Article
To read the full-text of this research, you can request a copy directly from the author.

Abstract

Biological studies have demonstrated that it is possible to slow the ageing process and extend lifespan in a wide variety of organisms, perhaps including humans. Making use of the findings of these studies, this article examines two problems concerning the effect of life extension on population size and welfare. The first-the problem of overpopulation-is that as a result of life extension too many people will co-exist at the same time, resulting in decreases in average welfare. The second-the problem of underpopulation-is that life extension will result in too few people existing across time, resulting in decreases in total welfare. I argue that overpopulation is highly unlikely to result from technologies that slow ageing. Moreover, I claim that the problem of underpopulation relies on claims about life extension that are false in the case of life extension by slowed ageing. The upshot of these arguments is that the population problems discussed provide scant reason to oppose life extension by slowed ageing.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... These consequences can be roughly divided into implications for society generally, for present individuals, and for future individuals (Singer 1991). Perhaps most obviously concerning are the social problems, particularly the increased population strain on an overtaxed planet (Wareham 2015), the inevitable increase in the number of super-aged societies (Fukuyama 2002), and the increased burden of expensive chronic diseases in the developed and developing world (Callahan and Gaylin 2017). Alongside these broad social concerns, there are also concerns at the level of individual well-being: even if healthy lifespans could be extended, how would the human mind cope with extended life (Wareham 2012;Murphy 2015)? ...
... Perhaps most obviously concerning are the social problems, particularly the increased population strain on an overtaxed planet (Wareham 2015), the inevitable increase in the number of super-aged societies (Fukuyama 2002), and the increased burden of expensive chronic diseases in the developed and developing world (Callahan and Gaylin 2017). Alongside these broad social concerns, there are also concerns at the level of individual well-being: even if healthy lifespans could be extended, how would the human mind cope with extended life (Wareham 2012;Murphy 2015)? Would boredom inevitably ensue (Harris 2000)? ...
... A further problem with the Objection from Loneliness concerns the idea that longer lives will be bad or harmful. The notion of harm can be understood in at least two ways: first, as a condition that is bad in and of itself, and second as resulting in comparatively worse situation, so that our lives would go better if the harm were not there (Wareham 2009). For instance, we might say that a vaccination is harmful in the first sense, since it involves some pain and discomfort. ...
Article
The development of gene-editing technologies, such as the clustered regularly interspaced short palindromic repeats and associated Cas9 endonuclease (CRISPR/Cas9) system, coincides with a rapidly expanding knowledge of the role of genes in the human ageing process. This raises the prospect that, in addition to the treatment of genetic diseases and disorders, it may become possible to use gene-editing technologies to alter the ageing process and significantly extend the maximum human lifespan. Germline editing poses distinctive problems due to its implications for individual members of future, unborn generations. In this essay, I wish to home in, narrowly, on a single ethical objection to extending the lifespan of future generations by editing the human germline. The objection suggests that to extend lifespans is to unethically inflict the harm of loneliness on future people. I claim that the argument rests on assumptions that ought to be rejected.
... Seremos más precisos y eficaces a la hora de prescribir fármacos. Sin embargo abrirá un profundo debate relativo a la "gran longevidad" (personas centenarias) y la sostenibilidad del Estado del Bienestar (5). Otro efecto indeseable será detectar predisposiciones a enfermedades para las cuales no tenemos ni ahora, ni quizás en un futuro próximo, prevención ni tratamiento… Advirtamos enseguida que ambos modelos pueden ser vividos bajo el mismo prisma de control que criticábamos para el modelo de "vida natural". ...
