Classical Morphometrics Research Articles

Geometric morphometrics clarifies the taxonomic status of semifossorial shrews (Eulipotyphla, Soricidae, Cryptotis) from Mexican cloud forests

Abstract The small-eared shrews Cryptotis mexicanus and Cryptotis obscurus (Eulipotyphla, Soricidae) are two closely related taxa from the northern Neotropics whose taxonomy is still unresolved. Here, we tested the hypothesis of three lineages (Northern, Central, and Southern) within this pair of semifossorial shrews. We photographed skulls, dentaries, and humeri from 226 museum specimens and used geometric morphometrics to evaluate sexual dimorphism, differences between lineages, and the effect of the environment on the shape of the structures. We found negligible differences between males and females, supporting previous studies of classical morphometrics in this genus. Our results also support the differentiation of semifossorial shrews into the three geographically isolated groups, where the size of the dentary and the shape of the three examined structures contribute to discrimination. We found a significant sign of the influence of the environment on the shape of the dentary but not on the skull or the humerus. We suggest that geographic isolation across climatically similar regions has contributed to the differentiation between lineages. We propose recognizing all three lineages as valid species that must be adequately described.

Three-dimensional analysis of modeled facial aging and sexual dimorphism from juvenile to elderly age

A detailed understanding of craniofacial ontogenetic development is important in a variety of scientific disciplines dealing with facial reconstruction, forensic identification, ageing prediction, and monitoring of pathological growth, including the effect of therapy. The main goals of this study were (1) the construction of the facial aging model using local polynomial regression fitting separately for both sexes, (2) evaluation of the aging effect not only on facial form as a whole but also on dimensions important for clinical practice, and (3) monitoring of the development of shape facial sexual dimorphism. Our study was based on the form and shape analysis of three-dimensional facial surface models of 456 individuals aged 14–83 years. The facial models were obtained using a structured light-based optical scanner and divided (for some analyses) into four age categories (juveniles, young adults, middle adults, and elderly adults). The methodology was based on geometric and classic morphometrics including multivariate statistics. Aging in both sexes shared common traits such as more pronounced facial roundness reducing facial convexity, sagging soft tissue, smaller visible areas of the eyes, greater nose, and thinner lips. In contrast to female faces, male faces increase in size until almost 30 years of age. After the age of 70, male facial size not only stagnates, like in females, but actually decreases slightly. Sexual dimorphic traits tended to diminish in the frontal and orbitonasal areas and increase in the gonial area.

Classical Morphometrics in V. arvensis and V. kitaibeliana (Viola sect. Melanium) Reveals Intraspecific Variation with Implications for Species Delimitation: Inferences from a Case Study in Central Italy.

The high morphological variability of Viola arvensis may hinder the proper identification of the closely related species with an implication for biodiversity surveys. Variation in floral and vegetative morphology was explored in V. arvensis, compared to V. kitaibeliana, based upon 14 wild Italian populations, to provide new insights into their diagnostic features. Species were characterized using 32 morphological descriptors assessed on 272 flowers and as many leaves and scored as quantitative and categorical variables. Statistical methods, including Linear Discriminant Analysis (LDA), were applied to test species delimitation. Data highlighted variations in sepal size, petal size, leaves shape, stylar dark spot, and pollen magazine higher within V. arvensis than between V. arvensis and V. kitaibeliana. LDA partitioned the V. arvensis samples into two distinct clusters; no clear distinction was found between the cluster combining individuals from grasslands and V. kitaibeliana. The separation of V. arvensis and V. kitaibeliana from V. tricolor, included as a reference, was noticeable. Correlations were found in all species between the flower/leaf position on the stem and some floral and vegetative features. The shape and margin of the lower sepal, the stylar flap, and the lamina margin and apex were diagnostic in field identification. The results support the recognition of an undescribed V. arvensis eco-phenotype linked to seminatural dry grasslands, easily distinguishable from the field-grown type of V. arvensis but hardly distinguishable from the dwarf pansy. Data further corroborate the assumption of general deep-rooted confusion in ascribing poorly developed individuals of V. arvensis to the rare and locally threatened V. kitaibeliana, leading to potential implications for its conservation.

