scholarly journals No evidence for parallel evolution of cursorial limb adaptations among Neogene South American native ungulates (SANUs)

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256371
Author(s):  
Darin A. Croft ◽  
Malena Lorente
Keyword(s):  
South America ◽  
North American ◽  
Parallel Evolution ◽  
South American ◽  
Late Oligocene ◽  
Pronounced Increase ◽  
Genus Level ◽  
Strong Trend ◽  
Selective Forces ◽  
America South

During the Neogene, many North American ungulates evolved longer limbs. Presumably, this allowed them to move more efficiently or quickly in open habitats, which became more common during this interval. Evidence suggests that open habitats appeared even earlier in South America, but no study to date has investigated whether the ungulate-like mammals of South America (South American native ungulates or SANUs) evolved similar limb adaptations. We analyzed limb elongation in the two predominant SANU groups, notoungulates and litopterns, by compiling genus-level occurrences from the late Oligocene to the Pleistocene and calculating metatarsal/femur ratio (Mt:F). None of the groups or subgroups we analyzed show a pronounced increase in Mt:F across this interval, with the possible exception of proterotheriid litopterns. Proterotheriids are thought to have inhabited forested environments rather than open ones, which raises questions about the selective forces responsible for limb elongation in ungulates. Conversely, notoungulates, which are traditionally thought to have lived in open habitats, show no strong trend of increasing Mt:F across this interval. Our study suggests that the macroevolutionary trend of limb elongation in ungulate-like mammals is not universal and is highly influenced by the evolutionary affinities of the groups being analyzed.

A morphometric evaluation of the subspecies of Fragaria chiloensis

1998 ◽  
Vol 76 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Paul M Catling ◽  
Sue Porebski
Keyword(s):  
Discriminant Analysis ◽  
South America ◽  
North American ◽  
The Other ◽  
South American ◽  
Taxonomic Rank ◽  
Fragaria Chiloensis ◽  
America South ◽  
The Relationship ◽  
Morphometric Evaluation

To evaluate the relationship between the four subspecies of Fragaria chiloensis, 14 characters were measured in 95 plants. F ratios from ANOVA were used to determine and apply the optimal characters for subspecies separation. Discriminant analysis indicated that the Hawaiian ssp. sandwicensis was entirely distinct, differing from the other subspecies in having longer leaflets and longer hairs on the undersurface of the leaflets and more numerous leaflet veins. The South American and North American plants were significantly different but overlapped to a degree. The former differed primarily by having mostly 6-10 petals, instead of having 5-6 (rarely 7) petals. The two North American subspecies overlapped extensively and may be best transferred to a lower taxonomic rank. A key to the subspecies is included.Key words: Fragaria chiloensis, ssp. pacifica, ssp. lucida, ssp.sandwicensis, ssp. chiloensis, Rosaceae, strawberry, taxonomy, classification, morphology, North America, South America, Hawaii.

New and unusual host records for North American and South American spider wasps (Hymenoptera: Pompilidae)

Zootaxa ◽  
2020 ◽  
Vol 4891 (1) ◽  
pp. 1-112
Author(s):  
FRANK E. KURCZEWSKI ◽  
RICK C. WEST ◽  
CECILIA WAICHERT ◽  
KELLY C. KISSANE ◽  
DARRELL UBICK ◽  
...  
Keyword(s):  
United States ◽  
South America ◽  
Central America ◽  
North American ◽  
Western Hemisphere ◽  
South American ◽  
New Host ◽  
United States Mexico ◽  
First Time ◽  
Taxonomic Order

