total of 18,900 non-destroyed diaspores to check for mucilage presence and germination ability. Out of all the examined diaspores, 4.5% were mucilaginous seeds. Among them, the highest number (12.2–13.5%) of viable diaspores belonged to the hemicellulosic type of mucilage (from Plantago species). Only 3.7% of germinating diaspores with pectic mucilage (Linum usitatissimum) were collected, and no seeds representing cellulosic mucilage (e.g., Ocimum basilicum). For non-mucilaginous plants, we collected only a few individual seeds (0.1% out of 8100 seeds used). We noted that the mucilaginous seeds found in the droppings were able to germinate; however, the germination ability was generally smaller in comparison to the control (i.e., not digested) seeds. Our results revealed that the presence of mucilage envelope has an impact on diaspore dispersal and survivability. With our experiments, we demonstrated for the first time that the mucilage envelope, especially of the non-cellulosic type, supports endozoochory. We also showed that non-mucilaginous seeds can be occasionally dispersed via endozoochory and are able to germinate. The results of our studies can explain the ways of plants distribution at a small, local scale as well as in long-distance dispersal, e.g., between islands or even continents.

The evolutionary history of Nothofagus (Nothofagaceae)

1993 ◽  
Vol 6 (2) ◽  
pp. 111 ◽  
Author(s):  
RS Hill ◽  
GJ Jordan
Keyword(s):  
Parallel Evolution ◽  
Cladistic Analysis ◽  
Long Distance ◽  
Interesting Insight ◽  
Extant Species ◽  
Singular Event ◽  
History Of ◽  
Morphological Differences ◽  
The Relationship

A cladistic analysis of Nothofagus is presented. Comparison of potential outgroups (Fagus and Betulaceae) suggests that Fagus is most satisfactory, but clear morphological differences between it and Nothofagus support the placement of the latter in the monogeneric family Nothofagaceae. The cladistic analysis supports the four subgenera and four extant pollen groups proposed in the most recent revisions and is consistent with the extensive fossil record, although not especially supported by it. The evolution of the deciduous or evergreen habit. so long considered a singular event of importance in Nothofagus, probably occurred several times, and is an example of parallel evolution. Resolution within subgenera is not high in most cases, but subgenus Lophozonia offers a particularly interesting insight into the relationship among extant species and the role of rare long distance dispersal across significant ocean barriers in Nothofagus biogeography. More data are required to refine the phylogeny.

scholarly journals Influence of gut morphology on passive transport of freshwater bryozoans by waterfowl in Doñana (southwestern Spain)

2004 ◽  
Vol 82 (6) ◽  
pp. 835-840 ◽  
Author(s):  
Jordi Figuerola ◽  
Andy J Green ◽  
Katrina Black ◽  
Beth Okamura
Keyword(s):  
Aquatic Invertebrates ◽  
Bird Species ◽  
Passage Time ◽  
Passive Dispersal ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Active Dispersal ◽  
Intestine Length ◽  
Internal Transport

Waterbirds have been proposed as important vectors for the passive dispersal of those aquatic invertebrates and plants that lack a capacity for active dispersal between isolated water bodies. We analysed the frequency of internal transport of bryozoan propagules (statoblasts) by waterbirds in Doñana, Spain, by examining their presence in the intestines and ceca of dead birds and analysing the role of different aspects of gut characteristics in explaining variation in the presence/absence and abundance of statoblasts. Of the 228 samples examined, 7.9% presented intact statoblasts of Plumatella fungosa (Pallas, 1768), Plumatella emarginata Allman, 1844, and two unidentified Plumatella species. For a given bird species, individuals with heavier gizzards and shorter ceca had a lower incidence and abundance of statoblasts in the lower gut. Grit mass and intestine length were unrelated to the presence or abundance of statoblasts. Our results suggest that waterbirds frequently transport bryozoans on a local scale, with lighter gizzards and longer ceca favouring such transport. Lighter gizzards are likely to destroy fewer propagules before they reach the lower gut. Species and individuals with longer ceca are particularly good candidates for long-distance dispersal of bryozoans, given the longer passage time of propagules that enter the ceca.

scholarly journals Enigmatic clusters of sandstone boulders on plateaus of the Stołowe Mountains (Sudetes, south-west Poland) – their geoheritage and geotouristic value

Geologos ◽  
2021 ◽  
Vol 27 (3) ◽  
pp. 141-155
Author(s):  
Piotr Migoń ◽  
Krzysztof Parzóch
Keyword(s):  
Late Cretaceous ◽  
Sedimentary Rocks ◽  
Long Distance ◽  
Long Distance Transport ◽  
South West ◽  
History Of ◽  
Clastic Sedimentary ◽  
Distance Transport ◽  
Plateau Level