Shrews (Mammalia, Eulipotyphla) from a biodiversity hotspot, Mount Nimba (West Africa), with a field identification key to species

In this study, we collected 226 shrew specimens originating from 16 localities on the Guinean and Liberian sides of Mount Nimba. We surveyed all major vegetation zones from 400 to 1600 m above sea level (asl), including forest and savannah habitats. We recorded 11 species, whose identifications were confirmed by genetic analyses and classical morphometrics. Furthermore, we provide cytogenetic data for five of these species. The shrew community at Mount Nimba is composed of a mix of both savannah- and forest-dependent species, which is related to the peculiar position of Mount Nimba situated at the transition between lowland rainforest to the south and Guinean woodlands to the north. We recorded 11 species of shrews in syntopy in lowland rainforest, seven in edaphic savannah and mountain forest, and five in high-altitude savannah at 1600 m asl. Based on morphometric analyses, we show that these syntopic species separate along a size axis, allowing species to occupy different ecological niches, which we speculate allows them to access different food resources. We also highlight that Crocidura theresae Heim de Balsac, 1968 from Mount Nimba has a different karyotype from that described in Côte d'Ivoire. Finally, we develop a novel identification key for shrews from Mount Nimba using external characters and standard body measurements, allowing it to be used in the field on live specimens. In total 12 shrew species are now known from Mount Nimba, which highlights its exceptional position as a tropical African biodiversity hotspot.

Quantifying bite force in coexisting tayassuids and feral suids: a comparison between morphometric functional proxies and in vivo measurements.

BackgroundMeasuring mammals’ bite force in laboratory conditions is not a simple task, let alone on wild medium-sized mammals in the field. Thus, morphometric-proxies are usually used to infer morphofunctional properties of musculoskeletal features. For instance, the study of bite force-indexes suggests that different capacities to crack food items reduce the competition between coexistent collared and white-lipped peccaries (Pecari tajacu and Tayassu pecari). The presence of exotic feral hogs (Sus scrofa) in peccaries’ endemic areas gives rise to new ecological interactions between them. An example is the Brazilian Pantanal wetland, where ecomorphological mechanisms may play a role in their ecological relations. Taking this scenario as a case of study, we aimed to verify if the morphometric-proxies are de facto reliable tools, by comparing bite forces-indexes with the in vivo bite forces of these species.MethodsWe captured 21 collared and white-lipped peccaries and feral hogs in the Brazilian Pantanal to assess their bite force at first molar. The Bite Force Measuring Tube (BiTu) is a robust and simple mechanical device designed to be used in field conditions. Only 11 individuals successfully bit the BiTu before being released. Their body measurements were compared and correlated with their bite force. The in vivo bite forces were compared with bite force-indexes of two papers based on independent morphometric methods and datasets: Sicuro & Oliveira (2002) used classic morphometrics to infer the bite forces of these three species in the Brazilian Pantanal, and Hendges et al. (2019) used geometric morphometrics to compare bite forces-indexes and feeding habits of the extant peccary species. The results of all species were standardized (Z-curves) according to each method. Doing so, we obtained comparable dimensionless comparable values but maintaining the differences between them.ResultsThe morphometric-proxies-based studies presented similar results: collared peccaries present weaker bites than white-lipped peccaries and feral hogs, while these two species presented no significant differences in their bite force-indexes. The in vivo bite force results suggest the same relations predicted by the morphometric models, including the high variation among the feral hogs. We found a significant correlation between the individuals’ weight (kg) and their actual bite force (N) but no significant correlations with the head length.ConclusionsThe BiTu proved to be a functional and low-cost tool to measure bite force in field conditions. The in vivo results presented a good correspondence with the predictions based on morphometric-proxies by Sicuro & Oliveira (2002) and Hendges et al. (2019). The results denote that these studies succeed in capturing the biomechanical signal of the three species’ skull-jaw systems. This empirical validation confirms that these morphometric-proxies analyses are reliable methods to ecomorphological and evolutionary inferences.

Identifying geographically differentiated features of Ethopian Nile tilapia (Oreochromis niloticus) morphology with machine learning.

