Probability Of Paternity Research Articles

Genetic typing with HUMTH01, HUMVWA31A and HUMFES/FPS short tandem repeat loci, D1S80 variable number tandem repeat locus and HLA-DQ alpha of recent and from XII-XIII centuries spongy bone.

The genetic analysis of ancient populations through DNA from bone remains, requires use of short sized loci that can be amplified by polymerase chain reaction (PCR) for which the short tandem repeat (STR) loci are most suitable. These techniques can also be applied to genetic identification in forensic casework. In this study three STR loci, HUMFES/FPS, HUMTH01, and HUMVWA31A, were selected to estimate their usefulness when applied to recent and ancient spongy bone DNA typing. In addition, loci D1S80 and HLA DQ alpha were also tested in the analysis of recent spongy bone DNA. The recent remains studied were constituted by ten spongy bone samples of postmortem material from one individual buried for 1 year. The ancient remains are composed by 8 spongy bone samples from the heads of left femurs from a XII-XIII Centuries Basque Country population. Adequate amplification and typing results could only be obtained with cetyltrimethyl ammonium bromide (CTAB)-extracted DNA, without any further purification after precipitation. Genotypes of the one year post-mortem material and those of his son and his wife were obtained at the D1S80, HLA-DQ alpha, and STR loci. In all these systems, no exclusion was observed, with a combined probability of paternity of 0.9997. This demonstrates the reliability of the obtained results. The genetic typing of HUMTH01 in spongy bone from the XII-XIII Centuries Basque Country individuals was also performed. This will allow the genetic analysis of ancient bone remains and therefore, to carry out evolutionary population studies.

Sperm competition in the sand lizard, Lacerta agilis

Abstract. Sperm competition between males will occur when more than one male successfully inseminates a single female and the viable sperm from different males compete for fertilization of that female's egg(s). The fertilization success of males may depend on at least two factors: the viability of sperm over time, and whether males can prevent other males from fertilizing eggs in subsequent copulations. In this study on the sand lizard, sperm did not survive in the female reproductive tract between ovulations, and sterilized males did not lower the probability of paternity for males in a second copulation occurring within 24 h. Using a genetic marker trait and DNA fingerprinting, we confirmed that multiple inseminations of different fully fertile males led to multiple paternity among offspring. The results provide evidence suggesting that neither mating order nor time between copulations has any impact on the reproductive success of first or last males.

Parental Role-Reversed Polyandry and Paternity

Parental Role-Reversed Polyandry and Paternity

Calculation of paternity probabilities from multilocus DNA profiles.

We describe a procedure for evaluation of paternity evidence from multi-locus DNA probe patterns. A computer program abstracts a "+/-" notation description from the multilocus profile and then calculates a paternity index based on observed phenotypic fragment frequencies. The biostatistical evaluation considers only bands found in the child and missing from the mother--a simplified approach that is at once robust and conservative. Mutations are of course taken into account. Particular features lending objectivity to the interpretation include computer reading and matching decisions, and specific recognition and statistical compensation for ambiguities ("faint orphans").

Paternity Investigation Among Known False Trios: ABO, Rh, MNSs, Kell, Duffy, Kidd, and HLA Systems

This paternity study was performed with trios in which the putative father was not the biological father (NBF), in order to evaluate adjustment of genetic markers employed to disclose non biological fathers for the population, and the biological meaning of likelihood of paternity in casework. All 923 generated trios had ABO, Rh, MNS, Kell and HLA systems tested; 372 of them also had Duffy and Kidd systems tested. The most powerful exclusion system was HLA, followed, in this order, by ABO, Rh, Duffy, MNSs, Kidd, and Kell. Taking into account the Indian/black/white historical miscegenation background in the population, an improvement in the performance of red blood cells as disclosers of non biological fathers could be achieved, if particular additional sera were used. In the group tested with seven different systems, direct exclusions were observed in 90.31%, and they were single system exclusions in 26.61%. In order to avoid the remote possibility of mutation, it is suggested that the number of used systems be increased. Indirect exclusions were verified in 8.87% and only 0.81% of NBF were not excluded at all. In this last group, probabilities of paternity were calculated and two values greater than 95% were obtained. To be able to accomplish the "visum et repertum" duty and to assist the court, the expert should equally emphasize: a) the probability of paternity of the alleged father and the possibility of finding an unexcluded NBF; b) the actual performance of systems used to uncover NBF, together with the probabilities of paternity of those who were not discovered; c) the previous referenced trend of probabilities of paternity of true and of non-biological fathers to cluster in distinct class intervals of likelihood of paternity.

