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1.
JOYCE C. HAVSTAD 《Bioethics》2010,24(2):71-77
Proponents of human reproductive cloning do not dispute that cloning may lead to violations of clones' right to self-determination, or that these violations could cause psychological harms. But they proceed with their endorsement of human reproductive cloning by dismissing these psychological harms, mainly in two ways. The first tactic is to point out that to commit the genetic fallacy is indeed a mistake; the second is to invoke Parfit's non-identity problem. The argument of this paper is that neither approach succeeds in removing our moral responsibility to consider and to prevent psychological harms to cloned individuals. In fact, the same commitment to personal liberty that generates the right to reproduce by means of cloning also creates the need to limit that right appropriately. Discussion of human reproductive cloning ought to involve a careful and balanced consideration of both the relevant aspects of personal liberty – the parents' right to reproductive freedom and the cloned child's right to self-determination. 相似文献
2.
Sayyed Mohammad Hossein Ghaderian Reza Akbarzadeh Fatemeh Mohajerani Zohreh Khodaii Saghar Salehpour 《Molecular reproduction and development》2019,86(8):964-971
Ovarian hyperstimulation syndrome (OHSS) is an undesirable complication in the course of ovarian stimulation. This kind of stimulation is aimed at acquiring a sufficient number of high‐quality oocytes in in vitro fertilization (IVF). Whereas the predisposition to OHSS could be impacted by genetic polymorphisms in susceptible genes, the present study has been jointly conducted with an Iranian cohort to scrutinize its relevant implication. Genomic DNA was extracted from blood samples of patients with a normal ovarian response (NOR) or with OHSS. Samples were analyzed to detect polymorphisms MTHFR rs1801131, MTHFR rs1801133, AMHR2 rs2002555, LHCGR rs2293275, PGR rs10895068, and SERPINE1 rs1799889. Variations of MTHFR, AMHR2, LHCGR, and PGR genes were significantly associated with the developing OHSS. After correction for multiple analysis, this difference was not evident for PGR genotypes. The polymorphic alleles of MTHFR (rs1801131 C‐allele and rs1801133 T‐allele), AMHR2 (rs2002555 G‐allele), and LHCGR (rs2293275 G‐allele) were significantly more prevalent among patients with OHSS compared to those in the NOR group. In contrast, the minor allele of PGR single‐nucleotide polymorphism (SNP) (rs10895068, A‐allele) was more prominent among patients with a NOR than those with OHSS. No significant difference was observed in genotypes or alleles of SERPINE1 rs1799889. The observations indicated that the minor alleles of MTHFR, AMHR2, and LHCGR genes could be considered an independent risk factor in susceptibility to OHSS. Nevertheless, polymorphic allele in the PGR rs10895068 SNP contributes to preventing OHSS occurrence. Therefore, it can be argued that these genes have a significant impact on OHSS. 相似文献
3.
Expanded universal carrier screening (EUCS) entails a population‐wide screening offer for multiple disease‐causing mutations simultaneously. Although there is much debate about the conditions under which EUCS can responsibly be introduced, there seems to be little discussion about its aim: providing carrier couples with options for autonomous reproductive choice. While this links in with current accounts of the aim of foetal anomaly screening, it is different from how the aim of ancestry‐based carrier screening has traditionally been understood: reducing the disease burden in the population. The reasons why the aim of EUCS is presented in terms of ‘autonomy’ rather than ‘prevention’ have not been spelled out in the literature. This paper seeks to fill this gap by considering the morally relevant similarities and dissimilarities between foetal anomaly screening, ancestry‐based carrier screening and EUCS. When carrier screening is performed in the prenatal period, enhancing autonomy appears the most appropriate aim of EUCS, as the alternative of ‘prevention through selective abortion’ would urge women to terminate wanted pregnancies. However, when screening is conducted in the preconception period, carrier couples can avoid the birth of affected children by other means than selective abortion, for instance preimplantation genetic diagnosis. To the extent that this increased control over passing on a genetic disorder raises questions of parental responsibility, it seems necessary that the account of the aims of EUCS is wider than only in terms of enhancing reproductive autonomy. 相似文献
4.
