The Ecologies of Human Immune Function Thomas W. McDade
Abstract
Immune function is notoriously complex, and current biomedical research elaborates this complexity by focusing on the cellular and molecular mechanisms that characterize immune defenses. However, the human immune system is a product of natural selection that develops and functions in whole organisms that are integral parts of their surrounding environments. A population-level, cross-cultural, adaptationist perspective is therefore a necessary complement to the micro levels of analysis currently favored by biomedical immunology.
Prior field-based research on human immunity is reviewed to demonstrate the relevance of cultural ecological factors, with an emphasis on the ecologies of nutrition, infectious disease, reproduction, and psychosocial stress. Common themes and anthropological contributions are identified in an attempt to promote future research in human ecological immunology that integrates theory and method for a more contextualized understanding of this important physiological system.
Tuesday, May 30, 2006
Life History Theory and the Immune System
Ok, after a short, unavoidable, absence I am now back at work. Kaplan argues that the two most energy intense components of the human body are the brain and the immune system. This paper addresses some of the implications of immune system demands in the presence of nutritional constraints:
Life History Theory and the Immune System: Steps Toward a Human Ecological Immunology
Thomas W. MCDade
ABSTRACT Within anthropology and human biology, there is growing interest in immune function and its importance to the ecology of human health and development. Biomedical research currently dominates our understanding of immunology, and this paper seeks to highlight the potential contribution of a population-based, ecological
approach to the study of human immune function. Concepts from life-history theory are applied to highlight the major challenges and demands that are likely to shape
immune function in a range of ecological contexts. Immune function is a major component of maintenance effort, and since resources are limited, trade-offs are expected between investment in maintenance and other critical life-history functions involving growth and reproduction.
An adaptationist, life-history perspective helps make sense of the unusual developmental trajectory of immune tissues, and emphasizes that this complex system is designed to incorporate information from the surrounding ecology to guide its development. As a result, there is substantial population variation in immune development and function that is not considered by current biomedical approaches. In an attempt to construct a framework for understanding this variation, immune development is considered in relation to the competing life-history demands
that define gestation, infancy, childhood, adolescence, and adulthood. Each life stage poses a unique set of adaptive challenges, and a series of hypotheses is proposed
regarding their implications for immune development and function. Research in human ecological immunology is in its earliest stages, but this is a promising area
of exploration, and one in which anthropology is wellpositioned to make important contributions. Yrbk Phys Anthropol 46:100–125, 2003. © 2003 Wiley-Liss, Inc.
Life History Theory and the Immune System: Steps Toward a Human Ecological Immunology
Thomas W. MCDade
ABSTRACT Within anthropology and human biology, there is growing interest in immune function and its importance to the ecology of human health and development. Biomedical research currently dominates our understanding of immunology, and this paper seeks to highlight the potential contribution of a population-based, ecological
approach to the study of human immune function. Concepts from life-history theory are applied to highlight the major challenges and demands that are likely to shape
immune function in a range of ecological contexts. Immune function is a major component of maintenance effort, and since resources are limited, trade-offs are expected between investment in maintenance and other critical life-history functions involving growth and reproduction.
An adaptationist, life-history perspective helps make sense of the unusual developmental trajectory of immune tissues, and emphasizes that this complex system is designed to incorporate information from the surrounding ecology to guide its development. As a result, there is substantial population variation in immune development and function that is not considered by current biomedical approaches. In an attempt to construct a framework for understanding this variation, immune development is considered in relation to the competing life-history demands
that define gestation, infancy, childhood, adolescence, and adulthood. Each life stage poses a unique set of adaptive challenges, and a series of hypotheses is proposed
regarding their implications for immune development and function. Research in human ecological immunology is in its earliest stages, but this is a promising area
of exploration, and one in which anthropology is wellpositioned to make important contributions. Yrbk Phys Anthropol 46:100–125, 2003. © 2003 Wiley-Liss, Inc.
Monday, May 15, 2006
'Natural' Fertility
Between natural fertility and intentional control: evidence from the African Demographic and Health Surveys, Jennifer Johnson-Hanks
This article examines patterns of marital fertility in age and time (AFMFR and AIBI by parity) from 18 African Demographic and Health Surveys, and compares them to the patterns found in North America and Europe in the seventeenth through nineteenth centuries. On the basis of such birth spacing and timing data, demographers have long made inferences about reproductive intentions and reproductive behavior (e.g. Coale 1973, 1986; Knodel 1977, 1987). In the DHS data, however, we have information about both intentions and reproductive practice on the one hand, and birth spacing and timing on the other. Thus, it is possible to compare inferences about intentional states from population rates to selfreported intentional states themselves. The article demonstrates that the shape of age-specific marital fertility rates and the patterns of interbirth intervals among women in 18 African countries who assert that they have no intention to limit fertility and have never used contraception differ quite substantially from that of 19th century Europe and North America. On the basis of this and related data, the article argues against the widely assumed indexical relationship between specific population-level reproductive patterns and individual intentions. As the social organization of reproduction in contemporary Africa differs fundamentally from that of historical Europe, the quantitative methods
developed in that context are inapplicable to Africa.