Article
Full-text available
n our eagerness to control our health we can embrace metaphysical models that explain the vicissitudes of our lives and prescribe preventive behaviors. The model we call "of natural life" proposes that a strict life regime is capable of preventing chronic diseases and even reversing its course. It is a very widespread model and sometimes justifies the lack of adherence to chronic medications. The psychological benefit of this model is to make the future predictable. When these people face serious illnesses they are usually disappointed with this model, and sometimes they claim a hyper-technified and highly intrusive model as a guarantor of their health. - See more at: http://revista.fundacionletamendi.com/index.php/ficha/101/La-hiptesis-de-una-vida-natural#sthash.a2JJsqOo.dpuf
Article
Many researchers are working toward the goal of finding a treatment that halts or even reverses the aging process of the human body, a treatment that would make the recipient potentially immortal. The hope that they will succeed in the relatively near future is gaining ground among academics and laypeople alike. What will happen if this hope becomes reality? Specifically, how will our political and social institutions and practices be affected by that discovery? These are the questions raised in the present paper. Concretely, I will discuss three political and social problems that the invention of an immortality treatment is likely to provoke, namely the struggle for access to that treatment, the threat of overpopulation, and the friction between potentially immortal individuals.
Article
Applied ethics is home to numerous productive subfields such as procreative ethics, intergenerational ethics and environmental ethics. By contrast, there is far less ethical work on ageing, and there is no boundary work that attempts to set the scope for ‘ageing ethics’ or the ‘ethics of ageing’. Yet ageing is a fundamental aspect of life; arguably even more fundamental and ubiquitous than procreation. To remedy this situation, I examine conceptions of what the ethics of ageing might mean and argue that these conceptions fail to capture the requirements of the desired subfield. The key reasons for this are, first, that they view ageing as something that happens only when one is old, thereby ignoring the fact that ageing is a process to which we are all subject, and second that the ageing person is treated as an object in ethical discourse rather than as its subject. In response to these shortcomings I put forward a better conception, one which places the ageing person at the centre of ethical analysis, has relevance not just for the elderly and provides a rich yet workable scope. While clarifying and justifying the conceptual boundaries of the subfield, the proposed scope pleasingly broadens the ethics of ageing beyond common negative associations with ageing.
Chapter
Transhumanists advocate humankind’s transcendence of biological barriers to well-being. To achieve this they propose extensive development and use of enhancement technologies to improve the flawed human condition. A central goal of transhumanism, which I will refer to as the ‘transhumanist prospect’, is radical enhancement of human lifespans and control over the aging process. In this primarily descriptive contribution, I outline the transhumanist prospect and discuss philosophical and ethical debates about the transhumanist stance on aging. In doing so, I point to controversial premises in transhumanist thinking and provide what I regard as useful distinctions. In particular, I distinguish between different understandings of transhumanism and suggest being in favour of enhancement is not equivalent to being a transhumanist. Thereafter, I characterise three transhumanist ends that converge with respect to aging: freedom and self-control, making individuals better than well, and surmounting the limitations of human nature. Transhumanists advocate intervening in or escaping the aging process, and I differentiate between five modes whereby this may be achieved. Finally, I examine several types of ethical objections related to the transhumanist prospect.
Article
One of the strongest objections to the development and use of substantially life-extending interventions is that they would exacerbate existing unjust disparities of healthy lifespans between rich and poor members of society. In both popular opinion and ethical theory, this consequence is sometimes thought to justify a ban on life-prolonging technologies. However, the practical and ethical drawbacks of banning receive little attention, and the viability of alternative policies is seldom considered. Moreover, where ethicists do propose alternatives, there is scant effort to consider their merits in light of developing world priorities. In response to these shortcomings, I distinguish four policy options and, on the basis of a plausible intuition about fairness, evaluate their implications for a fair distribution of healthy lifespans. I claim that even in developing nations it would be fairest to favor policies that promote equal access to at least one promising category of substantially life-extending intervention: calorie restriction mimetics.
Article
Full-text available
Recent developments in biogerontology-the study of the biology of ageing-suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan-a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the 'double effect argument', has gone unnoticed. This article exposes and critically evaluates this 'double effect argument'. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the 'double effect argument' is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning.