In vitro gametogenesis (IVG) is believed to be the next big breakthrough in reproductive medicine. The prima facie acceptance of this possible future technology is notable when compared to the general prohibition on human reproductive cloning. After all, if safety is the main reason for not allowing reproductive cloning, one might expect a similar conclusion for the reproductive application of IVG, since both technologies hold considerable and comparable risks. However, safety concerns may be overcome, and are presumably not the sole reason why cloning is being condemned. We therefore assess the non‐safety arguments against reproductive cloning, yet most of these can also be held against IVG. The few arguments that cannot be used against IVG are defective. We conclude from this that it will be hard to defend a ban on reproductive cloning while accepting the reproductive use of IVG. 相似文献
5.
Abstract In many organisms, large offspring have improved fitness over small offspring, and thus their size is under strong selection. However, due to a trade-off between offspring size and number, females producing larger offspring necessarily must produce fewer unless the total amount of reproductive effort is unlimited. Because differential gene expression among environments may affect genetic covariances among traits, it is important to consider environmental effects on the genetic relationships among traits. We compared the genetic relationships among egg size, lifetime fecundity, and female adult body mass (a trait linked to reproductive effort) in the seed beetle, Stator limbatus , between two environments (host-plant species Acacia greggii and Cercidium floridum ). Genetic correlations among these traits were estimated through half-sib analysis, followed with artificial selection on egg size to observe the correlated responses of lifetime fecundity and female body mass. We found that the magnitude of the genetic trade-off between egg size and lifetime fecundity differed between environments–a strong trade-off was estimated when females laid eggs on C. floridum seeds, yet this trade-off was weak when females laid eggs on A. greggii seeds. Also differing between environments was the genetic correlation between egg size and female body mass–these traits were positively genetically correlated for egg size on A. greggii seeds, yet uncorrelated on C. floridum seeds. On A. greggii seeds, the evolution of egg size and traits linked to reproductive effort (such as female body mass) are not independent from each other as commonly assumed in life-history theory. 相似文献
6.
7.
Soini Sirpa; Ibarreta Dolores; Anastasiadou Violetta; Ayme Segolene; Braga Suzanne; Cornel Martina; Coviello Domenico A.; Evers-Kiebooms Gerry; Geraedts Joep; Gianaroli Luca; Harper Joyce; Kosztolanyi Gyorgy; Lundin Kersti; Rodrigues-Cerezo Emilio; Sermon Karen; Sequeiros Jorge; Tranebjaerg Lisbeth; Kaariainen Helena 《ESHRE Monographs》2006,2006(1):2-51
19 To whom correspondence should be addressed at: Department of Medical Genetics, University of Turku, Kiinamyllykatu 10, FIN-20520 Turku, Finland. E-mail: hkaaria{at}utu.fi* Reprinted from European Journal of Human Genetics (2006) 1–58 with permission. The views expressed in this study do not necessarily reflect those of the European Commission (EC). The interface between assisted reproductive technologies (ART)and genetics comprises several sensitive and important issuesthat affect infertile couples, families with severe geneticdiseases, potential children, professionals in ART and genetics,health care, researchers and the society in general. Geneticcauses have a considerable involvement in infertility. Geneticconditions may also be transmitted to the offspring and hencecreate transgenerational infertility or other serious healthproblems. Several studies also suggest a slightly elevated riskof birth defects in children born following ART. PGD has becomewidely practiced throughout the world for various medical indications,but its limits are being debated. The attitudes towards ARTand PGD vary substantially within Europe. The purpose of thisarticle was to outline a framework for development of guidelinesto be issued jointly by European Society of Human Genetics (ESHG)and European Society of Human Reproduction and Embryology (ESHRE)for the interface between genetics and ART. Technical, social,ethical and legal issues of ART and genetics will be reviewed. 相似文献
8.
