Trophic diversity in past and present guilds of large predatory mammals

Paleobiology ◽  
1988 ◽  
Vol 14 (2) ◽  
pp. 155-173 ◽  
Author(s):  
Blaire Van Valkenburgh
Keyword(s):  
Sympatric Species ◽  
Taxonomic Composition ◽  
Adaptive Divergence ◽  
Dental Morphology ◽  
Morphological Divergence ◽  
Trophic Diversity ◽  
Time Space ◽  
Feeding Type ◽  
Adaptive Diversity ◽  
Dental Measurements

Trophic diversity within guilds of terrestrial predators is explored in three modern and two ancient communities. The modern communities span a range of environments including savannah, rainforest, and temperate forest. The paleocommunities are North American, Orellan (31–29 Ma), and late Hemphillian (7–6 Ma), respectively. The predator guilds are compared in terms of: 1) species richness; 2) the array of feeding types; and 3) the extent of morphological divergence among sympatric species. Feeding type is determined from dental measurements that reflect the proportion of meat, bone, and non-vertebrate foods in the diet. Measurements include estimates of canine shape, tooth size, cutting blade length, and grinding molar area. Morphological divergence among sympatric predators is measured by calculating Euclidean distances among species in a six-dimensional morphospace. Results indicate that the number of predator and prey species are roughly correlated in both ancient and modern communities. Two of the predator guilds, the late Hemphillian and modern Yellowstone, contain relatively few species and appear to be the result of extinction without replacement. Despite differences in history, age, and environment, the extent of morphological divergence within guilds does not differ significantly for the sampled communities. It is clear that the basic pattern of adaptive diversity in dental morphology among coexisting carnivores was established at least 32 million years ago. It appears that interspecific competition for food has acted similarly to produce adaptive divergence among sympatric predators in communities that differ widely in time, space, and taxonomic composition.

scholarly journals Trophic specialization and morphological divergence between two sympatric species in Lake Catemaco, Mexico

2018 ◽  
Vol 8 (10) ◽  
pp. 4867-4875 ◽  
Author(s):  
Claudia Patricia Ornelas-García ◽  
Fernando Córdova-Tapia ◽  
Luis Zambrano ◽  
María Pamela Bermúdez-González ◽  
Norman Mercado-Silva ◽  
...  
Keyword(s):  
Sympatric Species ◽  
Morphological Divergence ◽  
Trophic Specialization

scholarly journals Paleogene community change among terrestrial vertebrates of the Western Hemisphere

1992 ◽  
Vol 6 ◽  
pp. 282-282
Author(s):  
Richard K. Stucky
Keyword(s):  
North America ◽  
South America ◽  
Community Change ◽  
Taxonomic Composition ◽  
Western Hemisphere ◽  
Dental Morphology ◽  
Predator Prey ◽  
Terrestrial Vertebrates ◽  
Morphological Adaptations ◽  
Dinosaur Extinction

Paleogene vertebrate communities in North and South America show dramatic changes in taxonomic composition and ecological organization. Worldwide, mammals diversified substantially following dinosaur extinction (Fig. 1). Most families of living vertebrates appear by the end of the Paleogene. In North America, placental omnivores, herbivores and carnivores dominate mammalian communities, but in South America marsupial carnivores and omnivores and placental herbivores dominate them. Immigration from Asia and Europe to North America of taxa from several placental orders (Perissodactyla, Primates, Artiodactyla, Rodentia, Carnivora, Mesonychia, Creodonta) occurred periodically during the Paleogene. South America, however, was completely isolated from the Paleocene to the Oligocene when Rodentia and perhaps Primates first appear. Despite the independent evolutionary histories of these continents, their constituent species show remarkable convergences in morphological adaptations including body size distributions, dental morphology, and other features. Low resolution chronostratigraphic data for the Paleogene of South America precludes correlation with North American faunas. In North America, patterns of diversification and extinction appear to be related to climatic events. Morphological convergences appear to be related to climate and concomitant habitat change, but may also be a function of coevolution via predator-prey interactions and diffuse competition among guild members.

