“Data for the problem of evolution in man. A first study of the inheritance of longevity and the selective death-rate in man”

1900 ◽  
Vol 35 (2) ◽  
pp. 112-129 ◽  
Author(s):  
Mary Beeton ◽  
Karl Pearson
Keyword(s):  
Natural Selection ◽  
Life Insurance ◽  
Death Rate ◽  
Quantitative Measure ◽  
Commercial Importance ◽  
Biological Interest ◽  
Selective Death

According to Wallace and Weisman the duration of life in any organism is determined by natural selection. An organism lives so long as it is advantageous, not to itself, but to its species, that it should live. But it would be impossible for natural selection to determine the fit duration of life, as it would be impossible for it to fix any other character, unless that character were inherited. Accordingly the hypothesis above referred to supposes that duration of life is an inherited character. So far as we are aware, however, neither of the above-mentioned naturalists, nor any other investigators, have published researches bearing on the problem of whether duration of life is or is not inherited. We are accustomed to hear of a particular man that “he comes of a long-lived family”, but the quantitative measure of the inheritance of life's duration does not yet seem to have been determined. This absence of investigation appears the more remarkable as a knowledge of the magnitude of inheritance in this respect would, we should conceive, be of primary commercial importance in the consideration of life insurance and of annuities. The biological interest of the problem, as we have already noticed, is very great.

scholarly journals The intensity of natural selection in man

1912 ◽  
Vol 85 (581) ◽  
pp. 469-476 ◽  
Keyword(s):  
Natural Selection ◽  
Death Rate ◽  
Age Groups ◽  
First Year ◽  
Human Beings ◽  
High Infant Mortality ◽  
Total Death ◽  
Selective Death ◽  
First Year Of Life ◽  
Varying Environment

(1) In a paper communicated to the Royal Society in 1899, and later in greater elaboration published in ‘Biometrika,’ 1901, it has been shown on the basis of the inheritance of longevity that the selective death-rate in man amounted to at least 60 per cent. to 80 per cent. of the total death-rate. The matter has been recently reconsidered by Prof. Ploetz, who, dealing with material wholly different from that of Beeton and Pearson came to similar conclusions. The point is a very vital one, for, combined with: (i) the heredity of physical and mental characters in man, and (ii) the demonstration that the longer-lived have more offspring, we reach a definite knowledge that Darwinism does apply, and very intensely applies, even to man under civilised conditions. The difficulty of a direct investigation of the problem lies in securing uniformity of environment. W e have to demonstrate that when under the same environment there is a heavier death-rate among a given group of human beings, then among the survivors of this group in a given later period the death-rate will be lessened. Now each group of individuals we attempt to deal with has its own environment, and if that is a bad environment we should expect to find a heavy death-rate both at the earlier and later periods; this obviously must obscure the action of natural selection. For example in districts with a high infant mortality we might expect a high child mortality, say deaths from two to five years of life, because a bad environment sends up the intensity of both. The correlation between deaths in the first year of life (0—1) and in the next four years of life (1—5) for a given district will certainly be positive if no correction be made for varying environment. Quite recently this matter has been discussed by determining the correlation between the ages 0—1 and 1—5 in the administrative counties of England and Wales. As ( a ) the group 0—1 was not followed to 1—5, but the deaths in these age-groups for the same years were dealt with, and ( b ) no allowance whatever was made for the differential environment of the administrative counties, it is difficult to find any real bearing of the data on the problem of natural selection in man.

Data for the problem of evolution in man. II. A first study of the inheritance of longevity and the selective death-rate in man

1900 ◽  
Vol 65 (413-422) ◽  
pp. 290-305 ◽  
Keyword(s):  
Natural Selection ◽  
Death Rate ◽  
Selective Death

1. According to Wallace and Weismann the duration of life in any organism is determined by natural selection. An organism lives so long as it is advantageous, not to itself, but to its species, that it should live.

scholarly journals A discussion on the present state of theory of natural selection

1936 ◽  
Vol 121 (820) ◽  
pp. 43-73 ◽  
Keyword(s):  
Natural Selection ◽  
Present State ◽  
Death Rate ◽  
Origin Of Species ◽  
Selective Death

