bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microsatellite determination of male reproductive success in a natural population of the territorial ornate dragon lizard, Ctenophorus ornatus
Authors: Lebas N. R. 
Published: March 2003

AbstractIt is now evident that the genetic mating system can be very different to the observed mating system. However, it is less well known what makes particular individuals more (or less) successful than expected from the observed system. In this study the observed territorial structure of a field population of the agamid lizard, Ctenophorus ornatus, was compared with the mating system as evidenced by microsatellite parentage assignment. This study also investigated whether any male traits predicted reproductive success. Sixty‐five per cent of clutches were sired at least partially by a male other than the main territory‐holding male and 35% of clutches were sired by a male with no overlap of the female’s territory. Multiple paternity was moderately frequent at 25% of clutches. Male chest patch size predicted territory size and the number of females in the territory, but did not predict reproductive success. Instead, male head depth and body size were independently related to the number of offspring sired. As male head depth also predicted the number of females in a territory, these males are likely to be gaining increased reproductive success as a consequence of the higher number of females in their territories. Larger body size males, however, did not have a greater number of females in their territory and instead had more extra‐territorial copulations. Whether these extra‐territorial copulations are due to female choice or success in male competition is unknown.
Evidence for broadscale introgressive hybridization between two redfish (genusSebastes) in the North‐west Atlantic: a rare marine example
Authors: Roques SÉverine , SÉvigny Jean‐Marie , Bernatchez Louis 
Published: March 2003

AbstractThe evolutionary importance of introgressive hybridization has long been recognized by plant evolutionists, and there is now a growing recognition for its potential role in animals as well. Detailed empirical investigations of this evolutionary process, however, are still lacking in many animal groups, particularly in the marine environment. Using integrated microsatellite DNA data (eight loci analysed over 803 individuals representing 17 sampling locations) and multivariate statistical procedures (principal component, factorial correspondence and admixture proportion analyses), we: (i) provide a detailed dissection of the dynamics of introgressive hybridization betweenSebastes fasciatusandS. mentella, two economically important redfishes from the North‐west Atlantic; and (ii) infer the factors potentially involved in the maintenance of the hybrid zone observed in the gulf of St. Lawrence and south of Newfoundland. This study provided one of the rare examples of extensive introgressive hybridization in the ocean, and highlighted the predominant role of this process in shaping the extent of genetic diversity, interspecific differences and population structuring among redfishes from the North‐west Atlantic. The extensive (average rate of introgression = 15%) but geographically circumscribed and asymmetrical pattern of introgressive hybridization, the sympatric persistence of two reproductively isolated introgressed groups, the differential patterns of linkage disequilibrium among samples, and the maintenance of genetic integrity of both species outside the defined zone of introgression despite high potential for gene flow, all implicated selection in promoting and maintaining the observed pattern of introgression.
Multiple paternity and mating patterns in the American alligator, Alligator mississippiensis
Authors: Davis Lisa M. , Glenn Travis C. , Elsey Ruth M. , Dessauer Herbert C. , Sawyer Roger H. 
Published: March 2003

AbstractEggs were sampled from 22 wild American alligator nests from the Rockefeller Wildlife Refuge in south‐west Louisiana, along with the females guarding the nests. Three nests were sampled in 1995 and 19 were sampled in 1997. Females and offspring from all clutches were genotyped using five polymorphic microsatellite loci and the three nests from 1995 were also genotyped using one allozyme locus. Genotypes of the hatchlings were consistent with the guarding females being the mothers of their respective clutches. Multiple paternity was found in seven of the 22 clutches with one being fathered by three males, and the remaining six clutches having genotypes consistent with two males per clutch. Paternal contributions of multiply sired clutches were skewed. Some males sired hatchlings of more than one of the 22 clutches either as one of two sires of a multiple paternity clutch, as the sole sire of two different clutches, or as the sole sire of one clutch and one of two sires of a multiply sired clutch. There was no significant difference between females that had multiple paternity clutches and those that had singly sired clutches with respect to female total length (P = 0.844) and clutch size (P = 0.861). Also, there was no significant correlation between genetic relatedness of nesting females and pairwise nest distances (r2 = 0.003, F1,208 = 0.623, P = 0.431), indicating that females in this sample that nested close to one another were no more related than any two nesting females chosen at random. Eleven mutations were detected among hatchlings at the five loci over the 22 clutches. Most of these mutations (eight of 11) occurred at Amiµ‐17, the only compound microsatellite locus of the five used in this study, corresponding to a mutation rate of 1.7 × 10−3. Finally, most of the mutations (82%) were homoplasious, i.e., mutating to an allelic state already present in this Louisiana population.
Noninvasive paternity assignment in Gombe chimpanzees
Authors: Constable Julie L. , Ashley Mary V. , Goodall Jane , Pusey Anne E. 
Published: March 2003