scholarly journals Intestinal microbiota of whitefish (Coregonus sp.) species pairs and their hybrids in natural and controlled environment

2018 ◽  
Author(s):  
Maelle Sevellec ◽  
Martin Laporte ◽  
Alex Bernatchez ◽  
Nicolas Derome ◽  
Louis Bernatchez
Keyword(s):  
Intestinal Microbiota ◽  
Sympatric Species ◽  
Taxonomic Composition ◽  
Rrna Gene ◽  
Coregonus Clupeaformis ◽  
Symbiotic Interactions ◽  
Species Pairs ◽  
In The Wild ◽  
Species Effect ◽  
Evolutionary Paths

AbstractIt is becoming increasingly clear that wild animals have never existed without symbiotic interactions with microbiota. Therefore, investigating relationships between microbiota and their host is essential towards a full understanding of how animal evolve and adapt to their environment. The Lake Whitefish (Coregonus clupeaformis) is a well-documented model for the study of ecological speciation, where the dwarf species (limnetic niche specialist) evolved independently and repeatedly from the normal species (benthic niche specialist). In this study, we compared the transient intestinal microbiota among five wild sympatric species pairs of whitefish as well as captive representatives of dwarf and normal species and their reciprocal hybrids reared in identical controlled conditions. We sequenced the 16s rRNA gene V3-V4 regions of the transient intestinal microbiota present in a total of 185 whitefish to (i) test for parallelism in the transient intestinal microbiota among sympatric pairs of whitefish, (ii) test for transient intestinal microbiota differences among dwarf, normal and both hybrids reared under identical conditions and (iii) compare intestinal microbiota between wild and captive whitefish. A significant effect of host species on microbiota taxonomic composition was observed in the wild when all lakes where analyzed together, and species effect was observed in three of the five species pairs. In captive whitefish, an influence of host (normal, dwarf and hybrids) was also detected on microbiota taxonomic composition and tens of genera specific to dwarf, normal or hybrids were highlighted. Hybrid microbiota was not intermediate; instead its composition fell outside of that observed in the parental forms and this was observed in both reciprocal hybrid crosses. Interestingly, six genera formed a bacterial core which was present in captive and wild whitefish, suggesting a horizontal microbiota transmission. Although diet appeared to be a major driving force for microbiota evolution, our results suggested a more complex interaction among the host, the microbiota and the environment leading to three distinct evolutionary paths of the intestinal microbiota.

scholarly journals ORIENTATION VS. ORIENTATION: IMAGE PROCESSING FOR STUDIES OF DENTAL MORPHOLOGY

2021 ◽  
Vol XLIII-B2-2021 ◽  
pp. 723-728
Author(s):  
A. V. Gaboutchian ◽  
V. A. Knyaz ◽  
S. V. Vasilyev ◽  
D. V. Korost ◽  
A. A. Kudaev
Keyword(s):  
Image Processing ◽  
3D Reconstruction ◽  
Archaeological Site ◽  
Current Paper ◽  
Dental Morphology ◽  
Micro Computed Tomography ◽  
Computed Tomographic ◽  
Central Russia ◽  
Wide Range ◽  
Dental Measurements

Abstract. Many odontological studies held through application of traditional and modern techniques, especially when related to measurements and morphology, very much depend on methodological aspects referred to orientation of teeth. And this is particularly relevant to new imaging and 3d reconstruction implemented in dental research and practice in a wide range of disciplines from anthropology to dentistry. The current paper deals with studies of palaeoanthropological findings dating back to the Upper Palaeolithic period in Central Russia – well-known archaeological site of Sunghir. Micro-computed tomography has been used for digital reconstructions of teeth – molars and premolars representing well-preserved dental morphology of an adolescent individual. This is due to new opportunities introduced by 3d reconstruction techniques in general and high-resolution x-ray imaging in particular that this study has become relevant. Thus digital techniques do not only provide for operating convenience but, which is even more important, allow application of image processing algorithms. In the suggested methodology these are automated, based on morphological interpretations and serve for orientation of studied teeth for further measurements. At the same time micro-computed tomographic imaging allows accurate reconstruction of other morphologically important structures which are used for an alternative orientation algorithm. Comparisons of dental measurements’ results obtained through automated digital odontometry (aDo) after both orientations applied are presented in the current paper.