Article
Full-text available
Resveratrol (3,5,4'-trihydroxystilbene) extends the lifespan of diverse species including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster. In these organisms, lifespan extension is dependent on Sir2, a conserved deacetylase proposed to underlie the beneficial effects of caloric restriction. Here we show that resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival. Resveratrol produces changes associated with longer lifespan, including increased insulin sensitivity, reduced insulin-like growth factor-1 (IGF-I) levels, increased AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor- coactivator 1 (PGC-1) activity, increased mitochondrial number, and improved motor function. Parametric analysis of gene set enrichment revealed that resveratrol opposed the effects of the high-calorie diet in 144 out of 153 significantly altered pathways. These data show that improving general health in mammals using small molecules is an attainable goal, and point to new approaches for treating obesity-related disorders and diseases of ageing.
Article
Full-text available
Rapamycin was administered in food to genetically heterogeneous mice from the age of 9 months and produced significant increases in life span, including maximum life span, at each of three test sites. Median survival was extended by an average of 10% in males and 18% in females. Rapamycin attenuated age-associated decline in spontaneous activity in males but not in females. Causes of death were similar in control and rapamycin-treated mice. Resveratrol (at 300 and 1200 ppm food) and simvastatin (12 and 120 ppm) did not have significant effects on survival in male or female mice. Further evaluation of rapamycin’s effects on mice is likely to help delineate the role of the mammalian target of rapamycin complexes in the regulation of aging rate and age-dependent diseases and may help to guide a search for drugs that retard some or all of the diseases of aging.
Article
Full-text available
Since the 1930s scientists from fields such as biochemistry, pathology, immunology, genetics, neuroscience, and nutrition have studied the relation of dietary caloric intake to longevity and aging. This paper discusses how Clive Maine McCay, a professor of animal husbandry at Cornell University, began his investigation of the topic and promoted it as a productive research program in the multidisciplinary science of gerontology. Initially, McCay observed the effect of reduced-calorie diets on life span and senescence while pursuing his nutrition research in the context of animal husbandry and agriculture. But when he received funding from the Rockefeller Foundation and started to participate in the establishment of gerontology during the 1930s, the scope of his research was considerably expanded beyond his original disciplinary domain. It became a multidisciplinary research program that attracted scholars from a variety of scientific and medical disciplines. This paper argues that through this expansion McCay's research created a means of maintaining cooperation among the diverse and heterogeneous academic fields constituting gerontology.
Article
Full-text available
Article
Full-text available
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species.
Article
Full-text available
This paper argues that the Quality Adjusted Life Year or QALY is fatally flawed as a way of priority setting in health care and of dealing with the problem of scarce resources. In addition to showing why this is so the paper sets out a view of the moral constraints that govern the allocation of health resources and suggests reasons for a new attitude to the health budget.
Article
Full-text available
When scientific advances lead to extended life spans, how will society plan population policies? Whether prolonging life is desirable or not, it is likely that expensive technologies will make life extension possible with far-reaching ethical and social consequences. Treating or preventing a whole range of diseases might have "immortality" as a side effect. Time-honored ethical principles will require radical rethinking before technological changes that prolong life outpace our vision of the future.
Article
Full-text available
Caloric restriction (CR) is the only experimental nongenetic paradigm known to increase lifespan. It has broad applicability and extends the life of most species through a retardation of aging. There is considerable interest in the use of CR in humans, and animal studies can potentially tell us about the impacts. In this article we highlight some of the things that animal studies can tell us about CR in humans. Rodent studies indicate that the benefits of CR on lifespan extension are related to the extent of restriction. The benefits of CR, however, decline as the age of onset of treatment is delayed. Modeling these impacts suggests that if a 48-y-old man engaged in 30% CR until his normal life expectancy of 78, he might increase his life expectancy by 2.8 y. Exercise and cold exposure induce similar energy deficits, but animals respond to these energy deficits in different ways that have a minor impact on lifespan. Measurements of animal responses when they cease restriction indicate that prolonged CR does not diminish hunger, even though the animals may have been in long-term energy balance. Neuroendocrine profiles support the idea that animals under CR are continuously hungry. The feasibility of restricting intake in humans for many decades without long-term support is questionable. However, what is unclear from animal studies is whether taking drugs that suppress appetite will generate the same impact on longevity or whether the neuroendocrine correlates of hunger play an integral role in mediating CRs effects.
