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Оглавление
Введение
Трудно сказать, кто первый применил термин "популяционная физиология". В наших исследованиях он появился сам собой и настолько естественно, что у антропологов, привыкших работать на популяционном уровне, вопросов о происхождении этого словосочетания просто не возникало. Однако следует отметить, что А.В.Яблоков в 1980Нм году в своей книге "Фенетика: эволюция, популяция, признак" написал о важном общебиологическом значении эволюционного учения для исследований в популяционной экологии, популяционной физиологии и этологии. Популяционная физиология человека возникла в русле физиологической антропологии, которая на протяжении своей истории постоянно вводила в научный оборот новые признаки и методы, меняла цели и задачи, расширяла границы исследования и в итоге пришла к закономерному разделению на ряд отдельных самостоятельных научных ветвей. На сегодняшний день популяционная физиология человека представляет собой направление физиологической антропологии, которое изучает физиологическую структуру популяций в конкретных условиях среды. Появление популяционной физиологии человека – это настоятельное требование времени. Традиционные для физиологической антропологии представления далеко не всегда могли разрешить проблему интерпретации результатов, получаемых многими исследователями. Проблема трактовки накопленной информации нуждалась в определенной концепции, которая могла бы объяснить причины и механизмы наблюдаемых явлений. Актуальность возникновения популяционной физиологии человека заключается в применении концепции физиологического гомеостаза (Cannon, 1932) для объяснения стабильности и изменчивости физиологического статуса популяций: физиологический гомеостаз, его зависимость от экологических факторов, рассматривается как основной механизм, определяющий разнообразие физиологической структуры популяций, находящихся в различных средовых условиях и на разных стадиях адаптированности. В популяционной физиологии человека гомеостаз, адаптация и экологические факторы обсуждаются на популяционном уровне в комплексе их причинно-следственной связи. Методологической базой направления являются системность и целостность. Назначение предлагаемой читателю книги – обозначить пути и способы изучения любой физиологической системы на уровне популяций Homo sapiens. Кстати, популяция, как и все человечество, которое может восприниматься как один объект, представляет собой систему (Капица, 1999). Идея целостности – основное в содержании монографии: физиологическая и морфофизиологическая структура популяции рассматриваются исключительно как целостное образование, которое обеспечивается устойчивыми связями частей общей системы. Следует заметить, что целостность декларируется в биологии проблемой XXI века (Белоусов, 2001). Книга имеет многоплановый характер. По этой причине отсутствует единый литературный обзор. Сведения из литературных источников приводятся в разделах "история вопроса" и при сравнительном анализе наших результатов. Эти источники составляют обширную библиографию, которая может оказаться полезной для исследователей, интересующихся проблемами, обсуждаемыми в монографии. В первой главе анализируется большой фактический материал по уровням отдельных физиологических показателей крови, собранный в разных регионах земного шара. Представленная информация несет определенную смысловую нагрузку: для понимания существующего разнообразия необходима единая концепция. В главе подробно изложены теоретические и методологические основы популяционной физиологии человека, обозначен предмет, сформулированы цели и задачи нового направления физиологической антропологии. Вторая глава посвящена описанию материалов и методов. Для создания монографии наипервейшее значение имели экспедиции. В книгу вошли материалы, собранные на Чукотке и Камчатке, в горах Памира и песках Каракумов, в Хакасии и Ярославской области. В методическом разделе с привлечением литературных данных обоснована целесообразность применения определенных методик и уделено большое внимание их сопоставимости. Третья глава является основной в книге. Обсуждаются три популяционные модели физиологического гомеостаза: в относительно комфортной зоне, в среде с обратимыми изменениями и в экстремальных экологических условиях, вызывающих постоянный физиологический стресс. Системный подход к физиологическому статусу популяций как к целостной структуре дает интегративную информацию о физиологическом гомеостазе популяций, которая слагается из физиологического гомеостаза отдельных индивидов. Последующие главы (4, 5, 6) составляют вторую часть книги, содержанием которой являются непосредственно антропологические аспекты популяционной физиологии человека. Наряду с традиционными для физиологической антропологии подходами к изучению возрастной динамики физиологических признаков и соизменчивости разносистемных признаков используется системный анализ, а полученные результаты трактуются с позиции концепции физиологического гомеостаза. Также не в традиционном ключе рассматриваются проблемы генетической детерминации физиологических признаков ("искусственные", равные по численности выборки доноров; корреляции уровней физиологических показателей крови с признаками пигментации). В заключении обсуждается теоретическое и практическое значение работы и намечаются перспективы дальнейших исследований. Заканчивая вводную часть, считаю приятным долгом отметить с особой признательностью помощь и постоянное участие моих ближайших коллег, спутников в полевых исследованиях. В первую очередь выражаю глубочайшую благодарность Татьяне Ивановне Алексеевой. Т.И.