Paternity displacement in the grasshopper Eyprepocnemis plorans

Three types of double crosses were carried out to investigate sperm competition in the grasshopper Eyprepocnemis plorans. Maximum likelihood estimation of paternity probability showed a high degree of second male sperm precedence (P2 = 90%). The results also showed that: (i) a single copulation may be enough for an efficient paternity displacement; (ii) males do not use sperm plugs, but they mate for a prolonged period of time to resist further copulation; and (iii) successive paternity displacements may be seen in the same female. The mechanisms controlling sperm competition in E. plorans, and the evolutionary implications of this phenomenon are discussed

Paternity by a seemingly infertile vasectomised man.

A case of failed vasectomy in a patient whose semen repeatedly showed no or only scant, nonmobile spermatozoa, was confirmed by paternity testing. The patient was vasectomized in December 1987. His semen tested negative for sperm 12 and 18 weeks afterwards. 28 months after surgery his wife's pregnancy was confirmed. His semen again tested negative for spermatozoa 2.5, 3. 3.5, and 5 years after surgery, and showed only a few nonmobile sperm from the spun deposit. Paternity tests included DNA profiling with 6 single locus DNA probes on the parents and child, as well as 19 conventional protein polymorphisms. These tests defined the probability of paternity as 99.999%. The patient's brother was excluded by 2 of the 5 DNA probes. Thus this is a highly improbable case of paternity by a man deemed infertile by normally accepted criteria.

Prenatal Paternity Testing Following Sexual Assault: A Novel Application of Forensic DNA Typing

A woman was sexually assaulted and subsequently learned that she was pregnant. She had consensual relations with her husband in the weeks preceding and following the assault, but could not exclude the possibility that the pregnancy resulted from the sexual assault. To resolve the issue of paternity, the DNA profiles of the victim and her husband were compared to that of a chorionic villus sample taken by biopsy at ∼ 11 weeks fetal gestation. The results were consistent with the victim's husband being the biological father of the fetus, with a genetic odds ratio in favour of paternity (P/) of 849 and 99.88% probability of paternity. This case demonstrates a novel application of forensic DNA typing to determine the paternity for pregnancies which may have resulted from sexual assault.

Application of DNA profiling to paternity testing during early pregnancy.

Four probes that recognize D2S44, D17S79, D4S163 and D18S27 loci, were used to produce DNA profiles of 8- to 10-week-old chorionic villus samples and from blood samples of their respective parents. A total of 30 pedigrees were analyzed. The results showed strict Mendelian inheritance. The cumulative paternity index (PI) and probability of paternity (W) obtained with D2S44, D17S79 and D4S163 loci were sufficient to exceed the required standard (PI > 369, W > 99.73) for assertion of paternity for all pedigrees tested. Therefore, these three loci are likely to satisfy the paternity test requirements in the majority of paternity cases, involving unrelated individuals, in the Chinese Han population. The other combinations of three loci did not produce high enough values for all cases, but all W values were > 98%. The results show that, using DNA from chorionic villi, these polymorphic loci can resolve cases of disputed paternity during early pregnancy.

Calculating paternity probabilities from DNA multilocus fingerprints in some cases of deficiency.

Paternity determination via DNA multilocus fingerprints in normal trio cases, namely when the fingerprints of the trio mother, child and putative father are available, is performed on a routine basis. But in cases of deficiency, where the DNA fingerprint of mother or putative father is missing, there exists no systematic, analytical way for paternity calculations, even in cases where DNA fingerprints of other persons related to the missing individual are available. The aim of this paper is to establish a mathematical, analytical background, that enables paternity calculations in cases of deficiency if complementary information can be obtained from the DNA fingerprints of at least one of the parents of the missing individual. Using the basic outline of our previously described procedure, the formulas for paternity calculations also allow mutations.