AbstractThe relative success of chimpanzee male mating strategies, the role of male dominance rank and the success of inbreeding avoidance behaviour can only be assessed when paternities are known. We report the probable paternities of 14 chimpanzees included in a long‐term behavioural study of chimpanzees (Pan troglodytes schweinfurthii) at Gombe National Park, Tanzania. DNA samples were collected noninvasively from shed hair and faeces and genotyped using 13–16 microsatellite loci characterized in humans. All 14 offspring could be assigned to fathers within the community. While there is a positive relationship between male rank and reproductive success, we demonstrate that a range of male mating strategies (possessiveness, opportunistic mating and consortships) can lead to paternity across all male ranks. Several adult females were at risk of breeding with close male relatives. Most successfully avoided close inbreeding but in one case a high‐ranking male in the community mated with his mother and produced an offspring. In contrast to recent data on chimpanzees (P. t. verus) from the Taï forest, Côte d’Ivoire, no evidence of extra‐group paternity was observed in our study. Reanalysis of Taï data using a likelihood approach casts doubt on the occurrence of extra‐group paternity in that community as well.
High levels of extra‐pair paternity in an isolated, low‐density, island population of tree swallows (Tachycineta bicolor)
Authors: Conrad K. F. , Johnston P. V. , Crossman C. , Kempenaers B. , Robertson R. J. , Wheelwright N. T. , Boag P. T. 
Published: March 2003

AbstractMolecular genetic studies have suggested that apparently nonbreeding males (‘floaters’) may account for a significant proportion of extra‐pair paternity (EPP) in avian populations. Attempts to determine the influence of breeding density on EPP are therefore confounded by the presence of a subpopulation of floaters whose numbers are difficult to estimate. To study EPP in a tree swallow (Tachycineta bicolor) population with few floaters, we chose a nestbox grid on an island with an excess of available breeding sites and very few floaters. We obtained DNA samples from 13 complete families and performed DNA profiling on them using four microsatellite loci. For comparison, we also obtained a sample of 58 extra‐pair young (EPY) from a mainland population typed at five microsatellite loci. Paternity assignments among resident males in both populations were made using the microsatellite profiles and a likelihood‐based statistical method. Of the 67 island nestlings typed, we found 37 (55%) nestlings from 11 (85%) different nests that were EPY. The proportion of nestlings that were EPY and the proportion of broods containing EPY did not differ significantly between island and mainland populations studied previously. There was no significant difference between island and mainland populations in the proportion of extra‐pair paternities assigned among neighbouring resident males. Male breeding density does not appear to affect the ability of female tree swallows to obtain extra‐pair fertilizations, at least over the range of densities studied so far. The rate of EPP has remained remarkably consistent over many years, studies and populations implying an important role of active female choice in determining EPP.
Mating patterns, relatedness and the basis of natal philopatry in the brown long‐eared bat,Plecotus auritus
Authors: Burland T. M. , Barratt E. M. , Nichols R. A. , Racey P. A. 
Published: March 2003