Visual characteristics are among the most important features for characterizing the phenotype of biological organisms. Color and geometric properties define population phenotype and allow assessing diversity and adaptation to environmental conditions. To analyze geometric properties classical morphometrics relies on biologically relevant landmarks which are manually assigned to digital images. Assigning landmarks is tedious and error prone. Predefined landmarks may in addition miss out on information which is not obvious to the human eye. The machine learning (ML) community has recently proposed new data analysis methods which by uncovering subtle features in images obtain excellent predictive accuracy. Scientific credibility demands however that results are interpretable and hence to mitigate the black-box nature of ML methods. To overcome the black-box nature of ML we apply complementary methods and investigate internal representations with saliency maps to reliably identify location specific characteristics in images of Nile tilapia populations. Analyzing fish images which were sampled from six Ethiopian lakes reveals that deep learning improves on a conventional morphometric analysis in predictive performance. A critical assessment of established saliency maps with a novel significance test reveals however that the improvement is aided by artifacts which have no biological interpretation. More interpretable results are obtained by a Bayesian approach which allows us to identify genuine Nile tilapia body features which differ in dependence of the animals habitat. We find that automatically inferred Nile tilapia body features corroborate and expand the results of a landmark based analysis that the anterior dorsum, the fish belly, the posterior dorsal region and the caudal fin show signs of adaptation to the fish habitat. We may thus conclude that Nile tilapia show habitat specific morphotypes and that a ML analysis allows inferring novel biological knowledge in a reproducible manner.

Disentangling Ethiopian Honey Bee (Apis mellifera) Populations Based on Standard Morphometric and Genetic Analyses.

Simple SummaryWe conducted this population study of Ethiopian honey bees, using morphometric and genetic methods, to decipher their controversial classification. These honey bees are highly diverse and showed differentiation based on size and genetic information according to prevailing agro-ecological conditions, demonstrating morphological and molecular signatures of local adaptation. The results of both morphometric and genetic analyses suggest that Ethiopian honey bees differ from populations in the neighboring geographic regions and are characterized by extensive gene flow within the country, enhanced by honey bee colony trade. Consequently, future research that includes studying traits of vitality, behavior and colony performance of honey bees in remaining pocket areas of highland agro-ecological zones could contribute to the development of appropriate conservation management.The diversity and local differentiation of honey bees are subjects of broad general interest. In particular, the classification of Ethiopian honey bees has been a subject of debate for decades. Here, we conducted an integrated analysis based on classical morphometrics and a putative nuclear marker (denoted r7-frag) for elevational adaptation to classify and characterize these honey bees. Therefore, 660 worker bees were collected out of 66 colonies from highland, midland and lowland agro-ecological zones (AEZs) and were analyzed in reference to populations from neighboring countries. Multivariate morphometric analyses show that our Ethiopian samples are separate from Apis mellifera scutellata, A. m. jemenitica, A. m. litorea and A. m. monticola, but are closely related to A. m. simensis reference. Linear discriminant analysis showed differentiation according to AEZs in the form of highland, midland and lowland ecotypes. Moreover, size was positively correlated with elevation. Similarly, our Ethiopian samples were differentiated from A. m. monticola and A. m. scutellata based on r7-frag. There was a low tendency towards genetic differentiation between the Ethiopian samples, likely impacted by increased gene flow. However, the differentiation slightly increased with increasing elevational differences, demonstrated by the highland bees that showed higher differentiation from the lowland bees (FST = 0.024) compared to the midland bees (FST = 0.015). An allelic length polymorphism was detected (denoted as d) within r7-frag, showing a patterned distribution strongly associated with AEZ (X2 = 11.84, p < 0.01) and found predominantly in highland and midland bees of some pocket areas. In conclusion, the Ethiopian honey bees represented in this study are characterized by high gene flow that suppresses differentiation.

Genetic Evidence of Introduced Redeye Bass and Alabama Bass and Hybridization with Native Micropterus spp. in Town Creek, Alabama, USA

AbstractThe black basses Micropterus spp. are among the most important game fishes in the United States. Translocation by both anglers and state agencies for increased angling opportunity has led to widespread hybridization between native and nonnative species. The use of species‐diagnostic single‐nucleotide polymorphism (SNP) markers for black basses has allowed for rapid assessment of species identification and hybridization in rivers and streams. Here, we report genetic evidence for the presence of Redeye Bass M. coosae and Alabama Bass M. henshalli outside of their native range and their hybridization with native species of black bass in Town Creek, a tributary of the Tennessee River. To determine which black bass species were present in the creek, four sites were sampled using both angling and backpack electrofishing. Sampled DNA from fin clips was analyzed using a diagnostic SNP panel. Genetic results confirmed that Redeye Bass and Alabama Bass were present as nonnative congeners in the creek. Interestingly, no pure individual Smallmouth Bass M. dolomieu or Spotted Bass M. punctulatus were found, although both species are native to the stream. Phenotypic identification followed by genotypic classification revealed that 62% of the fish collected for this study were misidentified in the field, with 100% of those being hybrids, indicating the importance of genetic assessment in conjunction with classic morphometrics for the management of black basses. Further studies are needed to determine whether seasonality plays a role in species presence and abundance and whether population profiles identified here are observed more broadly within the Tennessee River system.