The Decision Theory of Paternity Disputes: Optimization Considerations Applied to Multilocus DNA Fingerprinting

The solution of paternity disputes using results from scientific analyses is studied from a decision-theoretical viewpoint. Two alternative approaches to decision making, the so-called 'Bayes' and 'Minimax' strategies, are described and discussed. If prior probabilities of paternity are exactly known, then Bayes decisions are (a) independent of the source of evidence and (b) optimal with respect to average losses caused by wrong decisions. However, it is concluded that Minimax decisions, which depend upon the employed test system but not upon prior probabilities, are more appropriate in paternity cases if equal prior good will towards disclaimed children and alleged fathers is demanded. It is further demonstrated that, when major evidence about paternity comes from multilocus DNA fingerprinting, prior probabilities must be known quite accurately for Bayes decisions to be superior with respect to average losses. Finally, we are able to show that 'quasi' Bayes decision making, that is, adopting a neutral prior probability of 0.5 but leaving thresholds for decision making unchanged, coincides with Minimax decision making if multilocus DNA fingerprinting is employed.

Sex Differences in Jealousy: Evolution, Physiology, and Psychology

In species with internal female fertilization, males risk both lowered paternity probability and investment in rival gametes if their mates have sexual contact with other males. Females of such species do not risk lowered maternity probability through partner infidelity, but they do risk the diversion of their mates' commitment and resources to rival females. Three studies tested the hypothesis that sex differences in jealousy emerged in humans as solutions to the respective adaptive problems faced by each sex. In Study 1, men and women selected which event would upset them more—a partner's sexual infidelity or emotional infidelity. Study 2 recorded physiological responses (heart rate, electrodermal response, corrugator supercilii contraction) while subjects imagined separately the two types of partner infidelity. Study 3 tested the effect of being in a committed sexual relationship on the activation of jealousy. All studies showed large sex differences, confirming hypothesized sex linkages in jealousy activation.

The function of menstrual taboos among the dogon

Menstrual taboos are nearly ubiquitous and assume parallel forms in geographically distant populations, yet their function has baffled researchers for decades. This paper proposes that menstrual taboos are anticuckoldry tactics. By signaling menstruation, they may advertise female reproductive status to husbands, affines, and other observers. Females may therefore have difficulty in obfuscating the timing of the onset of pregnancy. This may have three consequences: (a) males are better able to assess their probabilities of paternity and to direct their parental investment toward genetic offspring; (b) adulterous pregnancies are more easily detected and penalized, enhancing sexual fidelity; and (c) males avoid marrying pregnant females by relying on menstruation as evidence of nonpregnancy. This hypothesis is tested with 29 months of field data on menstrual taboos among the Dogon of Mali. Key results include the following: (a) cuckoldry is a major Dogon concern, (b) menstrual huts advertise female reproductive status, (c) husbands impose the taboos upon their wives, (d) female defiance of the taboos is undetectable and probably rare, and (e) informants think that the taboos help husbands and patrilineages to avoid cuckoldry. Thus the anti-cuckoldry hypothesis provides helpful insight into the menstrual taboos of the Dogon and should be tested among other populations.

Male investment under changing conditions among chacma baboons at Suikerbosrand.

Male investment in infant baboons was measured by frequency of carrying from 1978 through 1985. A series of hypotheses was generated and tested with the carrying data, based on the assumptions that: male baboons have some capacity to estimate likelihood of paternity; where paternity probability is greater, males will invest more, where potential benefits to males or infants are higher, males will invest more. Carrying was affected by probability of paternity, availability of estrous females, season of conception and season of carrying, infant age, subtrooping, and predation risk. Infants were carried by probable fathers, siblings, mothers' siblings, and unrelated "suitors." Male investment increased female reproductive fitness: carried infants were more likely to survive, and mothers of carried infants had shorter interbirth intervals. Males appeared to estimate paternity both by observed copulations by other males and by the likelihood that copulations could have occurred without being observed. Male care of infant baboons may also be affected by female choice among males, the distribution of probable infants in time, male tenure at alpha rank, the number of males per troop, the probability of infanticide, and energy demands. Subtrooping seems to be historically crucial, by initially creating a situation in which some males have high paternity certainty.

A genetic factor model for the statistical analysis of multilocus DNA fingerprints.