New and unusual host records for 133 species and subspecies of Pompilidae predominantly from the southwestern United States, Mexico, Central America, and South America are presented in modified taxonomic order. First-time species host records are given for Calopompilus Ashmead, Pepsis Fabricius, Hemipepsis Dahlbom, Priocnessus Banks, Entypus Dahlbom, Pompilocalus Roig-Alsina, Sphictostethus Kohl, Auplopus Spinola, Ageniella Banks, Eragenia Banks, Aporus Spinola, Poecilopompilus Ashmead, Tachypompilus Ashmead, Anoplius Dufour, Priochilus (Fabricius) and Notocyphus Smith. New host spider families are introduced for Calopompilus, Pepsis, Hemipepsis, Priocnessus, Entypus, Cryptocheilus Panzer, Priocnemis Schiødte, Auplopus, Ageniella, Eragenia, Aporus, Tachypompilus, Anoplius, Priochilus and Notocyphus. Eight host spider families are reported from the Western Hemisphere for the first time: Halonoproctidae (Notocyphus dorsalis dorsalis Cresson); Dipluridae (Pepsis pretiosa Dahlbom, P. montezuma Smith, P. infuscate Spinola, P. atripennis Fabricius, P. martini Vardy, Priocnessus vancei Waichert and Pitts); Nemesiidae (Pepsis pallidolimbata Lucas, P. viridis Lepeletier, P. spp., Pompilocalus hirticeps (Guérin), Sphictostethus gravesii (Haliday), S. striatulus Roig-Alsina, Priocnemis oregona Banks); Barychelidae (Eragenia sp.); Paratropididae (Pepsis stella Montet); Trechaleidae (Hemipepsis toussainti (Banks), Entypus unifasciatus cressoni (Banks), Tachypompilus ferrugineus (Say), Tachypompilus unicolor cerinus Evans, Priochilus gloriosum (Cresson); Desidae (Ageniella accepta (Cresson), Sphictostethus isodontus Roig-Alsina) and Selenopidae (Priochilus scrupulum (Fox), Tachypompilus erubescens (Taschenberg) or xanthopterus (Rohwer)). The first known host records for the rare South American pompilid genera Chirodamus (Lycosidae: Lycosa sp.) and Herbstellus (Nemesiidae: Diplothelopsis cf bonariensis Mello-Leitão) are presented. 

Geographic Variation in Fluted Projectile Points: A Hemispheric Perspective

1999 ◽  
Vol 64 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Juliet E. Morrow ◽  
Toby A. Morrow
Keyword(s):  
North America ◽  
South America ◽  
Geographic Variation ◽  
Great Plains ◽  
North American ◽  
South American ◽  
Western North America ◽  
Radiocarbon Dates ◽  
Projectile Points ◽  
Fluted Points

This paper examines geographic variation in fluted point morphology across North and South America. Metric data on 449 North American points, 31 Central American points, and 61 South American points were entered into a database. Ratios calculated from these metric attributes are used to quantify aspects of point shape across the two continents. The results of this analysis indicate gradual, progressive changes in fluted point outline shape from the Great Plains of western North America into adjacent parts of North America as well as into Central and South America. The South American “Fishtail” form of fluted point is seen as the culmination of incremental changes in point shape that began well into North America. A geographically gradual decline in fluting frequency also is consistent with the stylistic evolution of the stemmed “Fishtail” points. Although few in number, the available radiocarbon dates do suggest that “Fishtail” fluted points in southern South America are younger than the earliest dates associated with Clovis points in western North America. All of these data converge on the conclusion that South American “Fishtail” points evolved from North American fluted points.

Iterative evolution of hypercarnivory in canids (Mammalia: Carnivora): evolutionary interactions among sympatric predators

Paleobiology ◽  
1991 ◽  
Vol 17 (4) ◽  
pp. 340-362 ◽  
Author(s):  
Blaire Van Valkenburgh
Keyword(s):  
South America ◽  
North American ◽  
Morphological Evolution ◽  
Late Oligocene ◽  
The North ◽  
Rapid Diversification ◽  
Competition For Food ◽  
Pattern Of Specialization ◽  
Iterative Evolution ◽  
Length Reduction