Isolated teeth from La Ferrassie: Reassessment of the old collections, new remains, and their implications.

We provide the description and comparative analysis of six new teeth from the site of La Ferrassie. Our goal is to discuss their taxonomic attribution, and to provide an updated inventory of Neandertal and modern human remains from La Ferrassie in their associated archeological context. We use external and internal anatomy, classic morphometrics, and geometric morphometrics. The teeth from La Ferrassie are compared to several samples of contemporary Neandertals and upper Paleolithic modern humans and to recent modern humans. Three specimens are classified as Neandertals, two as modern humans, and one remains unclassified. Based on the previously known fossil samples and the new teeth reported here, there are currently a minimum of four adult and five immature Neandertal individuals coming from the "Grand Abri" and a minimum of two modern human adult individuals: one from "Grand Abri" and one from "Grotte." It is noteworthy that the spatial distribution of the recovered Neandertal remains is not restricted to the area where the LF1-LF 8 were found but now covers the full extension of the excavated area. Moreover, while both Neandertal and modern human occupations have yielded isolated human remains, the partial-to-complete skeletons only belong to Neandertals. These considerations open new perspectives for the understanding of the occupation and use of the La Ferrassie site.

Classical and geometric morphometric methods reveal differences between specimens of Varroa destructor (Mesostigmata: Varroidae) from seven provinces of Iran

Varroa destructor Anderson & Truman is the most serious pest of honey bee colonies all over the world. Its specimens were assessed by morphometric and geometric morphometric methods using six morphometric traits including body length and width, length and width of the right metapodal shield, length of epigynal and the anal shield for classical morphometrics and six landmarks in ventral surface of mite's body, in seven provinces including Ardabil, Markazi, Qom, Qazvin, Alborz, North Khorasan, and Semnan. Twenty and ten individuals were used for morphometric and geometric morphometric studies, respectively. The ventral surface of each mite slide was prepared and used Digimizer and Tps package software for morphometric and geometric morphometric measurements, respectively. Data were analyzed with Past software. Furthermore, principal component analysis (PCA) was used for both two methods. In addition, Cluster analysis was used to categorize specimens of provinces. The results demonstrated significantly morphometric and geometric morphometric (or shape and size) differences among the specimens of provinces. Qazvin and Ardabil were located in one group with the PCA and Cluster analysis in the classical morphometric method and Alborz mite's dimensions showed a significant difference in morphometric measurements with other provinces. However, in the geometric morphometric method, Ardabil, Markazi, North Khorasan, and Semnan specimens were located in another group. The difference in distribution can be related to geographical factors and methods of measurement.

Squamation and ecology of thelodonts.

Thelodonts are an enigmatic group of Paleozoic jawless vertebrates that have been well studied from taxonomical, biostratigraphic and paleogeographic points of view, although our knowledge of their ecology and mode of life is still scant. Their bodies were covered by micrometric scales whose morphology, histology and the developmental process are extremely similar to those of extant sharks. Based on these similarities and on the well-recognized relationship between squamation and ecology in sharks, here we explore the ecological diversity and lifestyles of thelodonts. For this we use classic morphometrics and discriminant analysis to characterize the squamation patterns of a significant number of extant shark species whose ecology is well known. Multivariate analyses have defined a characteristic squamation pattern for each ecological group, thus establishing a comparative framework for inferring lifestyles in thelodonts. We then use this information to study the squamation of the currently described 147 species of thelodonts, known from both articulated and disarticulated remains. Discriminant analysis has allowed recognizing squamation patterns comparable to those of sharks and links them to specific ecological groups. Our results suggest a remarkable ecological diversity in thelodonts. A large number of them were probably demersal species inhabiting hard substrates, within caves and crevices in rocky environments or reefs, taking advantage of the flexibility provided by their micromeric squamations. Contrary to classical interpretations, only few thelodonts were placed among demersal species inhabiting sandy and muddy substrates. Schooling species with defensive scales against ectoparasites could be also abundant suggesting that social interactions and pressure of ectoparasites were present in vertebrates as early the Silurian. The presence of species showing scales suggestive of low to moderate speed and a lifestyle presumably associated with open water environments indicates adaptation of thelodonts to deep water habitats. Scale morphology suggests that some other thelodonts were strong-swimming pelagic species, most of them radiating during the Early Devonian in association with the Nekton Revolution.