A novel concept is described for the statistical analysis of multilocus DNA fingerprints. Utilizing this method, it is shown by simulation that the application of multilocus DNA fingerprints to paternity testing is robust against deviations from idealistic assumptions made about underlying models and parameters. Partial homozygosity, allelism and linkage at the DNA loci involved, as well as variations in estimates of band-sharing probabilities were studied for effects on the resulting paternity probabilities. None of the above-mentioned phenomena appear to change these values to an extent relevant for decision making in paternity cases.

Validating the probability of paternity

In cases of disputed parentage, it is commonly thought that the probability of paternity (P) represents the probability that the tested man is the biologic father of the child whose parentage is in doubt and that the paternity index (PI) is the likelihood ratio that enters into this probability. Using the results of HLA typing in a sample of disputed parentage cases, the distribution of P was examined within two groups: actual mother-alleged father-child trios, and simulated mother-unrelated man-child trios. These distributions were found to be roughly consistent with the usual understanding of P.

A DNA Probe That Yields Highly Informative DNA Fingerprints for the Threespine Stickleback

Abstract To assess the utility of DNA probes for paternity and maternity analysis in threespine sticklebacks Gasterosteus aculeatus, we tested the bacteriophage genome M13 and the locus-specific VNTR (variable number of tandem repeats) probes pYNZ37.3, pYNZ22, pYNZ32, and pYNZl32, which are of human origin. Using DNA from threespine sticklebacks randomly collected, and hence presumably unrelated, we obtained informative DNA fingerprints (i.e., with clearly defined bands) only with M13 and pYNZl32. We examined the band-sharing indices (BSIs; i.e., fraction of bands shared by two individuals) obtained with these two probes. Digestion with Alu I, Hae III, or Msp I, yielded BSIs between 0.42 and 0.53 for M13 and between 0.18 and 0.23 for pYNZ132. Using pYNZ132, we analyzed the BSIs of 1 male and 10 randomly chosen fry of its brood. Based on the average BSI for unrelated individuals (i.e., the probability of sharing a band with an unrelated individual), we calculated the probabilities of incorrect paternity as...

DNA investigations on fetal material from paternity cases

Three paternity cases have been investigated where DNA was extracted from fetuses (age: 8-10 weeks old) after interruption of pregnancy. In each case it was possible to clearly identify the putative father using 5 or 6 single locus probes (SLP's). Fetal bands (SLP) could be clearly identified from mixtures of placental and fetal DNA by comparison with the maternal and paternal bands. However, it was very difficult to resolve the fragment patterns of tissue mixtures with one multi locus probe (MLP), because of band overlap. Another advantage of using SLP's was that biostatistical calculations could be carried out and very informative Essen-Möller values for the probability of paternity were obtained.

The examination of the ITI system in disputed paternities

106 paternity cases with a total of 114 putative fathers were examined in the inter-alpha-trypsin inhibitor (ITI) system. Analysis was performed by isoelectric focusing (IEF) of untreated sera on polyacrylamide gels. From 39 paternity exclusions, determined in other genetic systems, 7 were confirmed in the ITI system. In 75 expertises the alleged man was not excluded from fatherhood; in 68 cases the probability of paternity was W greater than 99.73%. The practical exclusion rate in the ITI system was therefore calculated to be 10.45%. The theoretical exclusion rate was determined to be 19.3%. In one paternity case the alleged father and the child showed inverse homozygosity in the ITI system, while the man was not excluded from fatherhood in 28 additional marker systems. The calculated probability of his paternity was 99.99%. The assumption of an incomplete expression of the ITI phenotypes in infants is supported by a significant deviation between the observed and expected ITI distributions at population equilibrium.

Sperm Competition in the Soybean Looper (Lepidoptera: Noctuidae)

Sperm use patterns in the soybean looper, Pseudoplusia includens (Walker), were examined with electrophoretic enzyme markers. Sixteen of 18 females mated more than once in a laboratory setting; of these, 5 mated four times, 3 mated three times, and 8 mated twice. Nine females met the experimental criteria for paternity analysis using a maximum likelihood method. Paternity probabilities indicated that, after a second mating, most females (five) primarily use the sperm from the first male for fertilization of their eggs. This pattern varied, however: two females showed a small amount of sperm mixing and two showed second male sperm precedence. Benefits to females of multiple mating do not appear to be related to sperm replenishment but may instead occur to provide additional nutrients from spermatophores or to compensate for infertile initial matings.