Article
Full-text available
The wish to extend the human lifespan has a long tradition in many cultures. Optimistic views of the possibility of achieving this goal through the latest developments in medicine feature increasingly in serious scientific and philosophical discussion. The authors of this paper argue that research with the explicit aim of extending the human lifespan is both undesirable and morally unacceptable. They present three serious objections, relating to justice, the community and the meaning of life.
Article
Full-text available
Long-term caloric restriction (CR) is a robust means of reducing age-related diseases and extending life span in multiple species, but the effects in humans are unknown. The low caloric intake, long life expectancy, and the high prevalence of centenarians in Okinawa have been used as an argument to support the CR hypothesis in humans. However, no long-term, epidemiologic analysis has been conducted on traditional dietary patterns, energy balance, and potential CR phenotypes for the specific cohort of Okinawans who are purported to have had a calorically restricted diet. Nor has this cohort's subsequent mortality experience been rigorously studied. Therefore, we investigated six decades of archived population data on the elderly cohort of Okinawans (aged 65-plus) for evidence of CR. Analyses included traditional diet composition, energy intake, energy expenditure, anthropometry, plasma DHEA, mortality from age-related diseases, and current survival patterns. Findings include low caloric intake and negative energy balance at younger ages, little weight gain with age, life-long low BMI, relatively high plasma DHEA levels at older ages, low risk for mortality from age-related diseases, and survival patterns consistent with extended mean and maximum life span. This study lends epidemiologic support for phenotypic benefits of CR in humans and is consistent with the well-known literature on animals with regard to CR phenotypes and healthy aging.
Article
Full-text available
The aging of humanity is about to experience a radical change as the demographic transformation to an older world is approaching its final stage. In recent decades, scientists have learned enough about the biological aging processes that many believe it will become possible to slow aging in humans. We contend that the social, economic, and health benefits that would result from such advances may be thought of as "longevity dividends," and that they should be aggressively pursued as the new approach to health promotion and disease prevention in the 21st century. The time has arrived for governments and national and international healthcare organizations to make research into healthy aging a major research priority.
Article
There is considerable controversy over the causes of the completed fertility transitions that occurred in most industrial countries from 1870 to 1930 and the “new” fertility transitions that are currently underway in the developing world. New data and empirical analyses of both historical and contemporary fertility declines have weakened the standard theory of the demographic transition, but none of the plethora of new theories of fertility change have emerged as hegemonie or as alternative guides to empirical research. The vast body of empirical evidence on the origins, speed, and correlates of fertility declines in different historical and geographical settings shows more diversity than a simple theory of fertility change would predict. The challenge for the field is to develop a common theoretical framework that will accommodate the diversity of historical paths from high to low fertility.
Article
This article argues that whereas gender issues have become central in the population policy arena, they remain marginal to the demographic held, and that this marginality has harmful consequences for the development of demography as a science. This predicament has arisen because of ideological, not scientific, constraints on the field of demography-constraints that have a history in how the discipline was formed and financed and in how key demographic agendas become rationalized. The rise of modern feminism, with its commitment. to greater gender equality and female empowerment, presents a challenge in this context; it has limited appeal to those who control key resources for demographic research. The article argues for the incorporation of a gender systems approach that directly addresses gender differences in power, autonomy, and well-being, at both the macro and micro levels, and for an expansion of data collection that will permit such analyses. By making gender central to the field, demography will become a more relevant science for understanding social inequality and population change.