Алексеева, впоследствии академик РАН, стояла у истоков отечественных исследований по физиологической антропологии. Под ее руководством я в студенческие годы отправилась в первую антропологическую экспедицию и навсегда полюбила романтику и трудности экспедиционной жизни. Я признательна И.В.Перевозчикову, которому обязана дружескими советами, поддержкой и сотрудничеством, В.В.Волкову-Дубровину, О.М.Павловскому, Н.С.Смирновой, Т.П.Чижиковой, Н.И.Кочетковой, А.М.Мауреру, А.В.Суховой и Е.И.Балахоновой. С благодарностью вспоминаю Елену Николаевну Хрисанфову, заслуженного профессора МГУ, проявлявшую постоянный интерес к моей работе. Эта книга – и дань памяти моим родителям Марии Андреевне и Константину Михайловичу Гудковым. Нельзя не вспомнить с большой теплотой непосредственных участников наших исследований – людей, которые не были равнодушны к нашей работе, помогали нам жить и собирать материал в многочисленных экспедициях. Это обследованные нами люди, это помогавшие нам медицинские сестры, учителя и директора школ, председатели колхозов и бригадиры, руководители райкомов и различных предприятий, гостеприимные жители деревень, поселков и кишлаков: камчадалы, каракалпаки, киргизы, русские, таджики, туркмены, хакасы, чукчи, эскимосы. Книга посвящена людям, благодаря которым появилась популяционная физиология человека; науке, благодаря которой нескончаемы наши исследовательские устремления, и окружающему миру, многообразие и красота которого поражала нас в экспедициях. Summary
Human population physiology (anthropological aspects) Introduction The plentiful information on the variability of different physiological characters in different human populations was in need of a general point of view to explain the differences between them. But the traditional explanations for physiological anthropology could not solve the problem of interpreting the results. In the present work the author has applied the concept of physiological homeostasis for the explanation of the stability and variability of the physiological status of populations. The dependence of physiological homeostasis on the ecological factors is looked upon as the main mechanism, which determines the physiological structure of populations living in different environments and at different stages of the adaptation process. Chapter 1. Human population physiology: history, conceptions and ideas The concept of physiological homeostasis (Cannon, 1932) became the theoretical basis of a new branch of physiological anthropology – human population physiology. Human population physiology investigates the physiological structure of populations in concrete environments. In the evolution process the physiological mechanisms are developed as an answer to the demands of the environment and must be in accordance with those ecological factors in which the organism is living. The active existence of organisms in a variety of situations is determined by homeostasis, which can equalize the environmental temporal and space variability. All types of adaptation are based on the homeostasis mechanism. The violation of homeostasis by environmental factors or a signal of the probability of a violation through the highest regulation levels activates systems, which are responsible for the adaptation. In human population physiology homeostasis, adaptation and ecological factors are looked upon from the population level as a complex of causes and effects. The methodological basis of this branch is the systemic and integral approach. From the point of view of the systemic approach, physiological homeostasis is determined as the ability of the population to preserve the dynamic stability of its physiological status in a changing environment and the physiological status of a population is determined as a totality of physiological variables, which are interdependent on the organism level and are correlated on the population level. If we take into account these definitions the physiological structure of a population may be looked upon as an integral formation, which is ensured by an aggregate of stable connections between the separate parts of the common system. The combination of physiological variables may be different and depends on the aim of the work. The variables in this work – the physiological blood characters – characterize separate metabolic peculiarities of the organism and are engaged in different processes of energy balance. The physiological blood levels are quantitative phenotypic characters, which can change in the limits of the reaction norm. These characters belong to "rigid" constants for which even small changes can be signals for mobilizing homeostatic regulation systems, but their reactivity makes adaptations and the degree of the adaptation of a character may be judged relatively only to other states of this character. An original model that can cast light on the peculiarities of the metabolic processes not seen in usual conditions is the situation of extreme influence, which gives the same results in every biological population and causes the rise of the phenotypic variability based on a genetic-physiological complex of adaptation mechanisms. Thus, human population physiology is a branch of physiological anthropology, which deals: – the study of stability and variability of physiological variables; – the study of physiological status as a system; – the study of intrasystemic and intersystemic correlations; – the study of co-variation in the system population-environment, whose the dynamic the population physiological homeostasis reflects. Chapter 2. Materials and methods The need for comparing very different populations from the ecological point of view determined the choice of the following regions: the temperate zone (Khakassia, Kamchatka), the arctic zone (Chukot), the arid zone (Turkmenia, Karakalpakia, Kazakhstan) and