“ Natural selection or the preservation of favoured races in the struggle for life ” is an explanation primarily of adaptation and only secondarily of the origin of species. It rests on the assumption that the differences between individual members of a species which live together in the same district are heritable, and that they may determine the life or death of the individuals in question at an earlier or later time than one another. In other words, that definite variation in structure or in function may be responsible for a selective death-rate.

scholarly journals Abridged Life Tables of Pakistan and Provinces by Sex, 1962

1967 ◽  
Vol 7 (1) ◽  
pp. 66-106 ◽  
Author(s):  
Muhammad Aslam ◽  
Sultan S. Hashmi ◽  
William Seltzer
Keyword(s):  
Life Table ◽  
Life Insurance ◽  
Death Rate ◽  
Average Duration ◽  
Life Tables ◽  
Infant Mortality Rate ◽  
Crude Death Rate ◽  
Comprehensive Method ◽  
Demographic Indices ◽  
Different Populations

Mortality in a population is measured by a number of demographic indices such as the crude death rate, the infant mortality rate, the age-specific death rate or the standardised death rate. Still another more comprehensive method of portraying mortality conditions in a population is by means of a life table. A life table as compared to other mortality indices serves many useful purposes. For measuring longevity of life, projecting current population into the future or estimating incidence of widowhood and orphanhood, a life table is essential. For comparison of expectation of life (or average duration of life) at birth and after birth for various ages of different populations the life table is also commonly used. Besides its utility in demographic problems, still another important use of a life table is made by actuaries in life insurance. The life table is also becoming an important tool of investigation for problems of commerce and industry as it enables one to describe the expectation of life of many nonhuman populations. For detailed discussion of various kinds of life tables and their uses, the reader is advised to refer to any one of many standard reference works [6, Chapters 12 and 13].

scholarly journals Studies in the Meaning and Relationships of Birth and Death Rates. II. Density of Population and Death Rate (Farr's Law)

1915 ◽  
Vol 15 (1) ◽  
pp. 11-16 ◽  
Author(s):  
John Brownlee
Keyword(s):  
Death Rate ◽  
Quantitative Measure ◽  
Vital Statistics ◽  
Death Rates ◽  
The Real ◽  
Complete Neglect ◽  
The Law

This subject was first considered statistically by the late Dr Farr. It is one of the brilliant attempts to extract the real meaning of figures so frequent in his work, but though this theory has not shared in the complete neglect that has been the lot of his attempt to put a quantitative measure to the course of epidemics, it has suffered as much from the kind of patronage with which it is usually discussed. On at least one of the great medical officers of health of his time, however,— the late Dr J. B. Russell—the theory exercised a strong fascination. My own copy of Fare's Vital Statistics came from Dr Russell's library, and the whole passage referring to the law is lined with his characteristic nervous pencil marks, while in much of his work on vital statistics the influence can easily be traced.

On the method of comparing the Expected with the Actual Experience of a Life Insurance Company, as regards the number of Deaths and amount of Claims

1874 ◽  
Vol 18 (3) ◽  
pp. 195-211
Author(s):  
George M. Low
Keyword(s):  
General Population ◽  
Life Insurance ◽  
Death Rate ◽  
Insurance Company ◽  
Life Insurance Company ◽  
Life Assurance ◽  
Actual Experience ◽  
Mortality Table ◽  
To Receive

The business of Life Assurance is founded on the principle that the number of deaths which will occur among a large number of persons in a given time is not a matter dependent entirely on what is called chance; but is subject to a law of average so uniform in its operations, and so trustworthy as to its results, as to be capable of forming the basis of calculations on which the shareholder may stake his capital, and the assured the welfare of those for whom it is his duty to provide. Proceeding on this principle, tables of mortality have been constructed,—from data collected at different places and under a variety of circumstances, and tabulated and adjusted with various degrees of accuracy,—which show, out of a given number of persons born, the number who survive each year of age, and the number who die at each age from year to year. From such tables, companies transacting the business of assurance calculate the rates of contribution to be required from their clients; and on the sufficiency of the rate of mortality founded on in any instance depends, of course, the sufficiency of the premiums which the company is to receive in consideration of its risks. It is therefore of great consequence that the company should ascertain from time to time how the rate of mortality actually experienced compares with that indicated by the table on which the calculations are founded, in order that there may be proper grounds for being satisfied that the basis is a correct one. For it is not sufficient that the mortality table founded on should be known to represent faithfully the death-rate prevailing among the general population, or even among assured lives generally.