Convergent evolution of hypercarnivorous adaptations in canids has occurred a number of times in the last 40 m.y. among distantly related taxa. The adaptations include an increase in carnassial blade length, reduction or loss of post-carnassial molars, and transformation of the talonid of the lower first molar from a basinlike depression into a trenchant, bladelike cusp. Although the diversity of these specialized canids is typically low in past and present communities, it was unusually high during the Late Oligocene of North America and the Pleistocene of South America. These two comparable events provide an opportunity for exploring possible causes of the evolution of hypercarnivory in canids. Plots of generic diversity against time for North American predators reveal a roughly inverse relationship between the number of hypercarnivorous canid taxa and the numbers of other hypercarnivores, such as creodonts, nimravids, mustelids, and amphicyonids. Similarly, the radiation of hypercarnivorous canids in South America occurred at a time of relatively low diversity of other hypercarnivores. Analysis of trophic diversity within the North American carnivore paleoguild before, during, and after the Late Oligocene reveals considerable taxonomic turnover among carnivores because of immigration and speciation. Late Oligocene hypercarnivorous canids appear to have been replaced first by amphicyonids and large mustelids, and then by felids.Despite the repeated tendency of canids to evolve adaptations for hypercarnivory, a canid has yet to appear that is completely catlike, that is, without any post-carnassial molars. This possible constraint on morphological evolution in canids is argued to have resulted, paradoxically, in increased flexibility over evolutionary time and a great potential for rapid diversification and clade survivorship. Finally, it is suggested that the iterative pattern of specialization of the lower molars for meat-slicing that is seen in all families of carnivores, past and present, is probably a result of intraspecific competition for food, perhaps among littermates. This intraspecific selective force is countered by competition among species, since there are limits on the number of sympatric hypercarnivorous species within a single community.

scholarly journals A Single Chromosome Unexpectedly Links Highly Divergent Isolates of Toxoplasma gondii

mBio ◽  
2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Katelyn A. Walzer ◽  
Jon P. Boyle
Keyword(s):  
Toxoplasma Gondii ◽  
South America ◽  
North American ◽  
Phylogenetic Analyses ◽  
Unexpected Finding ◽  
Type I ◽  
South American ◽  
Single Chromosome ◽  
Content Type ◽  
The North

ABSTRACT Toxoplasma gondii is an obligate intracellular parasite that can cause disease in all warm-blooded animals studied to date, including humans. Over a billion people have been infected with this parasite worldwide. In Europe and North America, Toxoplasma has a clonal population structure, where only three lineages are highly dominant (strain types I, II, and III). Khan et al. [mBio 2(6): e00228-11, 2011] have carried out phylogenetic analyses on a large number of diverse strains from outside of these lineages and found evidence for a significant split between the clonal North American/European lineages and those in South America. In contrast to most of the genome, nearly all North American/European strains sampled, and the majority of South American strains sampled, harbored at least portions of a monomorphic chromosome Ia (Ia*). In contrast to previous models, these data suggest that the monomorphic haplotype originated in South America and migrated to the North. These authors propose that South American haplotype 12 was a precursor to modern-day type II, while South American haplotypes 6 and 9 crossed with haplotype 12 to give rise to the type I and III lineages, respectively. However, the findings reported by Khan et al. complicate the origin of chromosome Ia, since there are members of haplotypes 9 and 12 with nearly complete versions of Ia* and members of haplotypes 6 and 12 with over 50% of Ia*. This unexpected finding raises exciting new questions about how an entire common chromosome can be found within strains that are highly divergent at most other genomic loci.