scholarly journals Morfología funcional del fitoplancton en un lago de alta montaña tropical: Lago de Tota (Boyacá-Colombia)

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Claudia Liliana Muñoz López ◽  
Nelson Javier Aranguren Riaño ◽  
Santiago Roberto Duque Escobar
Keyword(s):  
Oxygen Saturation ◽  
Seasonal Changes ◽  
Volume Ratio ◽  
Taxonomic Composition ◽  
Total Hardness ◽  
Adaptive Responses ◽  
Monthly Basis ◽  
Algae Biomass ◽  
Time Space ◽  
The Relationship

Functional morphology corresponds to adaptive responses to changes in the environment. In phytoplankton, traits such as the development of mucilage, oil vesicles, filaments and variation in the surface/volume ratio, allow algae to deal with sedimentation, optimizing light and nutrient uptake. The aim of this research was to evaluate the relationship between traits and variation in physical and chemical conditions in Tota Lake (Boyacá, Colombia). For this, ten samplings were undertaken in a monthly basis between October 2013 and July 2014. We measured water pH, conductivity, temperature, dissolved oxygen, oxygen saturation, alkalinity and total hardness; we also quantified Total Kjeldahl nitrogen and Total phosphorus. Algae were collected at different depths according to Secchi transparency. Taxonomic composition and abundance were estimated by the chamber sedimentation method. Morphological traits were measured for each taxa according to geometric models, allowing traits classification into morphologically based functional groups (MBFG) and having algae biomass expressed as biovolume. The variables were evaluated through Principal Components Analysis, which included time-space effect and it was interpreted according to variation in water level. Through Canonical Correspondence Analysis we established the relationship between phytoplankton biovolume accumulated in form categories and environmental variables. The ordination showed that limnological conditions are influenced by seasonal changes, which are mainly represented by oxygen saturation percentage, Secchi transparency, TKN, hardness and alkalinity. Four MBFG were found: IV, V, VI and VII, being MBFG IV and VII the most representatives. ACC was significant (Monte-Carlo Test, p<0.05). In conclusion, the morphological and functional response of phytoplankton in Tota Lake is driven by short-term variability in transparency, phosphorus, nitrogen, hardness, and electrical conductivity, which are all affected by seasonal changes in the lake level.

scholarly journals Structural-functional organization of littoral zooplankton community of the upper Kremenchug reservoir in the territory of Kaniv nature reserve

2018 ◽  
Vol 75 (1) ◽  
pp. 45-49
Author(s):  
Z. Burian ◽  
V. Gandziura ◽  
V. Trokhymets
Keyword(s):  
Nature Reserve ◽  
Functional Organization ◽  
Zooplankton Community ◽  
Taxonomic Composition ◽  
Larval Stages ◽  
Species Complexes ◽  
Feeding Type ◽  
Cladoceran Zooplankton ◽  
Quantitative Indicators ◽  
Kremenchug Reservoir