Bennett R 《Bioethics》2009,23(5):265-273
The claim that we have a moral obligation, where a choice can be made, to bring to birth the 'best' child possible, has been highly controversial for a number of decades. More recently Savulescu has labelled this claim the Principle of Procreative Beneficence. It has been argued that this Principle is problematic in both its reasoning and its implications, most notably in that it places lower moral value on the disabled. Relentless criticism of this proposed moral obligation, however, has been unable, thus far, to discredit this Principle convincingly and as a result its influence shows no sign of abating. I will argue that while criticisms of the implications and detail of the reasoning behind it are well founded, they are unlikely to produce an argument that will ultimately discredit the obligation that the Principle of Procreative Beneficence represents. I believe that what is needed finally and convincingly to reveal the fallacy of this Principle is a critique of its ultimate theoretical foundation, the notion of impersonal harm. In this paper I argue that while the notion of impersonal harm is intuitively very appealing, its plausibility is based entirely on this intuitive appeal and not on sound moral reasoning. I show that there is another plausible explanation for our intuitive response and I believe that this, in conjunction with the other theoretical criticisms that I and others have levelled at this Principle, shows that the Principle of Procreative Beneficence should be rejected. 相似文献
9.
Peter H. Niewiarowski Arthur E. Dunham 《Evolution; international journal of organic evolution》1994,48(1):137-145
We evaluated Shine and Schwarzkopf's (SS) model of the evolution of reproductive effort (RE) in squamate reptiles. They suggested that fecundity trade-offs were unimportant in the evolution of RE in most squamate reptiles and that only survival trade-offs needed to be considered. However, we show that by assuming no variation in offspring size exists, and that adult mortality is episodic, the results of the SS model are not general. By extension, we argue that conclusions drawn about factors important in the evolution of RE in squamate reptiles are premature. Using a modified version of the SS model, we demonstrate that variation in the form of trade-offs relating offspring size and survival substantially affect relationships among clutch size, relative clutch mass, and lifetime reproductive success. We also demonstrate that the way in which adult mortality is simulated drastically affects conclusions about the potential fecundity trade-offs experienced by populations of squamate reptiles. Finally, we suggest that a complete understanding of the evolution of RE will come from theory that incorporates trade-offs between offspring size and quality, as well as other system-specific constraints on the allocation of energy to growth, maintenance, storage, and reproduction. 相似文献
10.
Crosses between populations or species often display an asymmetry in the fitness of reciprocal F1 hybrids. This pattern, referred to as isolation asymmetry or Darwin''s Corollary to Haldane''s Rule, has been observed in taxa from plants to vertebrates, yet we still know little about which factors determine its magnitude and direction. Here, we show that differences in offspring size predict the direction of isolation asymmetry observed in crosses between populations of a placental fish, Heterandria formosa. In crosses between populations with differences in offspring size, high rates of hybrid inviability occur only when the mother is from a population characterized by small offspring. Crosses between populations that display similarly sized offspring, whether large or small, do not result in high levels of hybrid inviability in either direction. We suggest this asymmetric pattern of reproductive isolation is due to a disruption of parent–offspring coadaptation that emerges from selection for differently sized offspring in different populations. 相似文献
11.
According to what we call the Principle of Procreative Beneficence (PB), couples who decide to have a child have a significant moral reason to select the child who, given his or her genetic endowment, can be expected to enjoy the most well-being. In the first part of this paper, we introduce PB, explain its content, grounds, and implications, and defend it against various objections. In the second part, we argue that PB is superior to competing principles of procreative selection such as that of procreative autonomy. In the third part of the paper, we consider the relation between PB and disability. We develop a revisionary account of disability, in which disability is a species of instrumental badness that is context- and person-relative. Although PB instructs us to aim to reduce disability in future children whenever possible, it does not privilege the normal. What matters is not whether future children meet certain biological or statistical norms, but what level of well-being they can be expected to have. 相似文献
12.
1. Viviparous insects such as tsetse ( Glossina spp.) provide unusual opportunities to compare age-related changes in the proportion of maternal resources transferred to offspring.
2. In laboratory populations of Glossina morsitans morsitans the survival of females was high for the first 60 days of adult life but declined rapidly thereafter.
3. Average longevity did not differ significantly between mated and unmated females (93·6 and 90 days, respectively).
4. Nutritional state in terms of fat content and residual dry mass did not decline with adult female age.
5. The fecundity of mated females was constant for the first 60 days of adult life and declined only slightly thereafter.
6. Offspring size did not change towards the end of the adult female lifespan and there was no evidence of an increase in the allocation of resources to reproduction in older females.
7. Results contrast with those obtained recently for vertebrates and may indicate that age-related changes in offspring size in Glossina are not adaptive, or that so few females reach old age under natural conditions that there is no selection for a strategy of terminal investment. 相似文献
2. In laboratory populations of Glossina morsitans morsitans the survival of females was high for the first 60 days of adult life but declined rapidly thereafter.