This article examines patterns of marital fertility in age and time (AFMFR and AIBI by parity) from 18 African Demographic and Health Surveys, and compares them to the patterns found in North America and Europe in the seventeenth through nineteenth centuries. On the basis of such birth spacing and timing data, demographers have long made inferences about reproductive intentions and reproductive behavior (e.g. Coale 1973, 1986; Knodel 1977, 1987). In the DHS data, however, we have information about both intentions and reproductive practice on the one hand, and birth spacing and timing on the other. Thus, it is possible to compare inferences about intentional states from population rates to selfreported intentional states themselves. The article demonstrates that the shape of age-specific marital fertility rates and the patterns of interbirth intervals among women in 18 African countries who assert that they have no intention to limit fertility and have never used contraception differ quite substantially from that of 19th century Europe and North America. On the basis of this and related data, the article argues against the widely assumed indexical relationship between specific population-level reproductive patterns and individual intentions. As the social organization of reproduction in contemporary Africa differs fundamentally from that of historical Europe, the quantitative methods
developed in that context are inapplicable to Africa.
Department of Wow
I have obviously been reading too much evolutionary biology lately. Reading through this very interesting paper by John Hobcraft I came across this intriguing paragraph:
Our emotions play an important part in any long-term relationship. A ‘good’ partnership can successfully meet many of our basic needs for sex, for nurture, and for intimacy (Panksepp, 1998). On the other hand intimate partnerships are too often associated with emotions of fear, disgust, or anger (Fiske 2004). Demographers need to engage with neuroscience and gain a better understanding of the role of emotions in relationships (see also Massey 2002). Moreover, we need to pay attention to some emergent suggestions that pair-bonding and love generate lasting changes in brain structure (Young 2003). In other words, the key importance of feedback loops in relationship formation and breakdown need to be included in our consideration.
"emergent suggestions that pair-bonding and love generate lasting changes in brain structure" hmmm, I thought. So I dug out the reference and went looking for Young:
Young, L.J. 2003. The neural basis of pair bonding in a monogamous species: a model for understanding the biological basis of human behavior, in K.W. Wachter and R.A. Bulatao (eds.) Offspring: Human Fertility Behavior in Biodemographic Perspective. Washington D.C.: National Academy Press.
where I found:
Studies of voles have produced an exciting hypothesis that suggests pair bond formation is regulated by the same brain regions involved in the actions of drugs of abuse. These so-called reward circuits are regions of the brain that regulate feelings of pleasure and reward. These regions are activated by a neurotransmitter called dopamine, which is increased in the brain after taking cocaine and amphetamines. Those experiencing love of-ten report feelings of euphoria when intimate with their partners, and these feelings are often reported as being similar to being “high.” There is some scientific evidence that these reward circuits may in fact be involved in the psychobiology of love. One study examined brain activation in people while viewing photographs of someone to whom the subject reported being deeply in love. Brain activity was also determined while these same subjects viewed photographs of other familiar individuals. The authors reported that viewing photographs of their lovers elicited brain activation that was remarkably similar to that seen in other studies after drug consumption (Bartels and Zeki, 2000). This suggests that perhaps similar neural circuits are used to facilitate pair bonding in voles and humans. Perhaps the saying “love is an addiction” has biological support.
The biological basis of the pair bond in humans may change with time. In the early years of a relationship, love is experienced as an incredibly intense sensation that often drives the behavior of the individual. People experience a euphoria that may be similar to that experienced by drugs of addiction, and this experience undoubtedly has a specific neurochemistry underlying it. The individuals in these relationships are consumed by thoughts of being with their partner, often at the expense of other relationships. However, often in later years of a marriage, the nature of this bond changes and becomes less visceral and more a relationship of codependence. Perhaps for our primitive ancestors, the transition between these two types of love, which would occur after the offspring of the relationship are less dependent on the mother, would mark the dissolution of the relationship.
Hmmm, hmmmm
Our emotions play an important part in any long-term relationship. A ‘good’ partnership can successfully meet many of our basic needs for sex, for nurture, and for intimacy (Panksepp, 1998). On the other hand intimate partnerships are too often associated with emotions of fear, disgust, or anger (Fiske 2004). Demographers need to engage with neuroscience and gain a better understanding of the role of emotions in relationships (see also Massey 2002). Moreover, we need to pay attention to some emergent suggestions that pair-bonding and love generate lasting changes in brain structure (Young 2003). In other words, the key importance of feedback loops in relationship formation and breakdown need to be included in our consideration.
