scholarly journals Ancestry and evolution of seasonal migration in the Parulidae

2011 ◽  
Vol 279 (1728) ◽  
pp. 610-618 ◽  
Author(s):  
Benjamin M. Winger ◽  
Irby J. Lovette ◽  
David W. Winkler
Keyword(s):  
Phylogenetic Signal ◽  
Rapid Change ◽  
Large Family ◽  
Seasonal Migration ◽  
Ancestral State ◽  
Migratory Behaviour ◽  
Wood Warbler ◽  
Wood Warblers ◽  
History Of ◽  
The Tropics

Seasonal migration in birds is known to be highly labile and subject to rapid change in response to selection, such that researchers have hypothesized that phylogenetic relationships should neither predict nor constrain the migratory behaviour of a species. Many theories on the evolution of bird migration assume a framework that extant migratory species have evolved repeatedly and relatively recently from sedentary tropical or subtropical ancestors. We performed ancestral state reconstructions of migratory behaviour using a comprehensive, well-supported phylogeny of the Parulidae (the ‘wood-warblers’), a large family of Neotropical and Nearctic migratory and sedentary songbirds, and examined the rates of gain and loss of migration throughout the Parulidae. Counter to traditional hypotheses, our results suggest that the ancestral wood-warbler was migratory and that losses of migration have been at least as prevalent as gains throughout the history of Parulidae. Therefore, extant sedentary tropical radiations in the Parulidae represent losses of latitudinal migration and colonization of the tropics from temperate regions. We also tested for phylogenetic signal in migratory behaviour, and our results indicate that although migratory behaviour is variable within some wood-warbler species and clades, phylogeny significantly predicts the migratory distance of species in the Parulidae.

scholarly journals The evolutionary history of Stomatopoda (Crustacea: Malacostraca) inferred from molecular data

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3844 ◽  
Author(s):  
Cara Van Der Wal ◽  
Shane T. Ahyong ◽  
Simon Y.W. Ho ◽  
Nathan Lo
Keyword(s):  
Phylogenetic Analyses ◽  
Sister Group ◽  
Molecular Data ◽  
Recent Common Ancestor ◽  
Ancestral State ◽  
Crown Group ◽  
Most Recent Common Ancestor ◽  
History Of ◽  
The Tropics ◽  
Age Constraints

The crustacean order Stomatopoda comprises seven superfamilies of mantis shrimps, found in coastal waters of the tropics and subtropics. These marine carnivores bear notable raptorial appendages for smashing or spearing prey. We investigated the evolutionary relationships among stomatopods using phylogenetic analyses of three mitochondrial and two nuclear markers. Our analyses recovered the superfamily Gonodactyloidea as polyphyletic, withHemisquillaas the sister group to all other extant stomatopods. A relaxed molecular clock, calibrated by seven fossil-based age constraints, was used to date the origin and major diversification events of stomatopods. Our estimates suggest that crown-group stomatopods (Unipeltata) diverged from their closest crustacean relatives about 340 Ma (95% CRI [401–313 Ma]). We found that the specialized smashing appendage arose after the spearing appendage ∼126 Ma (95% CRI [174–87 Ma]). Ancestral state reconstructions revealed that the most recent common ancestor of extant stomatopods had eyes with six midband rows of hexagonal ommatidia. Hexagonal ommatidia are interpreted as plesiomorphic in stomatopods, and this is consistent with the malacostracan ground-plan. Our study provides insight into the evolutionary timescale and systematics of Stomatopoda, although further work is required to resolve with confidence the phylogenetic relationships among its superfamilies.

scholarly journals Settling down of seasonal migrants promotes bird diversification

2014 ◽  
Vol 281 (1784) ◽  
pp. 20140473 ◽  
Author(s):  
Jonathan Rolland ◽  
Frédéric Jiguet ◽  
Knud Andreas Jønsson ◽  
Fabien L. Condamine ◽  
Hélène Morlon
Keyword(s):  
Species Richness ◽  
Sedentary Behaviour ◽  
Evolutionary History ◽  
Seasonal Migration ◽  
Migratory Behaviour ◽  
Migratory Species ◽  
Diversification Rates ◽  
Extinction Rates ◽  
History Of ◽  
Daughter Species

How seasonal migration originated and impacted diversification in birds remains largely unknown. Although migratory behaviour is likely to affect bird diversification, previous studies have not detected any effect. Here, we infer ancestral migratory behaviour and the effect of seasonal migration on speciation and extinction dynamics using a complete bird tree of life. Our analyses infer that sedentary behaviour is ancestral, and that migratory behaviour evolved independently multiple times during the evolutionary history of birds. Speciation of a sedentary species into two sedentary daughter species is more frequent than speciation of a migratory species into two migratory daughter species. However, migratory species often diversify by generating a sedentary daughter species in addition to the ancestral migratory one. This leads to an overall higher migratory speciation rate. Migratory species also experience lower extinction rates. Hence, although migratory species represent a minority (18.5%) of all extant birds, they have a higher net diversification rate than sedentary species. These results suggest that the evolution of seasonal migration in birds has facilitated diversification through the divergence of migratory subpopulations that become sedentary, and illustrate asymmetrical diversification as a mechanism by which diversification rates are decoupled from species richness.