Understanding the limits of assessing sustainability at Universidad San Francisco de Quito USFQ, Ecuador, while reporting for a North American system

2018 ◽  
Vol 19 (4) ◽  
pp. 721-738 ◽  
Author(s):  
Alexandra Velasco ◽  
Melanie Valencia ◽  
Samantha Morrow ◽  
Valeria Ochoa-Herrera
Keyword(s):  
South America ◽  
San Francisco ◽  
North American ◽  
Evaluation System ◽  
Geographical Location ◽  
Rating System ◽  
South American ◽  
Content Type ◽  
American University ◽  
American System

Purpose Universidad San Francisco de Quito, USFQ, completed an assessment study to understand its performance in sustainability in 2012. This study aims to recognize the limitations of applying a North American rating system considering relevant criteria to a South American university and to emphasize the importance and lack of benchmarks available in the region. Design/methodology/approach Methodology used for this study is based on the Sustainability Tracking Assessment Rating System (STARS) by AASHE. In December 2013, USFQ joined the Pilot Program that included publicly documenting efforts, sharing feedback and making suggestions for system improvements. Findings Data collected by USFQ in 2012 and 2013 illustrate how the status of USFQ as a non-residential, teaching university in Ecuador in a developing country had several challenges while using an evaluation system established for universities within a North American system. The limits of assessing sustainability in South America are associated to its geographical location, the number of students and staff that commute to University and the lack of environmental services and certifications available in Ecuador. There are applicability issues with the use of STARS without performance reports from regional peers that can guide the development of relevant benchmarks for future comparability. Originality/value Little research has been conducted in the assessment and tracking of sustainability within universities in South America. This paper is one of the first to address the applicability of a North American self-reporting tool to a South American university.

scholarly journals Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America

2016 ◽  
Vol 12 (4) ◽  
pp. 20160062 ◽  
Author(s):  
Kieren J. Mitchell ◽  
Sarah C. Bray ◽  
Pere Bover ◽  
Leopoldo Soibelzon ◽  
Blaine W. Schubert ◽  
...  
Keyword(s):  
South America ◽  
North American ◽  
Convergent Evolution ◽  
Phylogenetic Analyses ◽  
Early Pleistocene ◽  
South American ◽  
The North ◽  
Molecular Phylogenetic ◽  
North And South America ◽  
North And South

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear ( Tremarctos ornatus ), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears ( Tremarctos ), South American short-faced bears ( Arctotherium ) and North American short-faced bears ( Arctodus ) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears ( Arctodus and Arctotherium ), potentially as an adaptation to dominate competition for megafaunal carcasses.

scholarly journals Can north american fish passage tools work for South american migratory fishes?

2007 ◽  
Vol 5 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Claudio Rafael Mariano Baigún ◽  
John Michael Nestler ◽  
Norberto Oscar Oldani ◽  
R. Andrew Goodwin ◽  
Larry J. Weber
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
South America ◽  
North American ◽  
Fish Passage ◽  
Fish Movement ◽  
South American ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Tracking Model

In North America, the Numerical Fish Surrogate (NFS) is used to design fish bypass systems for emigrating juvenile salmon as they migrate from hatchery outfalls and rearing habitats to adult habitat in the oceans. The NFS is constructed of three linked modules: 1) a computational fluid dynamics model describes the complex flow fields upstream of dams at a scale sufficiently resolved to analyze, understand and forecast fish movement, 2) a particle tracking model interpolates hydraulic information from the fixed nodes of the computational fluid model mesh to multiple locations relevant to migrating fish, and 3) a behavior model simulates the cognition and behavior of individual fish in response to the fluid dynamics predicted by the computational fluid dynamics model. These three modules together create a virtual reality where virtual fish exhibit realistic dam approach behaviors and can be counted at dam exits in ways similar to the real world. Once calibrated and validated with measured fish movement and passage data, the NFS can accurately predict fish passage proportions with sufficient precision to allow engineers to select one optimum alternative from among many competing structural or operational bypass alternatives. Although South American fish species are different from North American species, it is likely that the basic computational architecture and numerical methods of the NFS can be used for fish conservation in South America. Consequently, the extensive investment made in the creation of the NFS need not be duplicated in South America. However, its use in South America will require that the behavioral response of the continent's unique fishes to hydrodynamic cues must be described, codified and tested before the NFS can be used to conserve fishes by helping design efficient South American bypass systems. To this end, we identify studies that could be used to describe the movement behavior of South American fishes of sufficient detail that they could be used to develop, calibrate and validate a South American version of the NFS.