a medium altitude (Kirghizia, Tajikistan). The climatic conditions of the arctic and arid zones are extreme environments. But the climate of the arid zone is considered less extreme than the arctic. The arid climate of Middle Asia is divided into two periods (seasons): from the middle May till the middle of October it is hot and dry; the rest of the year is damp and. Aboriginal residents of the above-mentioned regions, males and females from 20 to 59 years old, children 7–17 years old and blood donors from Moscow were investigated. Because of the climatic peculiarities of the Middle Asia deserts, the Turkmen and Karakalpaks were studied twice – once before the hot season and again in the hot period. The levels of physiological blood characters – hemoglobin, serum proteins (total protein, albumin, alpha1-, alpha2-, beta-, gamma-globulins), serum cholesterol and glucose – were determined by standard spectrophotometer methods. The high variability of physiological blood levels demands strict unification of laboratory and fieldwork. In our case all physiological blood levels were determined by the author and it is very important for correctly calculating the estimates of intragroup and intergroup variability of the physiological status of populations. The estimation of adaptability was done with the approach of systemic analysis, which includes different methods of univariate and multivariate biometrics. Chapter 3. Physiological homeostasis in human populations For the purpose of classifying populations by their physiological status, cluster analysis was carried out. Khakass, Kamchadals and recent migrants to Kamchatka live in the temperate climatic zone and they formed one cluster. In spite of a general similarity, the physiological status of a separate group can have peculiarities. For example, the Kamchatka migrants have relatively low gamma-globulin levels, which is connected with strained immuno-structural homeostasis as a result of insufficient adaptation to a new environment – the "stress of pioneers". Kirgiz, Tajiks, Kazakhs and Turkmen formed a separate cluster. In spite of the fact that two populations represent the aborigines of medium altitude mountains and two represent the arid zone at sea-level the mean values of physiological blood levels are very alike. It seems that they are united in the same cluster by the ecological peculiarities (including cultural and demographic similarities) of the people of Middle Asia and Kazakhstan. From the position of the theory of physiological stability, this result may be estimated for these populations as an adaptive state. But it may appear that this argument is in contradiction with the fact that the populations of Turkmen and Karakalpaks investigated in the hot period, when the situation is classified as extreme, formed an independent cluster. A high air temperature causes variable physiological alterations in the organism in the desert that are aimed at stabilizing the internal temperature balance. Under the influence of the high temperature of the environment the synthesis and resynthesis of proteins is violated: the concentration of albumen, which is connected with water metabolism, becomes higher; the immunology reactions become depressed; the quantity of cholesterol becomes less; and as a compensatory reaction the level of hemoglobin becomes higher, providing a normal supply of oxygen to the tissues. The discriminant analysis indicates that the overlap of two samples out of one population is so small that only 2,5% of Turkmen analysed in the hot period can be diagnosed as belonging to the sample analysed before the hot period. That is why two samples taken from one Turkmen population are in different clusters. In one cluster with Turkmen, which were examined in the hot season, are Karakalpaks, which were examined also in the hot season but at the time of collecting cotton. When this is done, magnesium chlorate is employed and the contact with this defoliant lowers the hemoglobin levels, the protein levels are also changed and the activity of the alkaline phosphates decreases. As a result of the latter, the cholesterol levels reduce. The physiological status of Karakalpaks formed by the time of examination under the integral influence of extreme climatic and negative manmade factors is the reaction of a population in a more unfavourable ecological situation for health than is the case of Turkmen. For example, the high mean hemoglobin level (in the hot period), characteristic for desert inhabitants, was low among Karakalpaks. Repeated examination of hemoglobin levels before the hot season confirmed our assumption that before the defoliation the mean was equal with the Turkmen. The aborigines of Chukot, Eskimos and the Coast Chukchi formed an dependent cluster. The climatic and geographical nature of the arctic zone includes a broad spectrum of extreme ecological factors and it is considered that the main factor is the radiation condition. In the variety of human reactions to the environmental influences of high latitudes, the main role is played by the physiological systems, which are connected with metabolic and energy processes. The union of two aboriginal samples of Chukot on a higher hierarchical level in comparison with other groups is a result of marked differences in their physiological status. The difference between means in all analysed characters of Eskimos and Chukchi is statistically significant. This result is to some extent unexpected, because both populations are in the same ecological environment. The highest difference is in cholesterol levels: the Eskimos have the highest mean on the intragroup scale. The studies of the last years have shown that the