scholarly journals On the ancestral gametic correlations of a mendelian population mating at random

1909 ◽  
Vol 81 (547) ◽  
pp. 225-229 ◽  
Keyword(s):  
Death Rate ◽  
First Principle ◽  
Differential Fertility ◽  
Mendelian Population ◽  
Geometrical Progression ◽  
Gametic Constitution ◽  
Mendelian Character ◽  
The Law ◽  
Selective Death ◽  
P 53

(1) The population to be considered in this paper is supposed to be initated by a group of s 1 individuals with the protogenic constitution ( aa ), and s 3 individuals with the hydrid constitution (A a ), where the mating is given by the simple Mendelian formula: (AA) X ( aa ) = 4 (A a ). I do not assume at this stage any relation between the gametic constitution of an individual and its somatic character. I propose first to consider the correlation between any ancestor and the resulting array of offspring, when we regard only their gametic constitutions. I assume that all mating in the population is random, i. e . That every possible mating occurs simply in the population, and that there is no differential fertility or selective death-rate. In a paper published in the “Phil. Trans.,’ vol. 203, A, 1904, P. 53 et seq ., I have dealt with the correlation between the somatic characters of the ancestry and the offspring in an population of a Mendelian character, more general in that I supposed the character to depend upon n couplets, and not a single Mendelian couplet, less general in that I supposed the population to have arisen from a series of initial hybridisations, and not form a mixture as in the present case of hybrids and numbers of two pure races in any proportions. In that paper I showed ( a ) that there was correlation between any ancestor and the offspring, ( b ) that the regression for any ancestor and the offspring was linear, and ( c ) that the correlations decreased in geometrical progression. These are the chief characteristics of the Law of Ancestral Heredity. It was clear that, judged by somatic characters only. Ancestry was of importance. The result depended on Mendel’s first principle of dominance being absolutely true. The values of the correlations were, how ever, less than those with which biometric work had made us familiar.

scholarly journals The magnitude of innovation and its evolution in social animals

2017 ◽  
Vol 284 (1848) ◽  
pp. 20162385 ◽  
Author(s):  
Michal Arbilly ◽  
Kevin N. Laland
Keyword(s):  
Natural Selection ◽  
Social Interaction ◽  
Mathematical Modelling ◽  
Computer Simulations ◽  
Quantitative Measure ◽  
Broad Definition ◽  
High Magnitude ◽  
Social Animals ◽  
Innovative Behaviour ◽  
Social Rewards

Innovative behaviour in animals, ranging from invertebrates to humans, is increasingly recognized as an important topic for investigation by behavioural researchers. However, what constitutes an innovation remains controversial, and difficult to quantify. Drawing on a broad definition whereby any behaviour with a new component to it is an innovation, we propose a quantitative measure, which we call the magnitude of innovation , to describe the extent to which an innovative behaviour is novel. This allows us to distinguish between innovations that are a slight change to existing behaviours (low magnitude), and innovations that are substantially different (high magnitude). Using mathematical modelling and evolutionary computer simulations, we explored how aspects of social interaction, cognition and natural selection affect the frequency and magnitude of innovation. We show that high-magnitude innovations are likely to arise regularly even if the frequency of innovation is low, as long as this frequency is relatively constant, and that the selectivity of social learning and the existence of social rewards, such as prestige and royalties, are crucial for innovative behaviour to evolve. We suggest that consideration of the magnitude of innovation may prove a useful tool in the study of the evolution of cognition and of culture.

Sign in / Sign up

Export Citation Format

Share Document