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

Systematics, Biogeography, and Morphological Character Evolution of the Hemiepiphytic Subfamily Monsteroideae (Araceae)

2019 ◽  
Vol 104 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Alejandro Zuluaga ◽  
Martin Llano ◽  
Ken Cameron
Keyword(s):  
Dna Sequences ◽  
Pacific Islands ◽  
R Package ◽  
Morphological Characters ◽  
Ancestral State ◽  
Seed Shape ◽  
Long Distance ◽  
The Pacific ◽  
And Migration ◽  
The Tropics

The subfamily Monsteroideae (Araceae) is the third richest clade in the family, with ca. 369 described species and ca. 700 estimated. It comprises mostly hemiepiphytic or epiphytic plants restricted to the tropics, with three intercontinental disjunctions. Using a dataset representing all 12 genera in Monsteroideae (126 taxa), and five plastid and two nuclear markers, we studied the systematics and historical biogeography of the group. We found high support for the monophyly of the three major clades (Spathiphylleae sister to Heteropsis Kunth and Rhaphidophora Hassk. clades), and for six of the genera within Monsteroideae. However, we found low rates of variation in the DNA sequences used and a lack of molecular markers suitable for species-level phylogenies in the group. We also performed ancestral state reconstruction of some morphological characters traditionally used for genera delimitation. Only seed shape and size, number of seeds, number of locules, and presence of endosperm showed utility in the classification of genera in Monsteroideae. We estimated ancestral ranges using a dispersal-extinction-cladogenesis model as implemented in the R package BioGeoBEARS and found evidence for a Gondwanan origin of the clade. One tropical disjunction (Monstera Adans. sister to Amydrium Schott–Epipremnum Schott) was found to be the product of a previous Boreotropical distribution. Two other disjunctions are more recent and likely due to long-distance dispersal: Spathiphyllum Schott (with Holochlamys Engl. nested within) represents a dispersal from South America to the Pacific Islands in Southeast Asia, and Rhaphidophora represents a dispersal from Asia to Africa. Future studies based on stronger phylogenetic reconstructions and complete morphological datasets are needed to explore the details of speciation and migration within and among areas in Asia.

A fossil record of land plant origins from charophyte algae

Science ◽  
2021 ◽  
Vol 373 (6556) ◽  
pp. 792-796 ◽  
Author(s):  
Paul K. Strother ◽  
Clinton Foster
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Phylogenetic Signal ◽  
Land Plant ◽  
Fossil Plants ◽  
Fossil Plant ◽  
Molecular Phylogenetic ◽  
History Of ◽  
Time Gap ◽  
Evolutionary Continuity

Molecular time trees indicating that embryophytes originated around 500 million years ago (Ma) during the Cambrian are at odds with the record of fossil plants, which first appear in the mid-Silurian almost 80 million years later. This time gap has been attributed to a missing fossil plant record, but that attribution belies the case for fossil spores. Here, we describe a Tremadocian (Early Ordovician, about 480 Ma) assemblage with elements of both Cambrian and younger embryophyte spores that provides a new level of evolutionary continuity between embryophytes and their algal ancestors. This finding suggests that the molecular phylogenetic signal retains a latent evolutionary history of the acquisition of the embryophytic developmental genome, a history that perhaps began during Ediacaran-Cambrian time but was not completed until the mid-Silurian (about 430 Ma).

Architecture Culture, Humanitarian Expertise:

2017 ◽  
Vol 76 (3) ◽  
pp. 367-384 ◽  
Author(s):  
Anooradha Iyer Siddiqi
Keyword(s):  
Professional Practice ◽  
Building Design ◽  
Joint Activity ◽  
Joint Construction ◽  
Mutual Interest ◽  
History Of ◽  
History Of Architecture ◽  
Anchor Points ◽  
The Tropics ◽  
Shared Mission

Architecture Culture, Humanitarian Expertise: From the Tropics to Shelter, 1953–93 recovers a history of architecture and humanitarianism through an examination of institutions and the development of a subfield of professional practice. Charting mutual interest between major humanitarian agencies and the architecture and planning professions, Anooradha Iyer Siddiqi maps the joint construction of expertise, tying together three sets of concerns: preoccupations with the tropics and climate as anchor points for the science and rationalization behind building design, the institutionalization of humanitarian spatial expertise in the academy and industry, and a tension between models for development and for relief. This joint activity and its discursive themes, from the “tropics” to “shelter”—whether aggrandizing or instrumentalizing the shared mission of architecture and humanitarianism—raised the stakes for architectural expertise as a driver for practice as well as history.

scholarly journals The Evolutionary History of the Chymase Locus -a Locus Encoding Several of the Major Hematopoietic Serine Proteases