Article
Objections to life extension often focus on its effects for individual well-being. Prominent amongst these concerns is the possibility that life extending technologies will extend lifespan without preventing the ageing of the mind. Writers on the subject express the fear that life extending drugs will keep us physically youthful whilst our minds decay, succumbing to dementia, boredom, and loneliness. Generally these fears remain speculative, in part due to the absence of genuine life extending technologies. In this paper, however, I examine the implications of an existing life extension technology. Caloric restriction (CR) and drugs that mimic its effects, such as rapamycin, metformin and resveratrol have been shown to increase average and maximum lifespan in a wide variety of organisms, and seem likely to do so in humans. Moreover, some CR mimetic drugs (CRMs) are already widely used. This means that they present a pressing test case for fears about mental ageing in an extended life. Misgivings about mental ageing can be divided into biomedical factors such as the likelihood of brain ageing, and psychological factors such as loss of meaning and boredom. I argue that studies of CR suggest that brain ageing will be beneficially slowed. However, it is less clear that deleterious aspects of psychological ageing can be similarly retarded. I argue that this reduces the desirability of life extension unless major social changes can be made.
Article
Preface 1. Personal identity and individuation 2. Personal identity and bodily continuity 3. Imagination and the self 4. The self and the future 5. Are persons bodies? 6. The Makropulos case: reflections on the tedium of immortality 7. Strawson on individuals 8. Knowledge and meaning in the philosophy of mind 9. Deciding to believe 10. Imperative inference 11. Ethical consistency 12. Consistency and realism 13. Morality and the emotions 14. The idea of equality 15. Egoism and altruism Bibliography.
Article
abstract Some day, perhaps soon, we may have genetic enhancements enabling us to conquer aging. Should we do so, if we can? I believe the topic is both interesting and important, and that it behoves us to think about it. Doing so may yield important insights about what we do care about, what we should care about, and how we should seek to live our lives, both individually and collectively. My central question is this: Is living longer, living better? My paper does not offer a sustained argument for a single, considered, thesis. Rather, it offers a number of snippets of often-unconnected thoughts relevant to the issues my question raises. The paper contains seven sections. Part one is introductory. Part two comments on some current longevity research. Part three indicates the attitudes towards death and science with which I approach these questions. Parts four and five, respectively, discuss some worries about immortality raised by Leon Kass and Bernard Williams. Part six points to some practical, social, and moral concerns that might arise if society's members lived super long lives. Part seven concludes by suggesting that we should favour living well over living longer, and ongoing reproduction over immortality; correspondingly, I suggest that we should think long and hard before proceeding with certain lines of longevity research.
Article
abstract It seems to be a widespread opinion that increasing the length of existing happy lives is better than creating new happy lives although the total welfare is the same in both cases, and that it may be better even when the total welfare is lower in the outcome with extended lives. I shall discuss two interesting suggestions that seem to support this idea, or so it has been argued. Firstly, the idea there is a positive level of well-being above which a life has to reach to have positive contributive value to a population, so-called Critical Level Utilitarianism. Secondly, the view that it makes an outcome worse if people are worse off than they otherwise could have been, a view I call Comparativism. I shall show that although these theories do capture some of our intuitions about the value of longevity, they contradict others, and they have a number of counterintuitive implications in other cases that we ultimately have to reject them.