"emergent suggestions that pair-bonding and love generate lasting changes in brain structure" hmmm, I thought. So I dug out the reference and went looking for Young:
Young, L.J. 2003. The neural basis of pair bonding in a monogamous species: a model for understanding the biological basis of human behavior, in K.W. Wachter and R.A. Bulatao (eds.) Offspring: Human Fertility Behavior in Biodemographic Perspective. Washington D.C.: National Academy Press.
where I found:
Studies of voles have produced an exciting hypothesis that suggests pair bond formation is regulated by the same brain regions involved in the actions of drugs of abuse. These so-called reward circuits are regions of the brain that regulate feelings of pleasure and reward. These regions are activated by a neurotransmitter called dopamine, which is increased in the brain after taking cocaine and amphetamines. Those experiencing love of-ten report feelings of euphoria when intimate with their partners, and these feelings are often reported as being similar to being “high.” There is some scientific evidence that these reward circuits may in fact be involved in the psychobiology of love. One study examined brain activation in people while viewing photographs of someone to whom the subject reported being deeply in love. Brain activity was also determined while these same subjects viewed photographs of other familiar individuals. The authors reported that viewing photographs of their lovers elicited brain activation that was remarkably similar to that seen in other studies after drug consumption (Bartels and Zeki, 2000). This suggests that perhaps similar neural circuits are used to facilitate pair bonding in voles and humans. Perhaps the saying “love is an addiction” has biological support.
The biological basis of the pair bond in humans may change with time. In the early years of a relationship, love is experienced as an incredibly intense sensation that often drives the behavior of the individual. People experience a euphoria that may be similar to that experienced by drugs of addiction, and this experience undoubtedly has a specific neurochemistry underlying it. The individuals in these relationships are consumed by thoughts of being with their partner, often at the expense of other relationships. However, often in later years of a marriage, the nature of this bond changes and becomes less visceral and more a relationship of codependence. Perhaps for our primitive ancestors, the transition between these two types of love, which would occur after the offspring of the relationship are less dependent on the mother, would mark the dissolution of the relationship.
Hmmm, hmmmm
Sunday, May 14, 2006
Russian Mortality
Autopsy on an Empire: Understanding Mortality in Russia and the Former Soviet Union, Elizabeth Brainerd, David M. Cutler
"Male life expectancy at birth fell by over six years in Russia between 1989 and 1994. Many other countries of the former Soviet Union saw similar declines, and female life
expectancy fell as well. Using cross-country and Russian household survey data, we assess six possible explanations for this upsurge in mortality. Most find little support in the data: the deterioration of the health care system, changes in diet and obesity, and material deprivation fail to explain the increase in mortality rates. The two factors that do appear to be important are alcohol consumption, especially as it relates to external causes of death (homicide, suicide, and accidents) and stress associated with a poor outlook for the future. However, a large residual remains to be explained."
"Male life expectancy at birth fell by over six years in Russia between 1989 and 1994. Many other countries of the former Soviet Union saw similar declines, and female life
expectancy fell as well. Using cross-country and Russian household survey data, we assess six possible explanations for this upsurge in mortality. Most find little support in the data: the deterioration of the health care system, changes in diet and obesity, and material deprivation fail to explain the increase in mortality rates. The two factors that do appear to be important are alcohol consumption, especially as it relates to external causes of death (homicide, suicide, and accidents) and stress associated with a poor outlook for the future. However, a large residual remains to be explained."
Modernisation and the Demographic Transition
Economic Development, Formation of Human Capital and the Demographic Transition: Southern Sweden 1750 – 1900. Tommy Bengtsson & Patrick Svensson.
Modernisation caused a demographic transition from high mortality to low mortality and, later from high fertility, to low fertility. Short-term variations in mortality and fertility meanwhile diminished. The delay in the fertility decline was due to the fact that the social norms influencing fertility only change slowly. This is the way the theory of the demographic transition was formulated in the 1950s by Davis and Notestein. For some time, it was considered as a cornerstone of social science but was later questioned both from theoretical and empirical points of view. Still the concept ‘demographic transition’ is widely used to describe the change from high to low rates of mortality and fertility.
Bengtsson and Ohlsson (1994), in their reformation of the theory, argue that while the causal mechanisms are correct, the dating of the theory is wrong. They argue that the start of the mortality decline did not mark the beginning of the demographic transition. The initial decline, which shows great similarity throughout Europe despite various stages of economic development, was instead spontaneous (Fridlizius 1984, Perrenoud 1984, Schofield 1984) and similar changes have taken place many times in the past. But instead of a rebound to high mortality, which had been the pattern of the past, mortality continued to decline. This marks the start of the demographic transition and this was the result of modernisation. In this way redefining the time for the onset of the demographic transition, to the mid-nineteenth century or shortly before, the lag between modernisation and the fertility decline is also narrowed down to a couple of decades and supersedes the assumption of slowly changing social norms in regulating family size.
Modernisation caused a demographic transition from high mortality to low mortality and, later from high fertility, to low fertility. Short-term variations in mortality and fertility meanwhile diminished. The delay in the fertility decline was due to the fact that the social norms influencing fertility only change slowly. This is the way the theory of the demographic transition was formulated in the 1950s by Davis and Notestein. For some time, it was considered as a cornerstone of social science but was later questioned both from theoretical and empirical points of view. Still the concept ‘demographic transition’ is widely used to describe the change from high to low rates of mortality and fertility.