3. Average longevity did not differ significantly between mated and unmated females (93·6 and 90 days, respectively).
4. Nutritional state in terms of fat content and residual dry mass did not decline with adult female age.
5. The fecundity of mated females was constant for the first 60 days of adult life and declined only slightly thereafter.
6. Offspring size did not change towards the end of the adult female lifespan and there was no evidence of an increase in the allocation of resources to reproduction in older females.
7. Results contrast with those obtained recently for vertebrates and may indicate that age-related changes in offspring size in Glossina are not adaptive, or that so few females reach old age under natural conditions that there is no selection for a strategy of terminal investment. 相似文献
13.
近年来研究显示,kisspeptin在大脑的性别分化、性激素正负反馈调节、青春期始动以及机体能量信号转导等生理过程中起到重要作用,表明kisspeptin可能是女性生殖功能成熟及调控的一个关键性信号因子。除下丘脑分泌的kisspeptin之外,生殖器官局部表达的kisspeptin在机体正常生殖过程中的作用也不断得到证实。研究表明,很多生殖内分泌疾病,如单纯性促性腺激素分泌不足的性腺机能减退症(isolated hypogonadotropic hypogonadism, IHH)、多囊卵巢综合征(polycystic ovary syndrome, PCOS)、卵巢早衰(premature ovarian failure, POF)、病理性高泌乳素血症等,都与kisspeptin的异常表达有关。通过给予外源性kisspeptin可解决辅助生殖技术应用中的一些问题。本文主要就kisspeptin在女性生殖内分泌尤其是在辅助生殖领域研究中所取得的进展进行论述。 相似文献
14.
Reproductive events in animal societies often show a high degree of temporal clustering, but the evolutionary causes of this synchronization are poorly understood. Here, we suggest that selection to avoid the negative effects of competition with other females has given rise to a remarkable degree of birth synchrony in the communal-breeding banded mongoose (Mungos mungo). Within banded mongoose groups, births are highly synchronous, with 64 per cent of females giving birth on exactly the same night. Our results indicate that this extreme synchrony arises because offspring suffer an increased risk of infanticide if their mother gives birth before other females, but suffer in competition with older littermates if their mother gives birth after them. These findings highlight the important influence that reproductive competition can have for the evolution of reproductive synchrony. 相似文献
15.
目的研究雌性小鼠饲喂异黄酮后对其后代雌鼠生殖性状的影响。方法分别在雌鼠从断奶到妊娠前和妊娠期间两个不同阶段的日粮中添加不同剂量的大豆异黄酮（0、50、400 mg/kg）。记录F1代的出生窝产仔数、出生窝重、雌鼠的阴道最早开张时间和最早见栓时间,以及后代雌鼠性成熟期和体成熟期生殖器官重量、血清雌激素的含量。结果雌鼠妊娠期饲喂含50、400 mg/kg大豆异黄酮的饲料后F1代的窝产仔数显著高于对照组（P〈0.05）;雌鼠妊娠期采食400 mg/kg大豆异黄酮饲料,其后代雌鼠初次配种时间明显延迟（P〈0.05）;45、65日龄体重显著低于对照组,65日龄子宫重显著低于对照组,卵巢重显著高于对照组;血清中雌激素含量显著低于对照组（P〈0.05）,妊娠期间采食50 mg/kg大豆异黄酮饲料,其F1代雌鼠仅窝产仔数和45日龄时血清中雌激素含量受到影响;而雌鼠从断奶到怀孕期间饲喂含大豆异黄酮饲料的F1代在各项指标与对照组均差异无显著性。结论雌鼠妊娠期间饲喂含400 mg/kg大豆异黄酮的饲料会显著影响其雌性后代的初情期、生殖器官发育、血清雌激素含量等生殖生理性状,而在非妊娠期饲喂含大豆异黄酮饲料对F1代无显著影响。 相似文献
16.