AbstractThe brown long‐eared bat,Plecotus auritus, is unusual among temperate zone bats in that summer maternity colonies are composed of adult males and females, with both sexes displaying natal philopatry and long‐term association with a colony. Here, we describe the use of microsatellite analysis to investigate colony relatedness and mating patterns, with the aim of identifying the evolutionary determinants of social organization inP. auritus. Mean colony relatedness was found to be low (R = 0.033 ± 0.002), with pairwise estimates ofRwithin colonies ranging from −0.4 to 0.9. The proportion of young fathered by males in their own colony was investigated using a Bayesian approach, incorporating parameters detailing the number of untyped individuals. This analysis revealed that most offspring were fathered by males originating from a different colony to their own. In addition, we determined that the number of paternal half‐sibs among cohorts of young was low, inferring little or no skew in male reproductive success. The results of this study suggest that kin selection cannot account for colony stability and natal philopatry inP. auritus, which may instead be explained by advantages accrued through the use of familiar and successful roost sites, and through long‐term associations with conspecifics. Moreover, because the underlying causes of male natal dispersal in mammals, such as risk of inbreeding or competition for mates, appear to be avoided via extra‐colony copulation and low male reproductive skew, bothP. auritusmales and females are able to benefit from long‐term association with the natal colony.
Phylogeography of the African buffalo based on mitochondrial and Y‐chromosomal loci: Pleistocene origin and population expansion of the Cape buffalo subspecies
Authors: Van Hooft W. F. , Groen A. F. , Prins H. H. T. 
Published: March 2003

AbstractPopulation genetics and phylogeography of the African buffalo (Syncerus caffer) are inferred from genetic diversity at mitochondrial D‐loop hypervariable region I sequences and a Y‐chromosomal microsatellite. Three buffalo subspecies from different parts of Africa are included. Nucleotide diversity of the subspecies Cape buffalo at hypervariable region I is high, with little differentiation between populations. A mutation rate of 13–18% substitutions/million years is estimated for hypervariable region I. The nucleotide diversity indicates an estimated female effective population size of 17 000–32 000 individuals. Both mitochondrial and Y‐chromosomal diversity are considerably higher in buffalo from central and southwestern Africa than in Cape buffalo, for which several explanations are hypothesized. There are several indications that there was a late middle to late Pleistocene population expansion in Cape buffalo. This also seems to be the period in which Cape buffalo evolved as a separate subspecies, according to the net sequence divergence with the other subspecies. These two observations are in agreement with the hypothesis of a rapid evolution of Cape buffalo based on fossil data. Additionally, there appears to have been a population expansion from eastern to southern Africa, which may be related to vegetation changes. However, as alternative explanations are also possible, further analyses with autosomal loci are needed.
Extensive exchange of fungal cultivars between sympatric species of fungus‐growing ants
Authors: Green A. M. , Mueller U. G. , Adams R. M. M. 
Published: March 2003

AbstractFungal cultivars of fungus‐growing ants (Attini, Formicidae) are carried by dispersing queens from parent to offspring nest. This vertical cultivar transmission between generations is thought to result in long‐term ant‐fungus coevolution and selection for beneficial cultivar traits that maximize harvests and thus colony productivity. In contrast to this traditional view of vertical cultivar transmission, frequent horizontal cultivar transmission between ant species is implicated by a phylogenetic analysis of 72 cultivars propagated by two fungus‐growing ant species coexisting sympatrically in central Panama. The two ant species are specialized on the same group of closely related cultivars, but in six of 12 cultivar clades identifiable within this group, cultivars from both ant species were united in the same clade. Five of these ‘mixed’ clades were supported by bootstrap values of about 90% or higher. In one instance, colonies from the two ant species cultivated the same, genetically identical, cultivar clone. These phylogenetic patterns indicate that: (i) cultivar exchanges between the two ant species occur routinely throughout ecological time; and that (ii) coevolutionary processes between ants and their fungi are more diffuse than previously assumed. Because the two ant species are specialized on a narrow group of closely related cultivars that they regularly exchange among each other, but not with other sympatric ant species, cultivar exchanges are constrained, most likely, by ant preferences for their own cultivar group or by stringent selection against transitions of ant lineages to distantly related cultivars.
Population genetic subdivision in the New Zealand greenshell mussel (Perna canaliculus) inferred from single‐strand conformation polymorphism analysis of mitochondrial DNA
Authors: Apte S. , Gardner J. P. A. 
Published: March 2003