Bengtsson and Ohlsson (1994), in their reformation of the theory, argue that while the causal mechanisms are correct, the dating of the theory is wrong. They argue that the start of the mortality decline did not mark the beginning of the demographic transition. The initial decline, which shows great similarity throughout Europe despite various stages of economic development, was instead spontaneous (Fridlizius 1984, Perrenoud 1984, Schofield 1984) and similar changes have taken place many times in the past. But instead of a rebound to high mortality, which had been the pattern of the past, mortality continued to decline. This marks the start of the demographic transition and this was the result of modernisation. In this way redefining the time for the onset of the demographic transition, to the mid-nineteenth century or shortly before, the lag between modernisation and the fertility decline is also narrowed down to a couple of decades and supersedes the assumption of slowly changing social norms in regulating family size.
Saturday, May 13, 2006
Monique Borgerhoff Mulder
I'd forgotten about Monique. You can find a lot of very useful material on her website, here.
Maimonides For The Hard of Hearing
Controversies in the evolutionary social sciences: a guide for the perplexed. Eric A. Smith, Monique Borgerhoff Mulder and Kim Hill.
It is 25 years since modern evolutionary ideas were first applied extensively to human behavior, jump-starting a field of study once known as ‘sociobiology’. Over the years, distinct styles of evolutionary analysis have emerged within the social sciences. Although there is considerable complementarity between approaches that emphasize the study of psychological mechanisms and those that focus on adaptive fit to environments, there are also substantial theoretical and methodological differences. These differences have generated a recurrent debate that is now exacerbated by growing popular media attention to evolutionary human behavioral studies. Here,we provide a guide to current controversies surrounding evolutionary studies of human social behavior, emphasizing theoretical and methodological issues.We conclude that a greater use of formal models, measures of current fitness costs and benefits, and attention to adaptive tradeoffs, will enhance the power and reliability of evolutionary analyses of human social behavior.
It is 25 years since modern evolutionary ideas were first applied extensively to human behavior, jump-starting a field of study once known as ‘sociobiology’. Over the years, distinct styles of evolutionary analysis have emerged within the social sciences. Although there is considerable complementarity between approaches that emphasize the study of psychological mechanisms and those that focus on adaptive fit to environments, there are also substantial theoretical and methodological differences. These differences have generated a recurrent debate that is now exacerbated by growing popular media attention to evolutionary human behavioral studies. Here,we provide a guide to current controversies surrounding evolutionary studies of human social behavior, emphasizing theoretical and methodological issues.We conclude that a greater use of formal models, measures of current fitness costs and benefits, and attention to adaptive tradeoffs, will enhance the power and reliability of evolutionary analyses of human social behavior.
Friday, May 12, 2006
A Short Story
Is short height really a risk factor for coronary heart disease and stroke mortality? A review, Thomas T. Samaras, Harold Elrick, Lowell H. Storms, Med Sci Monit, 2004; 10(4): RA63-76.
For the past 30 years, Thomas T. Samaras and his associates Dr. Elrick and Dr. Storms have published 16 papers in scientific and medical journals on the positive aspects of shorter height and smaller body size. Mr. Samaras is the Director and Senior Researcher at Reventropy Associates in San Diego, California. These have included papers in the Bulletin of the World Health Organization, Journal of the National Medical Association, Life Sciences, Western Journal of Medicine, Journal of the Washington Academy of Sciences, Acta Pediatrica and Ageing Research Reviews. This page presents a summary of their findings.
For the past 30 years, Thomas T. Samaras and his associates Dr. Elrick and Dr. Storms have published 16 papers in scientific and medical journals on the positive aspects of shorter height and smaller body size. Mr. Samaras is the Director and Senior Researcher at Reventropy Associates in San Diego, California. These have included papers in the Bulletin of the World Health Organization, Journal of the National Medical Association, Life Sciences, Western Journal of Medicine, Journal of the Washington Academy of Sciences, Acta Pediatrica and Ageing Research Reviews. This page presents a summary of their findings.
Thursday, May 04, 2006
Histology
FUNCTION
The primary function of the female reproductive system is reproduction, which includes
* the production of ova
* the transportation of ova from the ovary to the site of fertilization
* transportation of spermatozoa from the point of deposition in the female tract to the site of fertilization
* nourishment of the developing embryo and fetus
* parturition and nourishment of the infant.
continue reading
The primary function of the female reproductive system is reproduction, which includes
* the production of ova
* the transportation of ova from the ovary to the site of fertilization
* transportation of spermatozoa from the point of deposition in the female tract to the site of fertilization
* nourishment of the developing embryo and fetus
* parturition and nourishment of the infant.
continue reading
Sunday, April 30, 2006
Two Quotes
Below are two quotes, one from new growth theorist Paul Romer, the other from two anthropologists studying development processes in Ethiopia. In both examples a simple energy saving is made, but the outcome is quite different, in the former case living standards per capita rise, in the second more children are produced, and the nutritional status of each surviving child deteriorates. The difference between the Mathusian-regime and the modern economic growth one couldn't be more clearly illustrated.
