North American Black Research Articles

Asymmetric Hybridization and Sex-Biased Gene Flow Between Eastern Spot-Billed Ducks (Anas Zonorhyncha) and Mallards (A. Platyrhynchos) in the Russian Far East

AbstractThe Eastern Spot-billed Duck (Anas zonorhyncha) historically was rare in the southern Russian Far East. However, during the last 60–70 years, its breeding range in East Asia has expanded northwest; Eastern Spot-billed Ducks are breeding increasingly within the range of Mallards (A. platyrhynchos). We collected 120 Eastern Spot-billed Ducks and Mallards from Primorye, Russia, and sequenced 666–667 base pairs (bp) of the maternally inherited mitochondrial DNA (mtDNA) control region and 255 bp of the ornithine decarboxylase intron six (ODC6). Control region and ODC-6 allele sequences revealed two divergent groups of haplotypes and alleles that differ by 1.5% and 2.0%, respectively, and correspond to Avise et al.'s (1990) group A and B mtDNA haplotypes. Group A mtDNA haplotypes occurred in 22 Eastern Spot-billed Ducks and 78 Asian Mallards, and group B haplotypes occurred in 14 Eastern Spot-billed Ducks and 4 Asian Mallards. Moreover, the group B haplotypes that we observed predominantly in Eastern Spot-billed Ducks (i.e. group SB) were monophyletic and diverged by 2–16 substitutions from group B haplotypes previously sequenced from 241 Mottled (A. fulvigula), American Black (A. rubripes), and Mexican ducks (A. diazi), and from North American Mallards. In contrast, type 1 and 2 ODC-6 allele frequencies for Eastern Spot-billed Ducks and Mallards did not differ, but heterozygosity for the former was greater than expected under Hardy-Weinberg equilibrium. Our analysis is the first to document the existence of two divergent haplotype and allele lineages (group A and B, type 1 and 2) in Asian mallard species and suggests that Eastern Spot-billed Ducks are more closely related to North America's Mottled, American Black, and Mexican ducks than they are to Mallards, which occur sympatrically in East Asia. Our data are consistent with the hypothesis that Eastern Spot-billed Ducks and Mallards have hybridized extensively in the Russian Far East. If so, apparent differences in group A and B mtDNA haplotype ratios, effective populations sizes, and migration rates indicate that many more male Eastern Spot-billed Ducks mated with female Mallards and more Eastern Spot-billed Ducks received ODC-6 alleles from Mallards than vice versa. We hypothesize that those differences reflect strong female natal-site fidelity and high levels of male dispersal, and that Mallards significantly outnumber Eastern Spotbilled Ducks in Primorye. Excess heterozygosity in Eastern Spot-billed Ducks (and in Mallards to a lesser extent) is probably maintained by ongoing emigration of Eastern Spot-billed Ducks and Mallards from areas of allopatry outside the Primorye region, where Eastern Spot-billed Ducks and Mallards are predicted to possesses genotypic frequencies historically diagnostic of each species.

ASYMMETRIC HYBRIDIZATION AND SEX-BIASED GENE FLOW BETWEEN EASTERN SPOT-BILLED DUCKS (ANAS ZONORHYNCHA) AND MALLARDS (A. PLATYRHYNCHOS) IN THE RUSSIAN FAR EAST