The heritability of chimpanzee and human brain asymmetry.

Human brains are markedly asymmetric in structure and lateralized in function, which suggests a relationship between these two properties. The brains of other closely related primates, such as chimpanzees, show similar patterns of asymmetry, but to a lesser degree, indicating an increase in anatomical and functional asymmetry during hominin evolution. We analysed the heritability of cerebral asymmetry in chimpanzees and humans using classic morphometrics, geometric morphometrics, and quantitative genetic techniques. In our analyses, we separated directional asymmetry and fluctuating asymmetry (FA), which is indicative of environmental influences during development. We show that directional patterns of asymmetry, those that are consistently present in most individuals in a population, do not have significant heritability when measured through simple linear metrics, but they have marginally significant heritability in humans when assessed through three-dimensional configurations of landmarks that reflect variation in the size, position, and orientation of different cortical regions with respect to each other. Furthermore, genetic correlations between left and right hemispheres are substantially lower in humans than in chimpanzees, which points to a relatively stronger environmental influence on left-right differences in humans. We also show that the level of FA has significant heritability in both species in some regions of the cerebral cortex. This suggests that brain responsiveness to environmental influences, which may reflect neural plasticity, has genetic bases in both species. These results have implications for the evolvability of brain asymmetry and plasticity among humans and our close relatives.

Species delimitation using morphology, morphometrics, and molecules: definition of the Ophionscutellaris Thomson species group, with descriptions of six new species (Hymenoptera, Ichneumonidae).

The diverse genus Ophion is almost entirely undescribed in the Nearctic region. In this paper we define the Ophion scutellaris species group. This species group is well-supported by analysis of DNA (ITS2, COI, and 28S D2-D3) and morphology. It includes the Palearctic species Ophion scutellaris and the Nearctic species Ophion idoneus. An integrative analysis of DNA, geometric wing morphometrics, classical morphometrics and qualitative morphology indicates that this species group contains a minimum of seven species in North America, although the full diversity of the group has likely not been sampled. Ophion clave Schwarzfeld, sp. n., Ophion aureus Schwarzfeld, sp. n., Ophion brevipunctatus Schwarzfeld, sp. n., Ophion dombroskii Schwarzfeld, sp. n., Ophion keala Schwarzfeld, sp. n. and Ophion importunus Schwarzfeld, sp. n. are described, and a key to the known Nearctic species of the Ophion scutellaris group is provided.

Sexual dimorphism in Sturnira lilium (Chiroptera, Phyllostomidae): can pregnancy and pup carrying be responsible for differences in wing shape?

Competition is one of the most cited mechanisms to explain secondary sexual dimorphism in animals. Nonetheless, it has been proposed that sexual dimorphism in bat wings is also a result of adaptive pressures to compensate additional weight caused by fetus or pup carrying during the reproductive period of females. The main objective of this study is to verify the existence of sexual dimorphism in Sturnira lilium wings. We employed geometric morphometrics techniques using anatomical landmarks superimposition to obtain size (Centroid Size) and shape variables of wings, which were reduced by Linear Discriminant Analysis (LDA). We also employed classical morphometrics using wing length measurements to compare efficiency between these two morphometric approaches and make comparisons using wing area measurements. LDA indicated significant differences between wing shapes of males and females, with 91% (stepwise classification) and 80% (leave-one-out cross validation) of correct classification. However, the size variable obtained did not contribute to such classifications. We have observed larger areas in female wings, but we found no differences in wing length measurements and no allometric effects in wing length, shape and area measurements. Interestingly, our study has provided evidences of morphological differences where classical morphometrics have failed. LDA and area measurements analyses revealed that females have a different area distribution in distinct portions of the wing, with wider dactylopatagia and plagiopatagia, and wingtips more triangular than males. No differences in body length or relative wing length were observed between the sexes, but pregnant females have more body weight than non-pregnant females and males. Our findings suggest that sexual dimorphism in the wing shape of S. lilium is probably related to the increase in flight efficiency of females during reproductive period. It decreases wing loading in specific portions of the wing and reduces energy cost to maintain a faster and maneuverable flight.