Romer, Paul, 2007: "Economic Growth," The Concise Encyclopedia of Economics, David R. Henderson, ed. Liberty Fund (Forthcoming)
"Economic growth occurs whenever people take resources and rearrange them in ways that are more valuable. A useful metaphor for production in an economy comes from the kitchen. To create valuable final products, we mix inexpensive ingredients together according to a recipe. The cooking one can do is limited by the supply of ingredients, and most cooking in the economy produces undesirable side effects. If economic growth could be achieved only by doing more and more of the same kind of cooking, we would eventually run out of raw materials and suffer from unacceptable levels of pollution and nuisance. Human history teaches us, however, that economic growth springs from better recipes, not just from more cooking. New recipes generally produce fewer unpleasant side effects and generate more economic value per unit of raw material".
"Take one small example. In most coffee shops, you can now use the same size lid for small, medium, and large cups of coffee. That wasn’t true as recently as 1995. That small change in the geometry of the cups means that a coffee shop can serve customers at lower cost. Store owners need to manage the inventory for only one type of lid. Employees can replenish supplies more quickly throughout the day. Customers can get their coffee just a bit faster. Such big discoveries as the transistor, antibiotics, and the electric motor attract most of the attention, but it takes millions of little discoveries like the new design for the cup and lid to double average income in a nation."
An Energy-Saving Development Initiative Increases Birth Rate and Childhood Malnutrition in Rural Ethiopia, Mhairi A. Gibson, Ruth Mace
"In the villages of Hitosa and Dodota subdistricts......Water shortages, particularly during the dry season months (December to April) can be severe. Mean precipitation is less than 700 mm and there are no perennial rivers. Traditionally, women have borne the brunt of water collection, some transporting the water on their backs in clay pots (insera) for distances of up to 30 km. However, between 1996 and 2000 some villages benefited from a water development scheme (the Hitosa Gravity Water Supply Scheme), which has reduced both the energy and time women spent carrying water following the installation of village-level tap stands (Table 1). Women state their time spent carrying water has been reduced from around three hours to 15 minutes during the driest months. This time is now employed in more social activities, as well as standing in line at the tap stands."
"This study is the first, to our knowledge, to demonstrate a link between a specific technological intervention and an increase in birth rate and decrease in mortality at the village level. The increased birth rate is likely to be mediated by improvements in women's workloads, brought about by reducing energetic expenditure on water collection, since women's nutritional levels, breast feeding practices, and health do not vary (Table 5). Female health outcomes (nutritional status and morbidity levels) do not appear to be influenced by reduced workloads, lending support to the idea that women's surplus energy is diverted towards reproduction. Increased levels of child survival are likely to relate to improvements in the quality and quantity of water supply [47,48] and greater opportunities for direct maternal childcare. We propose that the energy saved by a new development technology is being diverted to enhance fertility and reduce mortality; however, since the underlying resources in the system are limited, this comes at the cost of an increase in childhood malnutrition."
Romer, Paul, 2007: "Economic Growth," The Concise Encyclopedia of Economics, David R. Henderson, ed. Liberty Fund (Forthcoming)
"Economic growth occurs whenever people take resources and rearrange them in ways that are more valuable. A useful metaphor for production in an economy comes from the kitchen. To create valuable final products, we mix inexpensive ingredients together according to a recipe. The cooking one can do is limited by the supply of ingredients, and most cooking in the economy produces undesirable side effects. If economic growth could be achieved only by doing more and more of the same kind of cooking, we would eventually run out of raw materials and suffer from unacceptable levels of pollution and nuisance. Human history teaches us, however, that economic growth springs from better recipes, not just from more cooking. New recipes generally produce fewer unpleasant side effects and generate more economic value per unit of raw material".
"Take one small example. In most coffee shops, you can now use the same size lid for small, medium, and large cups of coffee. That wasn’t true as recently as 1995. That small change in the geometry of the cups means that a coffee shop can serve customers at lower cost. Store owners need to manage the inventory for only one type of lid. Employees can replenish supplies more quickly throughout the day. Customers can get their coffee just a bit faster. Such big discoveries as the transistor, antibiotics, and the electric motor attract most of the attention, but it takes millions of little discoveries like the new design for the cup and lid to double average income in a nation."