The Eastern Spot-billed Duck (Anas zonorhyncha) historically was rare in the southern Russian Far East. However, during the last 60–70 years, its breeding range in East Asia has expanded northwest; Eastern Spot-billed Ducks are breeding increasingly within the range of Mallards (A. platyrhynchos). We collected 120 Eastern Spot-billed Ducks and Mallards from Primorye, Russia, and sequenced 666–667 base pairs (bp) of the maternally inherited mitochondrial DNA (mtDNA) control region and 255 bp of the ornithine decarboxylase intron six (ODC6). Control region and ODC-6 allele sequences revealed two divergent groups of haplotypes and alleles that differ by 1.5% and 2.0%, respectively, and correspond to Avise et al.'s (1990) group A and B mtDNA haplotypes. Group A mtDNA haplotypes occurred in 22 Eastern Spot-billed Ducks and 78 Asian Mallards, and group B haplotypes occurred in 14 Eastern Spot-billed Ducks and 4 Asian Mallards. Moreover, the group B haplotypes that we observed predominantly in Eastern Spot-billed Ducks (i.e. group SB) were monophyletic and diverged by 2–16 substitutions from group B haplotypes previously sequenced from 241 Mottled (A. fulvigula), American Black (A. rubripes), and Mexican ducks (A. diazi), and from North American Mallards. In contrast, type 1 and 2 ODC-6 allele frequencies for Eastern Spot-billed Ducks and Mallards did not differ, but heterozygosity for the former was greater than expected under Hardy-Weinberg equilibrium. Our analysis is the first to document the existence of two divergent haplotype and allele lineages (group A and B, type 1 and 2) in Asian mallard species and suggests that Eastern Spot-billed Ducks are more closely related to North America's Mottled, American Black, and Mexican ducks than they are to Mallards, which occur sympatrically in East Asia. Our data are consistent with the hypothesis that Eastern Spot-billed Ducks and Mallards have hybridized extensively in the Russian Far East. If so, apparent differences in group A and B mtDNA haplotype ratios, effective populations sizes, and migration rates indicate that many more male Eastern Spot-billed Ducks mated with female Mallards and more Eastern Spot-billed Ducks received ODC-6 alleles from Mallards than vice versa. We hypothesize that those differences reflect strong female natal-site fidelity and high levels of male dispersal, and that Mallards significantly outnumber Eastern Spotbilled Ducks in Primorye. Excess heterozygosity in Eastern Spot-billed Ducks (and in Mallards to a lesser extent) is probably maintained by ongoing emigration of Eastern Spot-billed Ducks and Mallards from areas of allopatry outside the Primorye region, where Eastern Spot-billed Ducks and Mallards are predicted to possesses genotypic frequencies historically diagnostic of each species.

Phenotypic Variation in Skull Size and Shape Between Newfoundland and Mainland Populations of North American Black Bears, <em>Ursus americanus</em>

It is well recognized that differences in environmental selection pressures among populations can generate phenotypic divergence in a suite of morphological characteristics and associated life history traits. Previous analysis of mitochondrial DNA and body size have suggested that Black Bears (Ursus americanus) inhabiting the island of Newfoundland represent a different subspecies or ecotype from mainland populations. Assuming that body size covaries positively with skull size, we predicted that skull size would be greater for bears on the island than the mainland, and the distribution of size-related shape components in multivariate space should show a distinct separation between Newfoundland and mainland populations. Measurements of 1080 specimens from Newfoundland, Alberta, New York, and Quebec did not provide unequivocal support for our prediction that skull size in Newfoundland bears would be larger than bears from the mainland populations. After removing ontogenetic effects of skull size, between-population variation in skull shape was greater in females than males, and the analysis significantly separated Newfoundland bears from mainland populations. Explanations for this pattern are numerous, but currently remain hypothetical. Limited covariation between skull size and body size suggests that genetic traits regulating the size of Black Bear skulls are more heritable (i.e., less influenced by environmental selection pressures) than characteristics affecting body size. We hypothesize that if gape size does not limit prey size in solitary terrestrial carnivores, large degrees of among-population variation in body size should be coupled with little covariation in skull size. In general, sexual dimorphism in skull size and shape was marginal for the phenotypic characters measured in our study. We believe that sexual dimorphism in skull size in Black Bears is primarily driven by intrasexual selection in males for increased gape size display, while similarity in skull shape between sexes is associated with the constraints of a temporally-selective, but similar diet.

Some Of These Days

Thanks to the kind cooperation of Mrs. Elise Harding-Davis, director of the North American Black Historical Museum and Cultural Centre, we are able to reproduce the score of this famous melody which features so prominently in Sartre’s Nausea. This museum is located in Amherstburg, Ontario, some thirty kilometers southwest of the Ambassador Bridge which links Detroit, Michigan with Windsor, Ontario. Shelton Brooks, who composed the melody in 1910, was a descendent of black slaves who made their way to freedom by way of “the underground railway” and settled in Southwestern Ontario.