high cholesterol levels and low blood pressure is are not a historically dependent phenomena. The cholesterol levels and the percentage of hypercholesterolemia in Eskimos depends on the process of "food acculturation". The main difference in diet lies in the lowering of the habitual fat and protein intake and an unusually large quantity of carbohydrates, which can violate the lipid metabolism of the aboriginal people. The increase of cholesterol levels in north aborigines is also connected with regular alcohol intake, a decline in physical activity; emotional stress provoked by urbanization and so on. Many authors think that hypercholesterolemia often is an answer to external influences and changes in the internal situation of an organism. This physiological character has the most taxonomical value in intragroup analysis. The organism has a definite answer to the changes in the environment, which is acquired during long previous evolution in a variable environment. The population response to different conditions of the environment is the rise of phenotypic variability. In a changing environment the population must have a sufficient hereditary reserve of variability to generate the needed adaptive changes. That is why, when discussing the results of negative influences of different factors on the population, the mean values of physiological characters appear insufficient from the information point of view. The reaction of a population to unfavourable changes of the environment is also expressed in the increase of intergroup variability and the extension of the variability curve. For the estimation of population physiological status dependent on the environment correlation and factor analyses are very informative. When the correlation matrix is analysed from the point of view of the ecological peculiarities of every population, it was found that the relative number of reliable correlations grows in the populations that are in an extreme environment and the most connected traits are those which show maximum reactivity. The canonical correlation also grows in populations in extreme conditions. This phenomenon, as was shown by the studies on the theory of systems, leads to the disintegration of a system with many levels, which in our case marks a violation of the physiological homeostasis of populations. The results of factor analysis of the physiological status are as follows: – factor of integrative regulation; – factor of nutrition; – energy factor; – factor of the immunity. All matrixes (for arid, arctic and temperate zones) in general are very much alike, but for the populations in an extreme environment, they have certain peculiarities. Different methods of studying the variability of the physiological structure of populations gives us an opportunity to establish the difference or similarity between them in their physiological status from the point of view of the ecological peculiarities, adaptation and disadaptation. Temporal unfavourable changes in the environment (for example, the climate periodicity of the arid zone) bring about changes of the population physiological status. But this process is reversible and after the change of the season homeostasis is reestablished and the population returns to the usual state of adaptability. A good test of the limits of human adaptive ability is the quick changes in stress that are connected with modern society, which took place in Chukot. The changing ecological reality – abrupt changes in the way of life in constantly extreme climatic and geographical conditions – affected both Chukot populations, but the reaction of their physiological structure was different. The violation of physiological homeostasis and a number of medical and sociological characteristics indicate a lowering of the Eskimos' adaptivness to the environment. To the extreme Arctic environment the Eskimos adapted for several thousand years. In modern conditions the aborigines of the North are forced to adapt to a new heterogeneous environment, which is quite different from that in which most of their natural history took place. Keeping in mind the R.Fisher model of adaptation to an undirected worsening of the environment, one can propose that populations more specialized and with restricted homeostatic possibilities cannot endure substantial changes in the environment. Evidently the Eskimos are a highly specialized group the adaptive possibilities of which have expired. That is why we can conclude that the Eskimo population is in a state of disadaptation. For the Coast Chukchi, as a "younger" population comparable with Eskimos, the prognosis is more optimistic. Chapter 4. Physiological status in ontogenesis In spite of small numbers in each age group, thanks to the systemic analysis, we got new information about the age variability of physiological characters among children. No doubt it was also the result of the complex nature of the investigation. It is established, that characteristic changes of physiological status of children and teenagers occur in certain age periods, which are connected with processes of growth and development and which influence physiological homeostasis. Substational changes in the levels of physiological blood characters are more marked in boys and coincide with the time of puberty. The activation of internal physiological processes is the first in the general age changes. Different sensitivity of physiological and morphological systems to an effect of various factors is the cause of the failure to coincide between the rates of variability of traits of different systems. At the end of the puberties changes the typical values of physiological and morphological correlations are established. In