Article
New interventions into the aging process have already prolonged the life span of nematodes, fruit flies, mice, and most recently even of primates. What has been successful in laboratory animals may be applied to human aging in the long run as well. At the same time, the almost universal trend of population aging raises concerns that health care costs will rise significantly and that this trend will threaten universal and equal access to health-related services. Therefore, it is crucial to assess the potential impact of new age-related biomedical interventions on health care systems in order to predict who will have access to these interventions and how this will affect existing health inequities in old age. This would at first require data on the cost-effectiveness of new age-related interventions. However, such data are not yet available. Nevertheless, a discussion on the potential impact of this technological development in such an early stage has one big advantage: possible undesirable outcomes may still be prevented by timely regulatory action. Therefore, instead of trying to answer the question of the possible consequences for publicly and privately financed health care based on data concerning cost-effectiveness, we will try to anticipate which groups will presumably have access to these interventions into the aging process. We will also suggest a social justice framework to evaluate unequal access, based on a conception of health-related equality of opportunity. As a starting point for this projection, we will compare different biodemographic scenarios. According to our analysis, access to age-related interventions will be limited to certain population groups and this will further increase already existing health inequities among the elderly, which should be avoided from a social justice perspective. We suggest that the most promising strategy to prevent such a development would be to set priorities in publicly funded age-related research. An analysis of the development of NIA-funding and the current NIA strategy will examine to which extent starting points for such an ethically justified priority setting already exist and how it could basically be conceived.
Article
In the past decade, the small polyphenol resveratrol has received widespread attention as either a potential therapy or as a preventive agent for numerous diseases. Studies using purified enzymes, cultured cells, and laboratory animals have suggested that resveratrol has anti-aging, anti-carcinogenic, anti-inflammatory, and anti-oxidant properties that might be relevant to chronic diseases and/or longevity in humans. Although the supporting research in laboratory models is quite substantial, only recently data has emerged to describe the effects of resveratrol supplementation on physiological responses in humans. The limited number of human clinical trials that are available has largely described various aspects of resveratrol's safety and bioavailability, reaching a consensus that it is generally well-tolerated, but have poor bioavailability. Very few published human studies have explored the ability of resveratrol to achieve the physiological benefits that have been observed in laboratory models, although many clinical trials have recently been initiated. This review aims to examine the current state of knowledge on the effects of resveratrol on humans and to utilize this information to develop further guidelines for the implementation of human clinical trials.
Article
The potential for development of biomedical technologies capable of extending the human lifespan raises at least two kinds of question that it is important both to distinguish and to connect with one another: scientific, factual questions regarding the feasibility of life extension interventions; and questions concerning the ethical issues related to the extension of life- and healthspans. This paper provides an account of some life extension interventions considered to be amongst the most promising, and presents the ethical questions raised by the prospect of their pursuit. It is suggested that problems concerning the effects of these technologies on health care resources and on intergenerational relationships will be the most difficult to tackle.
Article
DemographyChina's one-child policy may have slowed population growth in the world's most populous country. But it has also produced a rapidly aging population, a shrinking labor force, and a skewed sex ratio at birth, perils that many demographers say could threaten China's economy and social fabric. As the most spectacular demographic experiment in history, the one-child policy is unprecedented in its scope and extremity. The measure is so sacrosanct that officials who have dared in the past to hint at its dissolution have been quickly silenced. But a growing number of experts contend that the policy, which turns 30 next week, has run its course.
Article
Some of the objections to life-extension stem from a concern with overpopulation. I will show that whether or not the overpopulation threat is realistic, arguments from overpopulation cannot ethically demand halting the quest for, nor access to, life-extension. The reason for this is that we have a right to life, which entitles us not to have meaningful life denied to us against our will and which does not allow discrimination solely on the grounds of age. If the threat of overpopulation creates a rights conflict between the right to come into existence, the right to reproduce, the right to more opportunities and space (if, indeed, these rights can be successfully defended), and the right to life, the latter ought to be given precedence.