Caradocian chitinozoans from the Central Basin, Tennessee

Chitinozoans occur in low numbers and diversity in all formations of the Caradocian Stones River and Nashville Groups of the Central Basin, Tennessee. Sixteen species have been found in the interval studied: Belonechitina micracantha, B. robusta, B. seriespinosa, B. wesenbergensis, Calpichitina lata, Conochitina elegans, C. minnesotensis, Cyathochitina kuckersiana, Desmochitina minor, Lagenochitina cf. L. baltica, Pistillachitina pistillifrons, Rhabdochitina magna, R. turgida, R. usitata, Sphaerochitina actonica and Spinachitina multiradiata. On the basis of the chitinozoans present, the lower part of the Stones River Group is correlated to the North American Black Riveran Stage interval (British lower Caradocian Series). The upper part of the Stones River Group and the Nashville Group are correlated to the Black Riveran-Edenian interval (lower to middle Caradocian).

Caradocian chitinozoans from the Central Basin, Tennessee

Chitinozoans occur in low numbers and diversity in all formations of the Caradocian Stones River and Nashville Groups of the Central Basin, Tennessee. Sixteen species have been found in the interval studied: Belonechitina micracantha, B. robusta, B. seriespinosa, B. wesenbergensis, Calpichitina lata, Conochitina elegans, C. minnesotensis, Cyathochitina kuckersiana, Desmochitina minor, Lagenochitina cf. L. baltica, Pistillachitina pistillifrons, Rhabdochitina magna, R. turgida, R. usitata, Sphaerochitina actonica and Spinachitina multiradiata. On the basis of the chitinozoans present, the lower part of the Stones River Group is correlated to the North American Black Riveran Stage interval (British lower Caradocian Series). The upper part of the Stones River Group and the Nashville Group are correlated to the Black Riveran-Edenian interval (lower to middle Caradocian).

North American Black Bear mtDNA Phylogeography: Implications for Morphology and the Haida Gwaii Glacial Refugium Controversy

North American Black Bear mtDNA Phylogeography: Implications for Morphology and the Haida Gwaii Glacial Refugium Controversy

Ecology and Behaviour of North American Black Bears (Home Ranges, Habitat and Social Organization)

Covering the ecology and behaviour of North American black bears, this volume discusses such topics as: home ranges and home range estimators; predicting habitat quality and use of home ranges; food abundance and variation in home range size; and territories and home ranges.

A comparative and correlational study of the cranial base in North American blacks

The purpose of this investigation was to compare the cranial bases of blacks and whites in regard to length, angulation, and flexure, and to determine what proportion of the differences in facial measurements can be explained by the variability seen in the cranial base. Standardized cephalograms of 100 native-born North American black adults were traced, analyzed, and compared with white values. The measurements selected depicted dependency and independency from the cranial base. Mean differences between the races and the sexes were assessed with the Student's t test. Models of linear regression between the cranial base measurements and all other parameters were computed for both sexes and correlation coefficient values calculated. This study established that the length of the cranial base in North American blacks is significantly shorter from that of whites. A strong biologic relationship was demonstrated between the length of the cranial base of blacks and their denture bases, the palatal, and occlusal planes. The data suggest that most of the cephalometric differences between blacks and whites are not simply anatomic for measurements using sella nasion as their reference plane.

Vertical dimensional changes of the lips following four first premolar extractions in the North American Black

Vertical dimensional changes of the lips following four first premolar extractions in the North American Black

The North American Black Duck (Anas rubripes): A Case History of 28 Years of Failure in American Wildlife Management

The North American Black Duck (Anas rubripes): A Case History of 28 Years of Failure in American Wildlife Management

Autoantibodies and immunoglobulin allotypes in healthy North American Blacks of different age groups

A population of 291 healthy North American Black subjects of different ages was studied for immunoglobulin (Ig) allotypes and the prevalence of autoantibodies, to determine possible associations between Ig allotypes and age, autoantibodies and age, and Ig allotypes and autoantibodies. Indirect immunofluorescence was used to detect anti-gastric parietal cell, anti-smooth muscle, anti-thyroid microsomal, anti-nuclear, and anti-mitochondrial antibodies. The sera were typed for the Ig allotypes Gm(1, 2, 3, 5, 6, 13, 14, 17, and 21) and Km(1) with a hemagglutination-inhibition assay. A significant association between advanced age and an increased prevalence of anti-nuclear antibodies was observed in females. There was no significant association between Ig allotypes and the autoantibodies tested. The results suggest that Ig allotypes are not involved in the development of autoantibodies in healthy Blacks.