Mitochondrial DNA suggests cryptic speciation in Prodiplosis longifila Gagné (Diptera: Cecidomyiidae) associated with geographic distance and host specialization

2018 ◽  
Vol 108 (6) ◽  
pp. 739-749 ◽  
Author(s):  
D.N. Duque-Gamboa ◽  
M.F. Castillo-Cárdenas ◽  
L.M. Hernández ◽  
Y.C. Guzmán ◽  
M.R. Manzano ◽  
...  
Keyword(s):  
South America ◽  
Genetic Differentiation ◽  
North American ◽  
Population Analysis ◽  
Geographic Distance ◽  
Sweet Pepper ◽  
Host Specialization ◽  
South American ◽  
The North ◽  
Wide Range

AbstractProdiplosis longifila is reported as a pest of a wide range of species cultivated in America, including citrus, solanaceous species and asparagus. This species has different behavioural traits that are primarily centred on the oviposition habit and the feeding of larvae, which can change depending on the host. However, scarce information is available on population studies and the natural history of this insect, and uncertainty exists about the taxonomic identity and the geographic distribution of this species. The main objective was to perform a phylogenetic and genetic study of P. longifila populations and to define whether the North American and South American populations belong to the same species or whether a differentiation process had occurred due to geographic distance. A second objective was to determine whether this species showed genetic differentiation by host specialization in South America. The phylogenetic and population analyses based on DNA barcodes (cytochrome oxidase I gene) and a region of the ribosomal DNA (ITS2) revealed divergent clades attributable to geographic distance and host specificity. The North American and South American P. longifila insects were confirmed to be genetically distinct, and the genetic distances exceeded the values expected for intraspecific variation. In South America, the population analysis of P. longifila from tomato, sweet pepper (Solanaceae), Tahiti lime and key lime (Rutaceae) hosts evidenced high genetic differentiation between populations associated with different hosts and an absence of gene flow between these groups, suggesting the corresponding formation of cryptic species.

scholarly journals Disproportionate extinction of South American mammals drove the asymmetry of the Great American Biotic Interchange

2020 ◽  
Vol 117 (42) ◽  
pp. 26281-26287 ◽  
Author(s):  
Juan D. Carrillo ◽  
Søren Faurby ◽  
Daniele Silvestro ◽  
Alexander Zizka ◽  
Carlos Jaramillo ◽  
...  
Keyword(s):  
South America ◽  
North American ◽  
Biotic Interactions ◽  
South American ◽  
Dispersal Rate ◽  
Great American Biotic Interchange ◽  
Drastic Increase ◽  
The Asymmetry ◽  
North And South America ◽  
North And South

The interchange between the previously disconnected faunas of North and South America was a massive experiment in biological invasion. A major gap in our understanding of this invasion is why there was a drastic increase in the proportion of mammals of North American origin found in South America. Four nonmutually exclusive mechanisms may explain this asymmetry: 1) Higher dispersal rate of North American mammals toward the south, 2) higher origination of North American immigrants in South America, 3) higher extinction of mammals with South American origin, and 4) similar dispersal rate but a larger pool of native taxa in North versus South America. We test among these mechanisms by analyzing ∼20,000 fossil occurrences with Bayesian methods to infer dispersal and diversification rates and taxonomic selectivity of immigrants. We find no differences in the dispersal and origination rates of immigrants. In contrast, native South American mammals show higher extinction. We also find that two clades with North American origin (Carnivora and Artiodactyla) had significantly more immigrants in South America than other clades. Altogether, the asymmetry of the interchange was not due to higher origination of immigrants in South America as previously suggested, but resulted from higher extinction of native taxa in southern South America. These results from one of the greatest biological invasions highlight how biogeographic processes and biotic interactions can shape continental diversity.

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