Abstract Among sites of geomorphological interest in the tableland of the Stołowe Mountains, consisting of clastic sedimentary rocks of Late Cretaceous age, are enigmatic occurrences and clusters of sandstone boulders within plateau levels that are underlain by mudstones and marls. These boulders are allochthonous, having been derived from the quartz sandstone beds that support the upper plateau level and stratigraphically are in excess of 50 m above the altitudinal position of the boulders. Topographic conditions preclude long-distance transport from the escarpment slopes; boulders are hypothesised to be the last remnants of completely degraded outliers (mesas) of the upper plateau. Their present-day altitudinal position is explained by passive ‘settling’ following disintegration of caprock and denudation of the underlying weaker rocks. Two localities are here presented in detail, Łężyckie Skałki and Pustelnik, along with adjacent boulder trains in the valleys incised into the plateau. It is argued that both localities have considerable geoheritage value and both play the role of geosites, although on-site facilities are so far limited. However, the complex history of boulders sets a series of challenges for successful geo-interpretation.

scholarly journals An Evolutionary Study of Carex Subg. Psyllophorae (Cyperaceae) Sheds Light on a Strikingly Disjunct Distribution in the Southern Hemisphere, With Emphasis on Its Patagonian Diversification

2021 ◽  
Vol 12 ◽  
Author(s):  
Carmen Benítez-Benítez ◽  
Ana Otero ◽  
Kerry A. Ford ◽  
Pablo García-Moro ◽  
Sabina Donadío ◽  
...  
Keyword(s):  
General Pattern ◽  
Disjunct Distribution ◽  
Divergence Times ◽  
Species Number ◽  
Primary Role ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Diversification Rates ◽  
Sw Pacific ◽  
Western Palearctic

Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared to most Carex lineages, and its remarkable disjunct distribution in four continents corresponding to three independent sections: sect. Psyllophorae in Western Palearctic, sect. Schoenoxiphium in Afrotropical region, and sect. Junciformes in South America (SA) and SW Pacific. The latter section is mainly distributed in Patagonia and the Andes, where it is one of the few Carex groups with a significant in situ diversification. We assess the role of historical geo-climatic events in the evolutionary history of the group, particularly intercontinental colonization events and diversification processes, with an emphasis on SA. We performed an integrative study using phylogenetic (four DNA regions), divergence times, diversification rates, biogeographic reconstruction, and bioclimatic niche evolution analyses. The crown age of subg. Psyllophorae (early Miocene) supports this lineage as one of the oldest within Carex. The diversification rate probably decreased over time in the whole subgenus. Geography seems to have played a primary role in the diversification of subg. Psyllophorae. Inferred divergence times imply a diversification scenario away from primary Gondwanan vicariance hypotheses and suggest long-distance dispersal-mediated allopatric diversification. Section Junciformes remained in Northern Patagonia since its divergence until Plio-Pleistocene glaciations. Andean orogeny appears to have acted as a northward corridor, which contrasts with the general pattern of North-to-South migration for temperate-adapted organisms. A striking niche conservatism characterizes the evolution of this section. Colonization of the SW Pacific took place on a single long-distance dispersal event from SA. The little ecological changes involved in the trans-Pacific disjunction imply the preadaptation of the group prior to the colonization of the SW Pacific. The high species number of the section results from simple accumulation of morphological changes (disparification), rather than shifts in ecological niche related to increased diversification rates (radiation).

scholarly journals Evidence of avian-mediated long distance dispersal in American tardigrades

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5035 ◽  
Author(s):  
Matthew J. Mogle ◽  
Scott A. Kimball ◽  
William R. Miller ◽  
Richard D. McKown
Keyword(s):  
Bird Species ◽  
Distribution Patterns ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Neotropical Migrant ◽  
Grus Canadensis ◽  
Sandhill Crane ◽  
Migrant Birds ◽  
North And South

Terrestrial tardigrades, commonly known as “water bears”, are part of a phylum of microscopic, aquatic invertebrates famous for cryptobiosis and space travel, but little is known about their modes of dispersal on Earth. Wind is assumed, but not truly demonstrated, to be the major method of global dispersal. Yet, some water bear distribution patterns cannot be explained by patterns of prevailing winds. Mammals and birds have been proposed as potential animal vectors. Importantly, most nearctic-neotropical migrant birds move north and south, with many crossing the equator, whereas prevailing winds move west to east or east to west but do not cross the equator. When multiplied by billions of birds over tens of millions of years, if the ectozoochory of tardigrades by birds is true then both regional and intercontinental patterns can be better explained. To test for the potential role of birds in tardigrade dispersal, the nests of 10 species for birds were examined. Seventy percent of nests were positive for tardigrades, demonstrating that some birds are in a position for transference. The carcasses of eight birds (six species) found dead from window strikes and a Sandhill Crane (Grus canadensis) found dead during routine surveys were also examined. Of the birds examined, 66% yielded tardigrades from two classes, three orders, and five species, including juveniles, adults, and eggs, suggesting that many bird species are potential vectors for many species of tardigrades. Our data support the hypothesis of avian-mediated long distance dispersal of tardigrades and provide evidence that further investigation is warranted.

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