Lane R 《Bioethics》2006,20(3):125-135
Some opponents of reproductive human cloning have argued that, because of its experimental nature, any attempt to create a child by way of cloning would risk serious birth defects or genetic abnormalities and would therefore be immoral. Some versions of this argument appeal to the consent of the person to be conceived in this way. In particular, they assume that if an experimental reproductive technology has not yet been shown to be safe, then, before we use it, we are morally obligated to get either the actual consent or the presumed consent of the person to be conceived. In this article, I attempt to explain the appeal of such consent-based arguments as deriving from a mistaken view of personal identity. I then argue that since this view is false, such arguments are unsound. Finally, I argue that even if reproductive cloning is unsafe, it may still be morally permissible in some circumstances. 相似文献
17.
为了明确班氏跳小蜂不同生殖方式及雌蜂密度对种群的影响,研究了班氏跳小蜂在不同雌雄比例的两性生殖和孤雌生殖条件下以及不同雌蜂密度情况时,其寄生率及子代的雌性比例。结果表明:班氏跳小蜂可进行两性生殖和产雄孤雌生殖,不同雌雄比例的两性生殖及孤雌生殖的寄生率随着雌蜂数量的增加不断升高,雌雄比为20∶1时的寄生率最高,为49.13%;在两性生殖雌雄比为15∶1的情况下,其后代雌性最高;不同粉蚧密度条件下,2头雌蜂同时存在时,其寄生率和子代性比均最高。说明两性生殖(雌雄比为15∶1)和2头雌蜂同时存在条件下,更利于班氏跳小蜂种群发展。 相似文献
18.
Hassen Allegue;Christophe Guinet;Samantha C. Patrick;Cécile Ribout;Coraline Bichet;Olivier Lepais;Denis Réale; 《Marine Mammal Science》2024,40(3):e13108
In polygynous species, male reproductive success is often determined by their ability to dominate female harems. Harem-holders sire a disproportionate number of offspring. Male dominance tends to correlate with age, but intense competition and early male mortality limit most males from achieving high social status. To maximize reproductive success despite low rank, offspring sex ratio adjustment may have evolved, favoring the sex with higher fitness. If traits influencing dominance are heritable and confer reproductive advantages, we expect fathers with higher reproductive success to produce more sons, as they are more likely to become dominant. In contrast, subordinate males with lower success may benefit from siring more daughters. We tested this hypothesis on a colony of southern elephant seals breeding on the Kerguelen Archipelago. We used genetic markers to link the paternity of 540 pups to 58 breeding males. We found that the probability of siring a son increases from 43% to 54% with paternal relative reproductive success, supporting the offspring sex ratio adjustment hypothesis. Given that various factors influence sex ratio in a population, future studies should tease apart these ecological processes (e.g., paternal dominance, maternal condition, local density, or adult sex ratio) and investigate how they interact with each other. 相似文献
19.
MIGUEL BARBOSA ANNE E. MAGURRAN 《Biological journal of the Linnean Society. Linnean Society of London》2010,100(2):414-419
Females that invest adaptively in their offspring are predicted to channel more resources to the sex that will be at an advantage in the prevailing environmental conditions. Here, we report, for the first time, that female Trinidadian guppy, Poecilia reticulata, respond in reproductively distinct ways when faced with differences in operational sex ratio. We show that females assigned to a female‐biased sex ratio produce larger male offspring than females in an environment in which males predominate. Given the link between size at birth and fitness, and the marked reproductive skew in this species, larger male offspring are expected to have reproductive advantages in guppy populations with an excess of females. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 414–419. 相似文献
20.
In the Parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), variation in body size exists between and within the sexes. The females are larger than the males. Darwin (1874) proposed the fecundity advantage hypothesis, that is, large‐sized females produce more progeny, with subsequent studies supporting, as well as, refuting the hypothesis. Thus, in order to evaluate whether this hypothesis stands in Z. bicolorata we performed experiments to investigate the role of body size in influencing: (i) assortative mating; (ii) reproductive attributes; and (iii) growth, development and survival of offspring. It is the first attempt in this beetle. We found that size influenced assortative mating, reproductive output and offspring fitness. Larger males and females were preferred as mates over smaller ones. The pairs, having larger adults as mates, had higher fecundity, while the egg viability was influenced by the male size only. The offspring of larger parents had fast development and higher survival, indicating thereby possible better nutrient allotment by the female and supply of accessory gland proteins by the male in addition to better quality of genes. 相似文献