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  1. Article ; Online: Twinning in humans: maternal heterogeneity in reproduction and survival.

    Robson, Shannen L / Smith, Ken R

    Proceedings. Biological sciences

    2011  Volume 278, Issue 1725, Page(s) 3755–3761

    Abstract: While humans usually give birth to singletons, dizygotic twinning occurs at low rates in all populations worldwide. We evaluate two hypotheses that have differing expectations about the effects of bearing twins on maternal lifetime reproduction and ... ...

    Abstract While humans usually give birth to singletons, dizygotic twinning occurs at low rates in all populations worldwide. We evaluate two hypotheses that have differing expectations about the effects of bearing twins on maternal lifetime reproduction and survival. The maternal depletion hypothesis argues that mothers of twins will suffer negative outcomes owing to the higher physiological costs associated with bearing multiples. Alternatively, twinning, while costly, may indicate mothers with a greater capacity to bear that cost. Drawing from the vast natural fertility data in the Utah Population Database, we compared the reproductive and survival events of 4603 mothers who bore twins and 54 183 who had not. These mothers were born between 1807 and 1899, lived at least to the age of 50 years and married once to men who were alive when their wives were 50. Results from proportional hazards and regression analyses are consistent with the second hypothesis. Mothers of twins exhibit lower postmenopausal mortality, shorter average inter-birth intervals, later ages at last birth and higher lifetime fertility than their singleton-only bearing counterparts. From the largest historical sample of twinning mothers yet published, we conclude that bearing twins is more likely for those with a robust phenotype and is a useful index of maternal heterogeneity.
    MeSH term(s) Adult ; Birth Intervals ; Female ; Fertility ; Humans ; Linear Models ; Maternal Age ; Mortality ; Parity ; Phenotype ; Postmenopause ; Pregnancy ; Pregnancy, Multiple/physiology ; Pregnancy, Multiple/statistics & numerical data ; Utah
    Language English
    Publishing date 2011-05-11
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 209242-6
    ISSN 1471-2954 ; 0080-4649 ; 0962-8452 ; 0950-1193
    ISSN (online) 1471-2954
    ISSN 0080-4649 ; 0962-8452 ; 0950-1193
    DOI 10.1098/rspb.2011.05
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 1364: Show issues Location:
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  2. Article: First Record of Sorex tenellus from Utah

    Rickart, Eric A / Duke S. Rogers / Lois F. Alexander / Shannen L. Robson

    Western North American naturalist. 2017 Dec., v. 77, no. 4

    2017  

    Abstract: A specimen of the Inyo shrew, Sorex tenellus, was collected in piñon-juniper woodland at 2017 m elevation in Granite Creek Canyon, Deep Creek Range, Juab Co., Utah. This is the easternmost record for this species and the first record for Utah. ...

    Abstract A specimen of the Inyo shrew, Sorex tenellus, was collected in piñon-juniper woodland at 2017 m elevation in Granite Creek Canyon, Deep Creek Range, Juab Co., Utah. This is the easternmost record for this species and the first record for Utah.
    Keywords shrews ; Sorex ; streams ; woodlands ; Utah
    Language English
    Dates of publication 2017-12
    Size p. 545-548.
    Publishing place Brigham Young University
    Document type Article
    ZDB-ID 2486542-4
    ISSN 1944-8341 ; 1527-0904
    ISSN (online) 1944-8341
    ISSN 1527-0904
    DOI 10.3398/064.077.0401
    Database NAL-Catalogue (AGRICOLA)

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  3. Article: Breast milk, diet, and large human brains

    Robson, Shannen L

    Current anthropology Vol. 45, No. 3 , p. 419-425

    2004  Volume 45, Issue 3, Page(s) 419–425

    Author's details Shannen L. Robson
    Language English
    Size graph. Darst.
    Publisher Univ. of Chicago Press
    Publishing place Chicago, Ill
    Document type Article
    Database Former special subject collection: coastal and deep sea fishing

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  4. Article ; Online: Hominin life history: reconstruction and evolution.

    Robson, Shannen L / Wood, Bernard

    Journal of anatomy

    2008  Volume 212, Issue 4, Page(s) 394–425

    Abstract: In this review we attempt to reconstruct the evolutionary history of hominin life history from extant and fossil evidence. We utilize demographic life history theory and distinguish life history variables, traits such as weaning, age at sexual maturity, ... ...