definite age periods the intragroup variability of physiological blood levels rises that evidences of the strain of physiological homeostasis in the reforming organism. There is much evidence that the age dynamics of the means of physiological blood characters among adults has some similarities. Today, from the point of view of human population physiology, the analysis of variability of separate physiological characters as an end in itself is not actual, because the population factors operate not on separate characters but on their complexes. It is established, that the age dynamics of the physiological status depends on the ecological situation. The age variability of the means for separate characters and for the physiological status as a hole is more marked in samples from populations of the temperate zone. In samples from populations living in ecological unfavourable conditions the age variability of the means is less. Evidently, the environment stress, which violates the physiological homeostasis, can change also the ontogenetic dynamics on the population level. The rise of variability (the variation coefficents) with age leads to a conclusion, that the physiological homeostasis of separate individuals undergoes the strain (especially severe in ecological unfavourable conditions), which on the population level violates the adaptability of the system for a stable existence in a concrete environment. Every development goes through unstable stages, but a steady rise of the averaged indexes of variability in males of the arctic zone is one more argument in evidence of their disadaptation. Chapter 5. Physiological homeostasis and the constitutional problems Analysis of co-variation of morphological and physiological characters is important in resolving the problem of biological integrity. More than a hundred years of investigation morphophysiological correlations did not lead to understanding of the causes for divergence in results in different populations. The author has suggested a new concept for this phenomenon that is based on the idea of population physiological homeostasis that depends on ecological factors. Analysis of co-variation of morphological and physiological characters showed that there are several stable correlations in most populations. There is also sex dimorphism of co-variation in different systems of characters. Several correlations had a clear adaptive explanation. The variability of the correlation coefficients depends on the state of population physiological homeostasis, which can change the degree and the direction of the correlations. Factor analysis of the morphophysiological system of variables reflected the very important role (men of the arctic zone) of metabolic reactions and there influence on the morphological status of populations. This result essentially broadens our presentations of adaptation as a gradual stage adaptive biological process. With the help of discriminant analysis was made a comparison between somatotypes of individuals and their physiological and morphological characters. The result was that the morphological traits were better predictors of a somatotype, but the combined prediction by both sets of characters gave the highest percent of a somatotype status. The differences of discriminant analysis results depends on violations of physiological homeostasis of populations which are in extremal ecological conditions. Chapter 6. On the question of heredity of physiological characteristics The levels of physiological blood characters were determined in four equal donor samples (50 persons each) who had different phenotypes of ABO blood group system. This method of sampling was specially made to get a statistically representative number of the AB phenotype. The results of discriminant analysis gave a statistically significant differences between the physiological status of AB phenotype and the physiological status of A and B phenotypes. Intergroup variability of physiological variables (with some exceptions) in AB phenotypes part of the sample of donors was low. This interesting fact may be looked upon as the lowering of the environment dispersion in heterozygotes. It was established, that there is a connection between the levels of physiological blood characters and pigmentation. The research in this direction must be continued because it may throw more light on the processes of microdifferentiation of modern human populations. Conclusion A close evolutionary relationship of physiology and ecology of organisms determines the dynamic dependence of the population physiological status in man on ecological factors. For the explanation of the stability and variability of population physiological status the concept of physiological homeostasis was applied. The investigation of physiological status in several populations of Middle Asia, Kazakhstan, North-East Asia and Khakassia has shown that reversible changes in the environment may temporarily destabilize the equilibrium in the "population-environment" system and prolonged stresses may cause a state of disadaptation. For estimation of population physiological homeostasis dependent on the environment the values of variability, correlation and factor analyses are very informative. They not only mark the violation of population homeostasis, but also indicate changes in the environment. Thus, the variability of the population physiological homeostasis reflects changes in the environment. That is why the population physiological homeostasis stability may be looked at in the context of a "stable society" as a deposit of population viability and its harmony with the inviolable environment. Опечатка
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