AbstractSingle‐strand conformation polymorphism (SSCP) analysis of the NADH IV region of the mitochondrial DNA (mtDNA) molecule in greenshell mussels (Perna canaliculus) indicated strong population genetic structuring in this endemic New Zealand species. A northern and a southern group were differentiated by frequency shifts in common haplotypes and by the occurrence of a unique southern haplotype at ≈ 20% frequency. This split occurred south of Cook Strait (the body of water between the North and the South Island) at ≈ 42° S latitude. Northern populations were less genetically diverse than southern populations and mussels from the west coast of the South Island were most distinct from northern mussels. We hypothesize that the unique haplotype VIII originated in the lower South Island, and that its spread northwards was obstructed by the opening of Cook Strait ≈ 15 000–16 000 years ago and the subsequent establishment of present‐day surface water circulation patterns in Greater Cook Strait. We suggest that present‐day strong tidal flows and turbulent mixing of water masses in Cook Strait, and intense up‐welling on the east and west coasts in this region, represent a barrier to gene flow between mussels located in the North Island and northern South Island vs. mussels in most of the South Island and Stewart Island.
Field experiments on the distributions of eggs of different phosphoglucomutase (PGM) genotypes in the yellow dung fly Scathophaga stercoraria (L.)
Authors: Ward Paul I. , Vonwil Judith , Scholte Ernst‐Jan , Knop Eva 
Published: March 2003

AbstractFemale yellow dung flies can, in the laboratory, influence the probability that stored sperm from different males are used to fertilize eggs. This matches offspring phosphoglucomutase genotypes to the environmental conditions in which the larvae will grow, increasing larval growth success. We conducted field experiments in which dung topology or shading conditions were controlled. The proportions of the five common phosphoglucomutase alleles in eggs laid in north‐facing slopes or in shaded conditions was related to their electrophoretic mobility. We suggest that females lay eggs of different genotypes, by appropriately choosing their fathers, in different places.
Mitochondrial DNA phylogeography and population history ofMelademadiving beetles on the Atlantic Islands and in the Mediterranean basin (Coleoptera, Dytiscidae)
Authors: Ribera I. , Bilton D. T. , Vogler A. P. 
Published: March 2003

AbstractThe phylogeny and population history ofMelademadiving beetles (Coleoptera, Dytiscidae) were examined using mitochondrial DNA sequence from 16S ribosomal RNA and cytochrome oxidase I genes in 51 individuals from 22 populations of the three extant species (M. imbricataendemic to the western Canary Islands,M. lanioendemic to Madeira andM. coriaceawidespread in the Western Mediterranean and on the western Canaries), using a combination of phylogenetic and nested clade analyses. Four main lineages are observed withinMeladema, representing the three recognized species plus Corsican populations ofM. coriacea. Phylogenetic analyses demonstrate the sister relationship of the two Atlantic Island taxa, and suggest the possible paraphyly ofM. coriacea. A molecular clock approach reveals that speciation within the genus occurred in the Early Pleistocene, indicating that the Atlantic Island endemics are not Tertiary relict taxa as had been proposed previously. Our results point to past population bottlenecks in all four lineages, with recent (Late‐Middle Pleistocene) range expansion in non‐CorsicanM. coriaceaandM. imbricata. Within the Canary Islands,M. imbricataseems to have independently colonized La Gomera and La Palma from Tenerife (although a colonization of La Palma from La Gomera cannot be discarded), andM. coriaceahas independently colonized Tenerife and Gran Canaria from separate mainland lineages. In the Mediterranean basin this species apparently colonized Corsica on a single occasion, relatively early in its evolutionary history (Early Pleistocene), and has colonized Mallorca recently on multiple occasions. On the only island whereM. coriaceaandM. imbricataare broadly sympatric (Tenerife), we report evidence of bidirectional hybridization between the two species.
Condition‐dependent sex allocation in a lek‐breeding wader, the ruff (Philomachus pugnax)
Authors: Thuman Katherine A. , Widemo Fredrik , Griffith Simon C. 
Published: March 2003