Shape Variation in Aterian Tanged Tools and the Origins of Projectile Technology: A Morphometric Perspective on Stone Tool Function

BackgroundRecent findings suggest that the North African Middle Stone Age technocomplex known as the Aterian is both much older than previously assumed, and certainly associated with fossils exhibiting anatomically modern human morphology and behavior. The Aterian is defined by the presence of ‘tanged’ or ‘stemmed’ tools, which have been widely assumed to be among the earliest projectile weapon tips. The present study systematically investigates morphological variation in a large sample of Aterian tools to test the hypothesis that these tools were hafted and/or used as projectile weapons.Methodology/Principal FindingsBoth classical morphometrics and Elliptical Fourier Analysis of tool outlines are used to show that the shape variation in the sample exhibits size-dependent patterns consistent with a reduction of the tools from the tip down, with the tang remaining intact. Additionally, the process of reduction led to increasing side-to-side asymmetries as the tools got smaller. Finally, a comparison of shape-change trajectories between Aterian tools and Late Paleolithic arrowheads from the North German site of Stellmoor reveal significant differences in terms of the amount and location of the variation.Conclusions/SignificanceThe patterns of size-dependent shape variation strongly support the functional hypothesis of Aterian tools as hafted knives or scrapers with alternating active edges, rather than as weapon tips. Nevertheless, the same morphological patterns are interpreted as one of the earliest evidences for a hafting modification, and for the successful combination of different raw materials (haft and stone tip) into one implement, in itself an important achievement in the evolution of hominin technologies.

Discrimination of Eubazus (Hymenoptera, Braconidae) sibling species using geometric morphometrics analysis of wing venation

Abstract Complexes of sibling and cryptic species are encountered frequently in parasitic Hymenoptera. Geometric morphometrics is a useful tool to detect minimal morphological variations, which often are undetectable by traditional morphological studies and even by classical morphometric approaches. We applied geometric morphometrics to wing venation to assess a complex case of sibling species in the genus Eubazus (Hymenoptera, Braconidae), parasitoids of conifer bark weevils of the genus Pissodes (Coleoptera, Curculionidae). The results and methods were compared with previous taxonomic studies on the same species, involving classical multivariate morphometrics, isoenzyme analyses, cross‐mating experiments and biological observations. Geometric morphometrics confirmed the previous division into four distinct species. However, this approach enabled the four species to be separated simultaneously, with a reliability of 98.6% for well‐classified females and 93.1% for males. A similar result in previous studies was obtained only by combining isoenzyme analyses and several canonical variate analyses, including many morphometric characters. Furthermore, measurements of wing venation were less time‐consuming, more reliable and required less prior knowledge of braconid taxonomy than the measurements needed for the classical morphometrics methods. Geometric morphometrics was used also to test the effect of host species on wing shape. Several female populations of Eubazus semirugosus originating from three different Pissodes spp. were compared. Significant differences were found in wing shape between conspecific Eubazus from different host species. The results are discussed in relation to reproductive isolation and genetic flow between the four species.

Geometric morphometrics as a tool for understanding Dactylorhiza (Orchidaceae) diversity in European Russia

Geometric morphometric techniques were employed to assess the diversity of lip shapes (305 samples from 83 populations) in flowers of European Russian Dactylorhiza (Orchidaceae: Orchidinae). We found significant agreement between the results from geometric morphometrics, classic morphometrics and the distribution of certain nuclear DNA markers. The lip shapes from Arctic Dactylorhiza samples occupied an intermediate position between D. maculata and D. fuchsii samples from Central Russia, supporting a hybrid origin of ‘northern tetraploids’. Lip shapes of the taxonomically controversial allotetraploid D. baltica were found to form a distinct group, with members having definite relationships with diploid D. incarnata samples from the same localities, indicating either their local origin or introgression with D. incarnata . In addition to demonstrating the value of geometric morphometric methods in studies of plant taxonomy and hybridization, we suggest future applications designed to explore pollinator-driven directional selection, developmental constraints and fluctuating asymmetry. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 1‐12.

A new early Holocene human skeleton from Brazil: implications for the settlement of the New World

Increasing skeletal evidence from the U.S.A., Mexico, Colombia, and Brazil strongly suggests that the first settlers in the Americas had a cranial morphology distinct from that displayed by most late and modern Native Americans. The Paleoamerican morphological pattern is more generalized and can be seen today among Africans, Australians, and Melanesians. Here, we present the results of a comparative morphological assessment of a late Paleoindian/early archaic specimen from Capelinha Burial II, southern Brazil. The Capelinha skull was compared with samples of four Paleoindian groups from South and Central America and worldwide modern groups from W.W. Howells' studies. In both analyses performed (classical morphometrics and geometric morphometrics), the results show a clear association between Capelinha Burial II and the Paleoindians, as well as Australians, Melanesians, and Africans, confirming its Paleoamerican status.