An Energy-Saving Development Initiative Increases Birth Rate and Childhood Malnutrition in Rural Ethiopia, Mhairi A. Gibson, Ruth Mace
"In the villages of Hitosa and Dodota subdistricts......Water shortages, particularly during the dry season months (December to April) can be severe. Mean precipitation is less than 700 mm and there are no perennial rivers. Traditionally, women have borne the brunt of water collection, some transporting the water on their backs in clay pots (insera) for distances of up to 30 km. However, between 1996 and 2000 some villages benefited from a water development scheme (the Hitosa Gravity Water Supply Scheme), which has reduced both the energy and time women spent carrying water following the installation of village-level tap stands (Table 1). Women state their time spent carrying water has been reduced from around three hours to 15 minutes during the driest months. This time is now employed in more social activities, as well as standing in line at the tap stands."
"This study is the first, to our knowledge, to demonstrate a link between a specific technological intervention and an increase in birth rate and decrease in mortality at the village level. The increased birth rate is likely to be mediated by improvements in women's workloads, brought about by reducing energetic expenditure on water collection, since women's nutritional levels, breast feeding practices, and health do not vary (Table 5). Female health outcomes (nutritional status and morbidity levels) do not appear to be influenced by reduced workloads, lending support to the idea that women's surplus energy is diverted towards reproduction. Increased levels of child survival are likely to relate to improvements in the quality and quantity of water supply [47,48] and greater opportunities for direct maternal childcare. We propose that the energy saved by a new development technology is being diverted to enhance fertility and reduce mortality; however, since the underlying resources in the system are limited, this comes at the cost of an increase in childhood malnutrition."
Demography And Development
Development and Demography: A Relationship That Requires Research Editorial, The PLoS Medicine Editors
An Energy-Saving Development Initiative Increases Birth Rate and Childhood Malnutrition in Rural Ethiopia, Mhairi A. Gibson, Ruth Mace
ABSTRACT
Evolutionary life history theory predicts that, in the absence of contraception, any enhancement of maternal condition can increase human fertility. Energetic trade-offs are likely to be resolved in favour of maximizing reproductive success rather than health or longevity. Here we find support for the hypothesis that development initiatives designed to improve maternal and child welfare may also incur costs associated with increased family sizes if they do not include a family planning component.
This study is, to our knowledge, the first to demonstrate a link between a technological development intervention and an increase in both birth rate and childhood malnutrition. Women's nutritional status was not improved by the energy-saving technology, because energy was diverted into higher birth rates. We argue that the contribution of biological processes to increased birth rates in areas of the developing world without access to modern contraception has been overlooked. This highlights the continued need for development programmes to be multisectoral, including access to and promotion of contraception.
Energetics and Reproductive Effort PETER T. ELLISON, AMERICAN JOURNAL OF HUMAN BIOLOGY 15:342–351 (2003)
Natural selection favors the optimal allocation of energy and other limiting
resources to reproduction. Human reproductive physiology displays characteristic patterns that can be viewed as mechanisms that help optimize reproductive effort in the face of environmental energetic constraints. Female ovarian function is particularly sensitive to energy balance and energy flux, resulting in a synchronization of conception with favorable energetic conditions. Reproductive effort during gestation is highly buffered from environmental energetic constraints, but the duration of gestation and final birthweight are both very sensitive to maternal energy availability. Milk production during lactation is relatively buffered from maternal energetic constraints as well, but the duration of lactational amenorrhea is sensitive to the relative metabolic load of lactation. Male gamete production is very insensitive to energetic constraints, but variation in testosterone production in response to both age and longer-lasting energetic conditions contributes to the modulation of somatic and behavioral aspects of male reproductive effort, aspects that are more energetically costly for a male. There is also new evidence that testosterone may also help to modulate the trade-off between male parenting and mating effort.
An Energy-Saving Development Initiative Increases Birth Rate and Childhood Malnutrition in Rural Ethiopia, Mhairi A. Gibson, Ruth Mace
ABSTRACT
Evolutionary life history theory predicts that, in the absence of contraception, any enhancement of maternal condition can increase human fertility. Energetic trade-offs are likely to be resolved in favour of maximizing reproductive success rather than health or longevity. Here we find support for the hypothesis that development initiatives designed to improve maternal and child welfare may also incur costs associated with increased family sizes if they do not include a family planning component.
This study is, to our knowledge, the first to demonstrate a link between a technological development intervention and an increase in both birth rate and childhood malnutrition. Women's nutritional status was not improved by the energy-saving technology, because energy was diverted into higher birth rates. We argue that the contribution of biological processes to increased birth rates in areas of the developing world without access to modern contraception has been overlooked. This highlights the continued need for development programmes to be multisectoral, including access to and promotion of contraception.
Energetics and Reproductive Effort PETER T. ELLISON, AMERICAN JOURNAL OF HUMAN BIOLOGY 15:342–351 (2003)
Natural selection favors the optimal allocation of energy and other limiting
resources to reproduction. Human reproductive physiology displays characteristic patterns that can be viewed as mechanisms that help optimize reproductive effort in the face of environmental energetic constraints. Female ovarian function is particularly sensitive to energy balance and energy flux, resulting in a synchronization of conception with favorable energetic conditions. Reproductive effort during gestation is highly buffered from environmental energetic constraints, but the duration of gestation and final birthweight are both very sensitive to maternal energy availability. Milk production during lactation is relatively buffered from maternal energetic constraints as well, but the duration of lactational amenorrhea is sensitive to the relative metabolic load of lactation. Male gamete production is very insensitive to energetic constraints, but variation in testosterone production in response to both age and longer-lasting energetic conditions contributes to the modulation of somatic and behavioral aspects of male reproductive effort, aspects that are more energetically costly for a male. There is also new evidence that testosterone may also help to modulate the trade-off between male parenting and mating effort.