AbstractSex allocation theory predicts that females should bias the production of offspring towards the sex that will maximize maternal fitness. Here we demonstrate evidence for nonrandom sex allocation by female ruffs (Philomachus pugnax), at both the individual and population level in relation to female condition. At the population level, female condition varies significantly across 3 years and is mirrored by population sex ratio, such that in years when females are in poor condition the population offspring sex ratio is female‐biased, while in years when females are in better condition there was little or no bias. In the year when females were in overall poor condition, females in better condition produced more daughters. The same relationship is also revealed by comparing the sex ratios of individual females breeding in two consecutive years in different condition. As the condition of an individual female improves (across years) she tends to produce more female offspring. Although we have shown that, as in other birds, female condition is an important determinant of sex allocation, our results also suggest that such nonrandom allocation does not occur in every year, being particularly strong in a year when females, on average, are in poorer condition. We suggest that our results are consistent with the idea that skewing the sex ratio is likely to carry a cost to females and that it is adaptive only when the fitness differential between sons and daughters is sufficient to outweigh probable costs.
The recent evolutionary origin of the phenotypically novel amphipodHyalella montezumaoffers an ecological explanation for morphological stasis in a closely allied species complex
Authors: Witt Jonathan D. S. , Blinn Dean W. , Hebert Paul D. N. 
Published: March 2003

AbstractNumerous molecular studies have identified morphologically cryptic, freshwater invertebrate species, but have not suggested possible mechanisms for their phenotypic stasis. The amphipod crustacean genusHyalellacontains numerous morphologically cryptic species in theH. aztecacomplex, as well as a small number of morphologically very divergent, narrowly endemic taxa. One such taxon,Hyalella montezuma, is the sole planktonic filter‐feeder within the North American amphipod fauna, and is known only from Montezuma Well, a fishless travertine spring mound in Arizona, USA. In this study, we conduct a phylogenetic analysis of mtDNA sequence data using likelihood, Bayesian and cladistic approaches to determine both the relationship ofH. montezumato theH. ‘azteca’ species complex, and to ascertain if its morphological and ecological differentiation have been comparatively recent. The results show thatH. montezumahas a very close phylogenetic affiliation with one lineage in theH. aztecacomplex, indicating that its origin has been recent. We present evidence suggesting that fish predation is an important ecological factor, which constrains morphological and ecological diversification within the genusHyalella, and that Montezuma Well has provided a relaxation on this constraint.
Extinction‐colonization dynamics structure genetic variation of spotted sunfish (Lepomis punctatus) in the Florida Everglades
Authors: Mcelroy T. C. , Kandl K. L. , Garcia J. , Trexler J. C. 
Published: March 2003

AbstractThe population genetics of aquatic animals in the Florida Everglades may be strongly influenced by extinction and colonization dynamics. We combined analyses of allozyme and microsatellite loci to test the hypothesis that two levels of population structure are present for spotted sunfish (Pisces: Centrarchidae: Lepomis punctatus) inhabiting the Everglades. We hypothesized that annual cycles of marsh dry‐down increase local‐scale genetic variation through a process of local extinction and colonization; we hypothesized that barriers to gene flow by levee/canal systems create a second, regional level of genetic variation. In 1996 and 1997, we sampled spotted sunfish from 11 Everglades sites that were distributed in three regions separated by levees. We documented patterns of genetic variation at 7 polymorphic allozyme loci and 5 polymorphic microsatellite loci. Most genetic variation was present among local populations, according to both types of genetic markers. Furthermore, samples from marsh sites were heterogeneous, while those from canals were not. These data supported our hypothesis that dry‐down events and local population dynamics in the marsh have a significant effect on population genetic structure of spotted sunfish. We found no support for our hypothesis that water‐management structures superimpose a second level of genetic structure on this species, possibly because canals obscure historical structure by facilitating gene flow or because the complete canal system has been in place for fewer than 20 generations of this species. Our data suggests a continent‐island (canal‐marsh) structure of populations with high gene flow among regions and recurrent mixing in marshes from canal and creek habitats.