Article
The disposable soma theory on the evolution of ageing states that longevity requires investments in somatic maintenance that reduce the resources available for reproduction. Experiments in Drosophila melanogaster indicate that trade-offs of this kind exist in non-human species. We have determined the interrelationship between longevity and reproductive success in Homo sapiens using a historical data set from the British aristocracy. The number of progeny was small when women died at an early age, increased with the age of death, reaching a plateau through the sixth, seventh and eighth decades of life, but decreased again in women who died at an age of 80 years or over. Age at first childbirth was lowest in women who died early and highest for women who died at the oldest ages. When account was taken only of women who had reached menopause, who were aged 60 years and over, female longevity was negatively correlated with number of progeny and positively correlated with age at first childbirth. The findings show that human life histories involve a trade-off between longevity and reproduction.
Article
We use the Weibull model to characterize initial (extrinsic) mortality rates (m(0)) and rate of increase in mortality with age (omega) for natural and captive populations of birds and mammals. Weibull parameters can be estimated for small samples of ages at death by constructing survival curves and fitting the Weibull model by nonlinear least-squares regression. Both m(0) and omega decrease in captivity, on average, and omega bears a strong relationship to m(0), as it does in nature, irrespective of body mass or differences between birds and mammals. Rate of aging is most closely related to brain size in birds and to rate of postnatal growth in mammals. It is not related to duration of embryonic development, body size independently of brain size, or genome size. We suggest that causes of extrinsic mortality in nature may be replaced in captivity by intrinsically controlled causes of mortality related to processes that regulate the rate of aging.
Article
There is considerable controversy over the causes of the completed fertility transitions that occurred in most industrial countries from 1870 to 1930 and the “new” fertility transitions that are currently underway in the developing world. New data and empirical analyses of both historical and contemporary fertility declines have weakened the standard theory of the demographic transition, but none of the plethora of new theories of fertility change have emerged as hegemonie or as alternative guides to empirical research. The vast body of empirical evidence on the origins, speed, and correlates of fertility declines in different historical and geographical settings shows more diversity than a simple theory of fertility change would predict. The challenge for the field is to develop a common theoretical framework that will accommodate the diversity of historical paths from high to low fertility.
Article
The social consequences of extending the human life span might be quite bad; perhaps the worst outcome is that power could be concentrated into ever fewer hands, as those who wield it gave way more slowly to death and disease. But the worry that more life would damage individuals' quality of life is not persuasive. Depending on what the science of aging makes possible, and on how people plan their lives, longer life might even facilitate a richer and deeper life.
Article
Near-global fertility decline began in the 1960s, and from the 1980s an increasing number of European countries and some Asian ones achieved very low fertility (total fertility below 1.5) with little likelihood of completed cohort fertility reaching replacement level. Earlier theory aiming at explaining this phenomenon stressed the incompatibility between post-industrial society and behaviour necessary for population replacement. Recent theory has been more specific, often concentrating on the current Italian or Spanish situations or on the contrast between them and the situation in either Scandinavia or the English-speaking countries, or both. Such an approach ignores important evidence, especially that from German-speaking populations. The models available concentrate on welfare systems and family expenses, omitting circumstances that may be unique to individual countries or longer-term factors that may be common to all.
Article
The purpose of this study is to test the prediction of the evolutionary theory of aging that human longevity comes with the cost of impaired reproductive success (higher infertility rates). Our validation study is based on the analysis of particularly reliable genealogical records for European aristocratic families using a logistic regression model with childlessness as a dependent (outcome) variable, and woman's life span, year of birth, age at marriage, husband's age at marriage, and husband's life span as independent (predictor) variables. We found that the woman's exceptional longevity did not increase her chances of being infertile. It appears that the previous reports by other authors of high infertility among long-lived women (up to 50% infertility) are related to incomplete data, that is, births of children not reported. Thus, the concept of the high cost of infertility for human longevity is not supported by the data when these data are carefully cross-checked, cleaned, and reanalyzed.
