Found 2106 Hypotheses across 211 Pages (0.007 seconds)
  1. There is less phenotypic diversity of the female birth canal with greater distance from sub-Saharan Africa.Betti, Lia - Human variation in the shape of the birth canal is significant and geographi..., 2018 - 2 Variables

    The 'obstetrical dilemma' postulates that human females evolved a pelvis shape that was a compromise between the needs of bipedal locomotion and the need for a wider pelvic opening. The implication is that the female pelvis should be similar across the world. Researchers examine the size and shape of the birth canal of female individuals in the Goldman and Human Origin datasets. Contrary to the 'obstetrical dilemma,' the findings reveal that there is indeed significant geographical variation in size and shape of the female birth canal. Neutral evolutionary processes, particularly genetic drift, were suggested to be influential in female canal shape whereas the predicted effects of climate on canal diversity were only minimal.

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  2. Smaller females will have a larger than expected birth canal.Betti, Lia - Human variation in the shape of the birth canal is significant and geographi..., 2018 - 2 Variables

    The 'obstetrical dilemma' postulates that human females evolved a pelvis shape that was a compromise between the needs of bipedal locomotion and the need for a wider pelvic opening. The implication is that the female pelvis should be similar across the world. Researchers examine the size and shape of the birth canal of female individuals in the Goldman and Human Origin datasets. Contrary to the 'obstetrical dilemma,' the findings reveal that there is indeed significant geographical variation in size and shape of the female birth canal. Neutral evolutionary processes, particularly genetic drift, were suggested to be influential in female canal shape whereas the predicted effects of climate on canal diversity were only minimal.

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  3. Contrary to the 'obstetrical dilemma,' there will be geographical variation in the shape of the female birth canal.Betti, Lia - Human variation in the shape of the birth canal is significant and geographi..., 2018 - 2 Variables

    The 'obstetrical dilemma' postulates that human females evolved a pelvis shape that was a compromise between the needs of bipedal locomotion and the need for a wider pelvic opening. The implication is that the female pelvis should be similar across the world. Researchers examine the size and shape of the birth canal of female individuals in the Goldman and Human Origin datasets. Contrary to the 'obstetrical dilemma,' the findings reveal that there is indeed significant geographical variation in size and shape of the female birth canal. Neutral evolutionary processes, particularly genetic drift, were suggested to be influential in female canal shape whereas the predicted effects of climate on canal diversity were only minimal.

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  4. There will be a relationship between overall canal shape differences and temperature differences.Betti, Lia - Human variation in the shape of the birth canal is significant and geographi..., 2018 - 2 Variables

    The 'obstetrical dilemma' postulates that human females evolved a pelvis shape that was a compromise between the needs of bipedal locomotion and the need for a wider pelvic opening. The implication is that the female pelvis should be similar across the world. Researchers examine the size and shape of the birth canal of female individuals in the Goldman and Human Origin datasets. Contrary to the 'obstetrical dilemma,' the findings reveal that there is indeed significant geographical variation in size and shape of the female birth canal. Neutral evolutionary processes, particularly genetic drift, were suggested to be influential in female canal shape whereas the predicted effects of climate on canal diversity were only minimal.

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  5. Global mandibular morphological variation will be associated with geographic distance (19546).von Cramon-Taubadel, Noreen - Global human mandibular variation reflects differences in agricultural and h..., 2011 - 2 Variables

    The researchers test the relationship between global mandibular morphology variation and susbsistence economy, population history, geography, and climate. While some mandibular variation is significantly correlated with geography, the most significant relationship is with subsistence activity. The strength of the relationship leads the authors to speculate on how masticatory behavior might have affected jaw shape, either through stress, weaning behavior, or other demographic factors.

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  6. Populations which have remained near their origin will show a lower proportion of long alleles of DRD4 than those that migrated further away (312).Chen, Chuansheng - Population migration and the variation of dopamine D4 receptor (DRD4) allele..., 1999 - 2 Variables

    Dopamine receptor D4 (DRD4) exhibits the largest number of polymorphisms of any dopamine receptor yet identified, and variation in DRD4 has been linked to variation in traits such as novelty-seeking and attention deficit/hyperactivity disorder. DRD4 also exhibits large variation between populations. Here, the authors test the hypothesis that natural selection acting on DRD4 may account for variation in between-population migratory patterns, using genetic and historical data from 39 populations.

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  7. Population level variation in DRD4 alleles is attributable to general bottleneck effects that also acted on non-DRD4 genes (317).Chen, Chuansheng - Population migration and the variation of dopamine D4 receptor (DRD4) allele..., 1999 - 2 Variables

    Dopamine receptor D4 (DRD4) exhibits the largest number of polymorphisms of any dopamine receptor yet identified, and variation in DRD4 has been linked to variation in traits such as novelty-seeking and attention deficit/hyperactivity disorder. DRD4 also exhibits large variation between populations. Here, the authors test the hypothesis that natural selection acting on DRD4 may account for variation in between-population migratory patterns, using genetic and historical data from 39 populations.

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  8. The global pattern of mandibular morphology variation will be associated with dichotomized (hunter/gatherer vs. agricultural/pastoralist) subsistence type (19546).von Cramon-Taubadel, Noreen - Global human mandibular variation reflects differences in agricultural and h..., 2011 - 2 Variables

    The researchers test the relationship between global mandibular morphology variation and susbsistence economy, population history, geography, and climate. While some mandibular variation is significantly correlated with geography, the most significant relationship is with subsistence activity. The strength of the relationship leads the authors to speculate on how masticatory behavior might have affected jaw shape, either through stress, weaning behavior, or other demographic factors.

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  9. The degree of sexual dimorphism of stature will be associated with the degree of polygyny in human societies (434).Alexander, Richard D. - Sexual dimorphisms and breeding systems in pinnipeds, ungulates, primates, a..., 1979 - 2 Variables

    This study examines the relationship between sexual dimorphism and degree of polygyny. Authors test this relationship in both humans and non-human species. In non-human species, every correlation between sexual dimorphism (measured by body length) and degree of polygyny was significant. In human populations, sexual dimporhism was not related to degree of polygyny, however, there were some differences between populations with socially imposed monogomy and those with ecologically imposed monogamy.

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  10. Migratory distance from East Africa will be positively associated with between-population DRD4 exon III expected heterozygosity (2).Gören, Erkan - The biogeographic origins of novelty-seeking traits, 2016 - 2 Variables

    The researcher looks for empirical evidence of natural selection as an explanation for worldwide variation in novelty-seeking behavior. Examining the relationship between variability in frequency of the DRD4 exon III 7-repeat allele variant (a variant theorized to stifle dopamine reception and thus encourage compensatory novelty-seeking behavior) and migratory distance from prehistoric humans' origin point in East Africa yields a positive correlation. After controlling for various biogeographic indicators, the researcher theorizes that presence of the DRD4 exon III 7-repeat variant provided an exploratory urge and evolutionary advantage to hunter-gatherers and pastoralists who migrated into unfamiliar environments.

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