Saturday, April 29, 2006
Crises and Child Health Outcomes
Crises and Child Health Outcomes, The Impacts of Economic and Drought/smoke Crises on Infant Mortality and Birthweight in Indonesia. Pungpond Rukumnuaykit, Michigan State University, 2003.
This paper examines the impacts of the recent Asian financial crisis on infant mortality and birthweight in Indonesia. There have been a number of economic and policy studies focusing on impacts of economic crises on finance and production.
Although some studies provide evidence of negative impacts of economic crises on real outcomes, little is known about the impact of economic crises on child health outcomes such as changes in nutrition, child health, and mortality. Often, the association between financial and production disturbances and these outcomes are assumed (e.g. an adverse shock to production is thought to be associated with worse child health outcomes.). This paper utilizes data from the Indonesian Family Life Survey (IFLS) to examine impacts of the crises on child health outcomes directly. Specifically, we study the impacts of the crises on birthweight and infant mortality.
This paper examines the impacts of the recent Asian financial crisis on infant mortality and birthweight in Indonesia. There have been a number of economic and policy studies focusing on impacts of economic crises on finance and production.
Although some studies provide evidence of negative impacts of economic crises on real outcomes, little is known about the impact of economic crises on child health outcomes such as changes in nutrition, child health, and mortality. Often, the association between financial and production disturbances and these outcomes are assumed (e.g. an adverse shock to production is thought to be associated with worse child health outcomes.). This paper utilizes data from the Indonesian Family Life Survey (IFLS) to examine impacts of the crises on child health outcomes directly. Specifically, we study the impacts of the crises on birthweight and infant mortality.
Long Term Fluctations in Climate and Population
The history of thought seems riddled with injustice. Some names shine with a brilliance which is scarcely merited, while others, who are truly innovative and creative remain in an obscurity which is often hard to understand. My feeling is that the name Patrick R Galloway is one which belongs to this latter group.
Long-Term Fluctuations in Climate and Population in the Preindustrial Era
Patrick R. Galloway, Population and Development Review, Vol. 12, No. 1 (Mar., 1986) , pp. 1-24
Abstract
Advances in climatological history have yielded new evidence to support the view that climate has been an important influence on long-run demographic fluctuations. A model is proposed in which long-term changes in climate affect population growth directly through the effect of variations in temperature on vital rates and indirectly through its effect on food supply. The model is tested using data from western Europe, China, and middle latitude marginal areas. Over the long term, periods of cooling appear to be strongly associated with periods of depressed population growth.
Basic Patterns in Annual Variations in Fertility, Nuptiality, Mortality, and Prices in Pre-industrial Europe, Patrick R. Galloway, Population Studies, Volume 42, Number 2 / July 1988, Pages: 275 - 303
Abstract:
Examination of the responses of vital rates to variations in grain prices in nine pre-industrial European countries confirms the existence of the short-term Malthusian preventive and positive checks. The structure and magnitude of the preventive check are strikingly similar in all countries and all periods. On the other hand, the strength of the positive check varies widely and in remarkable accord with measures of economic development. The size of the positive relative to the preventive check diminishes as economic development increases. Among the countries examined, differences in the response of population growth rates to price fluctuations can be attributed primarily to differences in the strength of the positive check.
Patrick R. Galloway, Differentials in demographic responses to annual price variations in pre-revolutionary France A comparison of rich and poor areas in rouen, 1681 to 1787, European Journal of Population, Volume 2, Numbers 3-4, May 1987, Pages: 269 - 305
Abstract An examination of the annual responses of vital events to variations in wheat prices among groups of parishes in the city of Rouen from 1681 to 1787 reveals significant differences between rich and poor parishes in the strength of the preventive check. The urban poor respond to a price increase by dramatically decreasing fertility, while the fertility of the urban wealthy is virtually unaffected. An increase in prices is associated with relatively large increases in mortality, suggesting a strong positive check. However, little difference can be found between the rich and poor areas in the magnitude or timing of mortality responses to price variations.
Long-Term Fluctuations in Climate and Population in the Preindustrial Era
Patrick R. Galloway, Population and Development Review, Vol. 12, No. 1 (Mar., 1986) , pp. 1-24
Abstract
Advances in climatological history have yielded new evidence to support the view that climate has been an important influence on long-run demographic fluctuations. A model is proposed in which long-term changes in climate affect population growth directly through the effect of variations in temperature on vital rates and indirectly through its effect on food supply. The model is tested using data from western Europe, China, and middle latitude marginal areas. Over the long term, periods of cooling appear to be strongly associated with periods of depressed population growth.