The analysis results of the structural-functional organization of littoral zooplankton community of the upper Kremenchug Reservoir in the territory of Kaniv Nature Reserve during the summer of 2015 are presented. Diversity of zooplankton was presented with 34 species: Monogononta rotifers, cladocerans, copepods. The rotatoria-cladoceran zooplankton complex dominated in the taxonomic composition. Zhakkara dominant index for the comparison of the dominant species complexes was used, and it was the low number of similarities within the various biotopes of the six research stations (J = 7,1-28,6). This can be explained by the formation of higher aquatic plants.This led to the formation of specific zooplankton groups in overgrown biotopes.The ecological spectrum of the different groups of the upper Kremenchug Reservoir littoral zooplankton in the summer was characterized by the predominance of the phytophilic groups: phytophilic – 18 species (53 % of all zooplankton species). Depending on the feeding type the largest part was made by the peaceful group – 73,3 % (25 species). Summer littoral zooplankton in quantitative terms was characterized by very low development in both biotopes. Its density varied within 4077± 2098 ind./m³ and biomass 0,07 ± 0,04 g/m for overgrown biotopes, and 4123 ± 3929 ind./m³ and 0,054 ± 0,038 g/m³ for freshwater ones. Among the quantitative indicators, the species of Copepoda dominated, what was associated with the development of their larval stages (Nauplia, Сalanoida juv., Cyclopoida juv.) in the summer period.

Biology, Management, and Conservation of Lampreys in North America

2009 ◽  
Keyword(s):  
Life History ◽  
Sexual Maturation ◽  
Distinct Species ◽  
Sympatric Species ◽  
Reciprocal Monophyly ◽  
Species Pairs ◽  
Feeding Type ◽  
Species Specific ◽  
Lamprey Species ◽  
Paired Species

<em>Abstract</em>.—In most lamprey genera, “paired” species exist in which the larvae (which are microphagous filter feeders) are morphologically similar but the adults differ dramatically, becoming parasitic on teleost fishes or nonparasitic (i.e., do not feed at all) following metamorphosis. Parasitic lampreys feed for several months to several years (either in their natal stream or after migrating to larger fresh or marine water bodies) before embarking on a nontrophic upstream migration, sexual maturation, and spawning (followed by death); nonparasitic lampreys eliminate the parasitic phase, begin sexual maturation toward the end of metamorphosis, and spawn and die within 6–10 months of metamorphosis. In each species pair, the reduction in the length of postlarval life in nonparasitic lampreys is generally accompanied by an increase in the length of the larval period (and size at metamorphosis) so that the evolution of nonparasitism appears to have occurred without a change in the overall life span. Rather, nonparasitism appears to have evolved as a result of a change in the timing of metamorphosis relative to the timing of sexual maturation. Conspicuous morphological (e.g., adult body size, relative eye and oral disk size) and histological (e.g., lack of a functional digestive tract) differences distinguish nonparasitic adults from parasitic forms, and most lamprey taxonomists recognize life history type as a species-specific characteristic. However, plasticity of feeding type (e.g., facultative parasitism) has been observed in some lamprey populations, and molecular data on a number of paired species show no genetic differentiation between sympatric species pairs and suggest a polyphyletic origin for several nonparasitic species. This paper reviews the paired species concept, the repeated and independent evolution of nonparasitism in different genera and even within species, the evidence for facultative parasitism or facultative nonparasitism in some lamprey species, and the potential for hybridization between paired species and attempts to answer the question, are brook lampreys “real” species? The tentative answer is that there likely is not a single answer for all lamprey species pairs; different species pairs represent speciation at different stages. Some pairs appear to be distinct species according to both the biological and phylogenetic species concepts (i.e., they are reproductively isolated and show reciprocal monophyly), although each is not necessarily fixed for feeding type. In contrast, other pairs may represent incipient speciation and others yet may be experiencing ongoing gene flow. Parallels are therefore drawn between different lamprey species pairs and the divergent life history types found in other animal taxa (e.g., echinoderms and amphibians) and other temperate fish species (e.g., anadromous and freshwater-resident salmonids).

scholarly journals Symbiotic cyanobacteria communities in hornworts across time, space, and host species

2020 ◽  
Author(s):  
Jessica M. Nelson ◽  
Duncan A. Hauser ◽  
Fay-Wei Li
Keyword(s):  
New York ◽  
Phylogenetic Diversity ◽  
Growing Season ◽  
Sympatric Species ◽  
Soil Samples ◽  
Host Factors ◽  
Upstate New York ◽  
Time Space ◽  
Long Reads ◽  
Microbe Interactions