Factor B polymorphism in North American blacks: study of a new variant Bf F1.35.

A "new" variant of the factor B (Bf) system has been found in the serum of three individuals of a North American Black family. This variant migrates faster than Bf F1 and has been designated Bf F1.35 on account of the relative electrophoretic mobility using reference Bf typed sera. This new factor B variant (F1.35) was found to be functionally active using a specific hemolytic overlay technique and was inherited on an HLA-A28;Bw35;C4 A3,B1;C2C;DR3;GLO2 haplotype.

An evaluation of the soft-tissue facial profile in the North American black woman

I t has become apparent within the past several years that significant variations do occur among and between individuals of different racial origins. Reports of interracial and intraracial investigations concerning anthropologic, physiologic, psychologic, cultural, genealogic, and various other areas of study are becoming increasingly prevalent in the literature. Among the various races that have been investigated, the black race has been examined to a moderate degree, originally through early anthropologic research and more recently through cultural and genealogic investigations. In the field of orthodontics, the North American black has been examined primarily through radiologic, photographic, and clinical methods, including evaluations of dentoalveolar study models. Of these studies, it is striking that there exists very little formal information fundamentally concerned with an evaluation of facial esthetics in the North American black. With the increasing number of North American blacks seeking professional treatment from the orthodontist, the oral and maxillofacial surgeon, the plastic and reconstructive surgeon, the otolaryngologist, and the maxillofacial prosthodontist, it has become apparent that there is a need to determine what constitutes a pleasing and/or a nonpleasing face for members of the North American black population. This information could become an integral part of the diagnostic armamentarium for these and other professionals who deal both directly and indirectly with changing the natural contours and profile outline of the face. The purpose of this study is to evaluate the responses of several white and black members of the orthodontic specialty to preselected soft-tissue facial profile outlines in the North American black woman. Specific questions examined in this study include: 1. What is the opinion among orthodontists of what is considered a pleasing and/or a nonpleasing facial profile for the adult North American black female? 2. Do profile preferences differ according to the race of the orthodontist? 3. Is there a significant relation between profile preferences and certain facial characteristics and patterns? 4. Upon what criteria are these profile preferences based?

Soft tissue facial profile of North American blacks: A self-assessment

The purpose of the study was to gain insight into the preferences and opinions of North American blacks regarding black facial profiles in general and their own facial profile in particular. Lateral facial photographs of I53 North American black women of varying social and educational backgrounds between the ages of 18 and 4 I were shown to fourteen professionals (orthodontists, oral surgeons, and general dentists) of whom seven were black and seven were white. Their task was to separate the 153 photographs into ten categories. In addition, the fourteen judges were asked to select the profile most representative of each of the ten categories. Interand intrajudge reliability was shown to be exceedingly high in these categorizations. These ten representative profiles, randomly arranged, plus a questionnaire were presented to 224 North American black women of varying educational and social backgrounds, ranging in age from 18 to 4 I years. Subjects were asked to indicate which profile was most pleasing and which profile was least pleasing to them, which profile looked most like themselves, and their attitude toward their own profile. The profile type of each of the 224 respondents also was noted so that the degree of correlation between respondents’ judgments and their own profile type could be calculated. A significant majority of respondents preferred the straighter facial profiles; this preference was consistent among all age groups. A significant degree of disfavor was registered for the “Class II deep” extremely bimaxillary protrusive profile and the “Class III” profile types. Respondents generally were unsuccessful in recognizing their own profile types among the ten pictured profiles, and a substantial number of respondents desired no change in their profiles, regardless of their own profile type.

A Revision of the North American Black Cherries (Prunus Serotina Ehrh., and Relatives)

A Revision of the North American Black Cherries (Prunus Serotina Ehrh., and Relatives)