Article
Death, Robert Freitas insists, is “an outrage”. In an essay based on his speech at the Fifth Alcor Conference on Extreme Life Extension in 2002, Freitas, a researcher at the Institute for Molecular Manufacturing (Los Altos, CA, USA), said, “While you were reading this sentence, a dozen people just died, worldwide. There. Another dozen people have perished. I think this is an outrage. I want to tell you why I think so, and what nanomedicine can do to help” (Freitas, 2002). Clearly, Freitas is not someone inclined to ‘go gentle into that good night’. Advancing his argument for ‘dechronification’, he advocates the development of chromosome replacement therapy, tissue engineering, nanomedicine, nanorobotics, cellular repair devices and various genetic modifications. Aubrey de Grey, a geneticist at Cambridge University (UK) and an emerging anti‐ageing media guru, is equally offended at the prospect of death. “Ageing really is barbaric. It shouldn‘t be allowed. I don't need an ethical argument. I don‘t need any argument. It's visceral. To let people die is bad” (Gorman, 2003). Freitas and de Grey are optimistic that death can be defeated. Freitas is confident that nanomedicine offers the best prospect for combating finitude. De Grey insists on a multi‐pronged assault on ageing through “engineered negligible senescence” (de Grey et al , 2002a,b). © Getty ![][1] Outspoken advocates of transhumanism, Freitas and de Grey belong to a highly visible but rather marginal community that regards death as a “bad lifestyle option” (Heard, 1997). They seek to conquer and defeat ageing once and for all. This goes hand in hand with an increasing obsession in affluent societies for staying youthful. There is now a billion‐dollar market in products that purport to overcome ageing (Heard, 1997; Duenwald, 2004; Pearce, 2005). The possibility of effective anti‐ageing medicines has already created intense … [1]: /embed/graphic-1.gif
Article
It has long been held that food restriction extends the life span of rodents and other species by decreasing caloric intake and slowing the rate of aging. Recent findings challenge these concepts. This review assesses these controversial issues. The conclusion is that caloric restriction underlies the life extension of rats, but not of Drosophila. Mortality characteristics show that food restriction slows the rate of aging of rats and, in some studies, of mice. However, in other mouse studies and in Drosophila, mortality characteristics have been interpreted as indicating that it delays the start but does not slow the rate of aging; the author believes that this interpretation is faulty. These differences in mortality responses to food restriction provide a potentially powerful tool for uncovering basic mechanisms underlying its life-prolonging action. A hypothesis is presented for use in the search for these mechanisms.
Article
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.
Research into aging: Should it be guided by the interests of present individuals, future individuals, or the species
  • Peter Singer
Singer, Peter. 1991. Research into aging: Should it be guided by the interests of present individuals, future individuals, or the species. In Life span extension: Consequences and open questions, ed. Frédéric C. Ludwig, 132-145. New York: Springer.
1872. An essay on the principle of population or a view of its past and present effects on human happiness: An inquiry into our prospects respecting the future removal or mitigation of the evils which it occasions
  • Thomas Malthus
  • Robert
  • Thomas Robert Malthus
Malthus, Thomas Robert. 1872. An essay on the principle of population or a view of its past and present effects on human happiness: An inquiry into our prospects respecting the future removal or mitigation of the evils which it occasions. London: Reeves and Turner.
Towards longer lives: The ethical implications of life extension by calorie restriction (CR) and CR mimetics
  • Christopher Wareham
Wareham, Christopher. 2013. Towards longer lives: The ethical implications of life extension by calorie restriction (CR) and CR mimetics. Milan: Universita Degli Studi di Milano.
Health implications of novel life extending drugs
  • Christopher Wareham
Wareham, Christopher. 2012. Health implications of novel life extending drugs. International Journal of Design and Innovation Research 7: 1-12.
Caloric restriction delays disease onset and mortality in rhesus monkeys
  • Ricki J Colman
  • M Rozalyn
  • Sterling C Anderson
  • Johnson
Colman, Ricki J., Rozalyn M. Anderson, Sterling C. Johnson, et al. 2009. Caloric restriction delays disease onset and mortality in rhesus monkeys. Science 325: 201-204.