SummaryRationaleWhile plant-microbe interactions have been intensively studied in mycorrhizal and rhizobial symbioses, much less is known about plant symbioses with nitrogen-fixing cyanobacteria. Here we focused on hornworts (a bryophyte lineage), and investigated the diversity of their cyanobionts and how these communities are shaped by spatial, temporal, and host factors.MethodWe carried out repeated samplings of hornwort and soil samples in upstate New York throughout the growing season. Three sympatric hornwort species were included, allowing us to directly compare partner specificity and selectivity. To profile cyanobacteria communities, we established a new metabarcoding protocol targeting rbcL-X with PacBio long reads.ResultsHornwort cyanobionts have a high phylogenetic diversity, including clades that do not contain other known plant or lichen symbionts. While the sympatric hornwort species have similarly low specificity, they exhibit different preferences toward cyanobionts, although this depended on what cyanobacteria were present in the soil. Cyanobacterial communities varied spatially, even at small scales, but time did not play a major organizing role.Conclusion.This study highlights the importance of sampling soil and sympatric species to infer partner compatibility and preference, and marks a critical step toward better understanding the ecology and evolution of plant-cyanobacteria symbiosis.

New characters for species discrimination within the genus Prolagus (Ochotonidae, Lagomorpha, Mammalia)

2009 ◽  
Vol 83 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Chiara Angelone ◽  
Carmen Sesé
Keyword(s):  
Relative Length ◽  
Intraspecific Variability ◽  
Morphological Characters ◽  
Sympatric Species ◽  
Species Discrimination ◽  
Northern Spain ◽  
Taxonomic Assignment ◽  
Late Middle Miocene ◽  
Western Asia ◽  
Dental Measurements

The genus Prolagus is very common in the Neogene and Quaternary of Europe, western Asia and northern Africa. However, the complexity of its systematics, mainly based on p3 characters that show great inter- and intraspecific variability, led to an under-utilization of Prolagus in biochronology and palaeogeography studies. A re-analysis of the species of Prolagus recorded in the Escobosa de Calatañazor karst fissure fillings (Duero Basin, northern Spain, MN7/8, late Middle Miocene) includes the introduction of new maxillary and mandibular morphological characters (position, shape and size of premolar and mandibular foramina) and new dental measurements (hypoflexus depth, distal hypercone length, and partial width of upper premolars; relative length of trigonid of lower molariform teeth) to be used for species discrimination within the genus Prolagus. The new morphological characters and measurements introduced in this paper allow for a more accurate taxonomic assignment of Prolagus species, thus improving the estimation of faunal palaeodiversity, detection of sympatric species and taphonomic mixing, and contributing to more reliable biochronological, palaeogeographical, and phylogenetic inferences based on Prolagus.

Relationships among morphology, geography, and interfertility in Medicago

1986 ◽  
Vol 64 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Ernest Small ◽  
L. P. Lefkovitch
Keyword(s):  
Geographical Distribution ◽  
Related Species ◽  
Positive Relationship ◽  
Morphological Characters ◽  
Sympatric Species ◽  
Morphological Divergence ◽  
Closely Related Species ◽  
Geographical Separation ◽  
The Relationship ◽  
Numerical Examination

A numerical examination was conducted of the relationships among 99 morphological characters, geographical distribution, and ability to hybridize among the 55 species of the Old World genus Medicago (Leguminosae) currently recognized. Nearest morphological neighbours were found to be much more likely to be crossable than other species combinations. More than half of the species combinations proved to have sympatric geographical ranges. Sympatric species were not found to be significantly more crossable than nonsympatric species. Sympatry was not found to be significantly different in frequency among closely related species than among less closely related species. Using Lefkovitch's measure of biogeographical distance, a positive relationship between morphological divergence and geographical separation was demonstrated. However, the relationship was not strong. This may be due to the very large mean intercentroid distance found between the 54 pairs of nearest morphological neighbours, about 2800 km. This suggests that geographical divergence has developed so extensively between even the most closely related species of Medicago that random species migrations have substantially obscured relationships.

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