    Abstract In this review we attempt to reconstruct the evolutionary history of hominin life history from extant and fossil evidence. We utilize demographic life history theory and distinguish life history variables, traits such as weaning, age at sexual maturity, and life span, from life history-related variables such as body mass, brain growth, and dental development. The latter are either linked with, or can be used to make inferences about, life history, thus providing an opportunity for estimating life history parameters in fossil taxa. We compare the life history variables of modern great apes and identify traits that are likely to be shared by the last common ancestor of Pan-Homo and those likely to be derived in hominins. All great apes exhibit slow life histories and we infer this to be true of the last common ancestor of Pan-Homo and the stem hominin. Modern human life histories are even slower, exhibiting distinctively long post-menopausal life spans and later ages at maturity, pointing to a reduction in adult mortality since the Pan-Homo split. We suggest that lower adult mortality, distinctively short interbirth intervals, and early weaning characteristic of modern humans are derived features resulting from cooperative breeding. We evaluate the fidelity of three life history-related variables, body mass, brain growth and dental development, with the life history parameters of living great apes. We found that body mass is the best predictor of great ape life history events. Brain growth trajectories and dental development and eruption are weakly related proxies and inferences from them should be made with caution. We evaluate the evidence of life history-related variables available for extinct species and find that prior to the transitional hominins there is no evidence of any hominin taxon possessing a body size, brain size or aspects of dental development much different from what we assume to be the primitive life history pattern for the Pan-Homo clade. Data for life history-related variables among the transitional hominin grade are consistent and none agrees with a modern human pattern. Aside from mean body mass, adult brain size, crown and root formation times, and the timing and sequence of dental eruption of Homo erectus are inconsistent with that of modern humans. Homo antecessor fossil material suggests a brain size similar to that of Homo erectus s. s., and crown formation times that are not yet modern, though there is some evidence of modern human-like timing of tooth formation and eruption. The body sizes, brain sizes, and dental development of Homo heidelbergensis and Homo neanderthalensis are consistent with a modern human life history but samples are too small to be certain that they have life histories within the modern human range. As more life history-related variable information for hominin species accumulates we are discovering that they can also have distinctive life histories that do not conform to any living model. At least one extinct hominin subclade, Paranthropus, has a pattern of dental life history-related variables that most likely set it apart from the life histories of both modern humans and chimpanzees.
    MeSH term(s) Animals ; Anthropology, Physical ; Biological Evolution ; Brain/physiology ; Dentition ; Hominidae/physiology ; Life Cycle Stages ; Reproduction/physiology
    Language English
    Publishing date 2008-04-14
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 2955-5
    ISSN 1469-7580 ; 0021-8782
    ISSN (online) 1469-7580
    ISSN 0021-8782
    DOI 10.1111/j.1469-7580.2008.00867.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Ub I Zs.38: Show issues Location:
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  5. Article: Twinning in humans: maternal heterogeneity in reproduction and survival

    Robson, Shannen L / Smith, Ken R

    Proceedings. Biological sciences. 2011 Dec. 22, v. 278, no. 1725

    2011  

    Abstract: While humans usually give birth to singletons, dizygotic twinning occurs at low rates in all populations worldwide. We evaluate two hypotheses that have differing expectations about the effects of bearing twins on maternal lifetime reproduction and ... ...

    Abstract While humans usually give birth to singletons, dizygotic twinning occurs at low rates in all populations worldwide. We evaluate two hypotheses that have differing expectations about the effects of bearing twins on maternal lifetime reproduction and survival. The maternal depletion hypothesis argues that mothers of twins will suffer negative outcomes owing to the higher physiological costs associated with bearing multiples. Alternatively, twinning, while costly, may indicate mothers with a greater capacity to bear that cost. Drawing from the vast natural fertility data in the Utah Population Database, we compared the reproductive and survival events of 4603 mothers who bore twins and 54 183 who had not. These mothers were born between 1807 and 1899, lived at least to the age of 50 years and married once to men who were alive when their wives were 50. Results from proportional hazards and regression analyses are consistent with the second hypothesis. Mothers of twins exhibit lower postmenopausal mortality, shorter average inter-birth intervals, later ages at last birth and higher lifetime fertility than their singleton-only bearing counterparts. From the largest historical sample of twinning mothers yet published, we conclude that bearing twins is more likely for those with a robust phenotype and is a useful index of maternal heterogeneity.
    Keywords databases ; humans ; men ; mortality ; mothers ; phenotype ; postmenopause ; regression analysis ; twins ; Utah
    Language English
    Dates of publication 2011-1222
    Size p. 3755-3761.
    Publishing place Royal Society
    Document type Article
    ZDB-ID 209242-6
    ISSN 1471-2954 ; 0080-4649 ; 0962-8452 ; 0950-1193
    ISSN (online) 1471-2954
    ISSN 0080-4649 ; 0962-8452 ; 0950-1193
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Bonn / Germany

    Z 46/95: Show issues

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  6. Article ; Online: Mortality and fertility rates in humans and chimpanzees: How within-species variation complicates cross-species comparisons.

    Hawkes, Kristen / Smith, Ken R / Robson, Shannen L

    American journal of human biology : the official journal of the Human Biology Council

    2009  Volume 21, Issue 4, Page(s) 578–586

    Abstract: A grandmother hypothesis may explain why humans evolved greater longevity while continuing to end female fertility at about the same age as do the other great apes. With that grandmother hypothesis in mind, we sought to compare age-specific mortality and ...

    Abstract A grandmother hypothesis may explain why humans evolved greater longevity while continuing to end female fertility at about the same age as do the other great apes. With that grandmother hypothesis in mind, we sought to compare age-specific mortality and fertility rates between humans and chimpanzees, our closest living relatives, and found two puzzles. First, we expected that lower adult mortality in humans would be associated with slower senescence, but the rate of chimpanzee demographic aging falls within the human range. Second, we expected declines in age-specific fertility to be similar in the two species but instead of falling in the thirties as it does in women, fertility remains high into the forties in some chimpanzee populations. We report these puzzles using data from nine human populations and both wild and captive chimpanzees, and suggest that systematic differences in the heterogeneity of surviving adults may explain them.
    MeSH term(s) Adult ; Age Factors ; Aged ; Aged, 80 and over ; Animals ; Biological Evolution ; Female ; Fertility/physiology ; Humans ; Middle Aged ; Models, Biological ; Mortality ; Pan troglodytes/physiology ; Species Specificity
    Language English
    Publishing date 2009-02-26
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1025339-7
    ISSN 1520-6300 ; 1042-0533
    ISSN (online) 1520-6300
    ISSN 1042-0533
    DOI 10.1002/ajhb.20890
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2567: Show issues Location:
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