Basic Patterns in Annual Variations in Fertility, Nuptiality, Mortality, and Prices in Pre-industrial Europe, Patrick R. Galloway, Population Studies, Volume 42, Number 2 / July 1988, Pages: 275 - 303
Abstract:
Examination of the responses of vital rates to variations in grain prices in nine pre-industrial European countries confirms the existence of the short-term Malthusian preventive and positive checks. The structure and magnitude of the preventive check are strikingly similar in all countries and all periods. On the other hand, the strength of the positive check varies widely and in remarkable accord with measures of economic development. The size of the positive relative to the preventive check diminishes as economic development increases. Among the countries examined, differences in the response of population growth rates to price fluctuations can be attributed primarily to differences in the strength of the positive check.
Patrick R. Galloway, Differentials in demographic responses to annual price variations in pre-revolutionary France A comparison of rich and poor areas in rouen, 1681 to 1787, European Journal of Population, Volume 2, Numbers 3-4, May 1987, Pages: 269 - 305
Abstract An examination of the annual responses of vital events to variations in wheat prices among groups of parishes in the city of Rouen from 1681 to 1787 reveals significant differences between rich and poor parishes in the strength of the preventive check. The urban poor respond to a price increase by dramatically decreasing fertility, while the fertility of the urban wealthy is virtually unaffected. An increase in prices is associated with relatively large increases in mortality, suggesting a strong positive check. However, little difference can be found between the rich and poor areas in the magnitude or timing of mortality responses to price variations.
ECONOMIC AND CULTURAL FACTORS IN DEMOGRAPHIC BEHAVIOR
ECONOMIC AND CULTURAL FACTORS IN DEMOGRAPHIC BEHAVIOR, Patrick R. Galloway, E. A. Hammel, R. D. Lee
The origins of this project were two-fold.
1. The general conclusions of the Princeton European Fertility Project (PEFP), to the effect that economic and structural factors cannot be shown to have important effects as determinants of the level of fertility or of its decline, are contrary both to intuition and to theoretical expectation.
2. The quality and local specificity of the data on Prussia c. 1849-1914 permit much closer testing of the determinants of fertility and of fertility decline than the PEFP was able to use. In order to achieve comparability across a broad range of countries with available data, PEFP was obliged to use major regional units, akin to provinces or states. However, for much of the late mediaeval and early modern periods such units were largely autarkic economies with substantial internal variation, such that the variance between such units was likely to be less than the variance within them, in respect of variables of interest. Thus, comparison between such units suffered from minimal variance in the variables of interest, other than those of national identity (including language). The data on Prussia, however, are at the Kreis level and permit much closer testing of hypotheses about the relationship between structural and demographic variables. Realization of the possibilities in the Prussian materials led Galloway to formulate an approach, which, implemented with the participation of Hammel and Lee, led to the UC Prussia Project (UCPP).
The general conclusions of the research are that socalled cultural variables, proxied by language and religion, are important determinants of the level of fertility but not of the rate of fertility decline. On the other hand, structural and economic variables are powerful determinants of the rate of fertility decline and thus in the long run must be determinants of ultimate levels of fertility. This formulation, supported by sophisticated pooled time series analysis of data of impeccable quality, is an important refinement of the conclusions of PEFP by UCPP.
The origins of this project were two-fold.
1. The general conclusions of the Princeton European Fertility Project (PEFP), to the effect that economic and structural factors cannot be shown to have important effects as determinants of the level of fertility or of its decline, are contrary both to intuition and to theoretical expectation.
2. The quality and local specificity of the data on Prussia c. 1849-1914 permit much closer testing of the determinants of fertility and of fertility decline than the PEFP was able to use. In order to achieve comparability across a broad range of countries with available data, PEFP was obliged to use major regional units, akin to provinces or states. However, for much of the late mediaeval and early modern periods such units were largely autarkic economies with substantial internal variation, such that the variance between such units was likely to be less than the variance within them, in respect of variables of interest. Thus, comparison between such units suffered from minimal variance in the variables of interest, other than those of national identity (including language). The data on Prussia, however, are at the Kreis level and permit much closer testing of hypotheses about the relationship between structural and demographic variables. Realization of the possibilities in the Prussian materials led Galloway to formulate an approach, which, implemented with the participation of Hammel and Lee, led to the UC Prussia Project (UCPP).
The general conclusions of the research are that socalled cultural variables, proxied by language and religion, are important determinants of the level of fertility but not of the rate of fertility decline. On the other hand, structural and economic variables are powerful determinants of the rate of fertility decline and thus in the long run must be determinants of ultimate levels of fertility. This formulation, supported by sophisticated pooled time series analysis of data of impeccable quality, is an important refinement of the conclusions of PEFP by UCPP.
Subscribe to:
Posts (Atom)