2021 ◽  
Vol 22 (20) ◽  
pp. 10975
Author(s):  
Srinivas Akula ◽  
Zhirong Fu ◽  
Sara Wernersson ◽  
Lars Hellman
Keyword(s):  
Mast Cell ◽  
T Cell ◽  
Serine Proteases ◽  
Phylogenetic Trees ◽  
Granzyme B ◽  
Large Family ◽  
Cathepsin G ◽  
Immune Functions ◽  
New Class ◽  
History Of

Several hematopoietic cells of the immune system store large amounts of proteases in cytoplasmic granules. The absolute majority of these proteases belong to the large family of chymotrypsin-related serine proteases. The chymase locus is one of four loci encoding these granule-associated serine proteases in mammals. The chymase locus encodes only four genes in primates, (1) the gene for a mast-cell-specific chymotryptic enzyme, the chymase; (2) a T-cell-expressed asp-ase, granzyme B; (3) a neutrophil-expressed chymotryptic enzyme, cathepsin G; and (4) a T-cell-expressed chymotryptic enzyme named granzyme H. Interestingly, this locus has experienced a number of quite dramatic expansions during mammalian evolution. This is illustrated by the very large number of functional protease genes found in the chymase locus of mice (15 genes) and rats (18 genes). A separate expansion has also occurred in ruminants, where we find a new class of protease genes, the duodenases, which are expressed in the intestinal region. In contrast, the opossum has only two functional genes in this locus, the mast cell (MC) chymase and granzyme B. This low number of genes may be the result of an inversion, which may have hindered unequal crossing over, a mechanism which may have been a major factor in the expansion within the rodent lineage. The chymase locus can be traced back to early tetrapods as genes that cluster with the mammalian genes in phylogenetic trees can be found in frogs, alligators and turtles, but appear to have been lost in birds. We here present the collected data concerning the evolution of this rapidly evolving locus, and how these changes in gene numbers and specificities may have affected the immune functions in the various tetrapod species.

scholarly journals Relationship Between Changes in Activity and Plantar Ulcer Recurrence in a Patient With Diabetes Mellitus

2005 ◽  
Vol 85 (6) ◽  
pp. 579-588 ◽  
Author(s):  
Donovan J Lott ◽  
Katrina S Maluf ◽  
David R Sinacore ◽  
Michael J Mueller
Keyword(s):  
Diabetes Mellitus ◽  
Plantar Pressure ◽  
Weight Bearing ◽  
Rapid Change ◽  
Activity Level ◽  
Ulcer Recurrence ◽  
Sudden Increase ◽  
Average Value ◽  
Plantar Ulcer ◽  
History Of

Abstract Background and Purpose. Although pressure-reducing interventions have been effective in the healing of neuropathic foot ulcers, these ulcers frequently recur in people with diabetes mellitus (DM). This case report illustrates how sudden changes in weight-bearing activity may have affected ulcer recurrence in a patient with DM and how the physical stress theory (PST) relates to ulcer recurrence for this patient. Case Description. The patient was a 66-year-old man with a history of DM, peripheral neuropathy, and recurrent plantar ulcers. His plantar ulcer healed after total contact casting. Outcome. Despite relatively low peak plantar pressure (9.3 N/cm2), the patient's ulcer recurred within 4 weeks of healing. Plantar pressure assessment and activity monitoring suggested that a rapid and sudden increase in weight-bearing activity (steps per day) contributed to cumulative plantar tissue stress that was 3.3 times higher on the day of ulcer recurrence than his average value. Although his cumulative plantar stress was high compared with his usual value, the cumulative value was similar to the amount of daily stress of individuals without a history of recurrent ulcers. Discussion. Within the context of the PST, rapid change in activity level may have an effect on cumulative stress and the risk of ulcer recurrence.

scholarly journals The Barbados Cloud Observatory: Anchoring Investigations of Clouds and Circulation on the Edge of the ITCZ

2016 ◽  
Vol 97 (5) ◽  
pp. 787-801 ◽  
Author(s):  
Bjorn Stevens ◽  
David Farrell ◽  
Lutz Hirsch ◽  
Friedhelm Jansen ◽  
Louise Nuijens ◽  
...  
Keyword(s):  
Climate Change ◽  
Deep Convection ◽  
Seasonal Migration ◽  
Saharan Dust ◽  
Boreal Summer ◽  
Max Planck ◽  
Research Aircraft ◽  
Meteorological Impact ◽  
The Tropics ◽  
The Relationship

Abstract Clouds over the ocean, particularly throughout the tropics, are poorly understood and drive much of the uncertainty in model-based projections of climate change. In early 2010, the Max Planck Institute for Meteorology and the Caribbean Institute for Meteorology and Hydrology established the Barbados Cloud Observatory (BCO) on the windward edge of Barbados. At 13°N the BCO samples the seasonal migration of the intertropical convergence zone (ITCZ), from the well-developed winter trades dominated by shallow cumulus to the transition to deep convection as the ITCZ migrates northward during boreal summer. The BCO is also well situated to observe the remote meteorological impact of Saharan dust and biomass burning. In its first six years of operation, and through complementary intensive observing periods using the German High Altitude and Long Range Research Aircraft (HALO), the BCO has become a cornerstone of efforts to understand the relationship between cloudiness, circulation, and climate change.

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