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You searched for subject:(ecogeographic variation). Showing records 1 – 3 of 3 total matches.

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University of Tennessee – Knoxville

1. Savell, Kristen Renée. POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY.

Degree: 2018, University of Tennessee – Knoxville

Human postcranial morphology varies with climate and geography (ecogeography), a pattern that has long been associated with thermoregulatory adaptation. The thermoregulatory imperative model of postcranial evolution suggests that groups living in colder climates have evolved stouter bodies to reduce their surface area/volume ratio, while the opposite is true for groups in the tropics. Recent applications of quantitative genetics methods to human postcranial evolution have allowed researchers to move beyond testing whether limb lengths and measures of body size adhere to ecogeographic expectations, and begin disentangling the natural selection from neutral evolutionary processes.However, these have continued to model postcranial traits as if they were evolving independently. By examining human evolution on a trait-by-trait basis, researchers fail to account for evolution due to changes in correlated morphology. In addition, while these studies are able to identify the direction and magnitude of selective effects, they have yet to identify the source of that selective pressure, often relying on latitude as a problematic proxy for “climate.” In this dissertation, I use quantitative genetic methods to elucidate the role of trait covariation in the evolution of the human postcranium, as well as explore the variables that drive directional selection. Using a large, globally-dispersed sample of human skeletal material, in addition to microsatellite and temperature data, I estimate the selection gradients driving among-group differentiation, compare indices of evolvability across regions, and examine the environmental variables influencing postcranial evolution.Results indicate that 1. trait covariation plays an important role in shaping evolutionary response, 2. human groups may demonstrate emergent differentiation in evolvability across regions , and 3. the selective pressures acting on the postcranium are likely synergistic, complicating simplistic interpretations of the thermoregulatory imperative model. These findings have implications for our understanding of modern human variation, suggesting the need to develop multivariate models in which the reciprocal effects of multiple environmental variables can be examined on the covariance structure of multiple traits. Results also add to the growing evidence that population-specific trait covariance prevents evolutionary interpretations founded on modern humans to be meaningfully translated to ancient hominin lineages.

Subjects/Keywords: natural selection; ecogeographic variation; Bergmann's rule; Allen's rule; evolutionary constraints

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APA (6th Edition):

Savell, K. R. (2018). POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY. (Doctoral Dissertation). University of Tennessee – Knoxville. Retrieved from https://trace.tennessee.edu/utk_graddiss/5071

Chicago Manual of Style (16th Edition):

Savell, Kristen Renée. “POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY.” 2018. Doctoral Dissertation, University of Tennessee – Knoxville. Accessed December 10, 2019. https://trace.tennessee.edu/utk_graddiss/5071.

MLA Handbook (7th Edition):

Savell, Kristen Renée. “POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY.” 2018. Web. 10 Dec 2019.

Vancouver:

Savell KR. POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY. [Internet] [Doctoral dissertation]. University of Tennessee – Knoxville; 2018. [cited 2019 Dec 10]. Available from: https://trace.tennessee.edu/utk_graddiss/5071.

Council of Science Editors:

Savell KR. POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY. [Doctoral Dissertation]. University of Tennessee – Knoxville; 2018. Available from: https://trace.tennessee.edu/utk_graddiss/5071


The Ohio State University

2. Temple, Daniel Howard. Human biological variation during the agricultural transition in prehistoric Japan.

Degree: PhD, Anthropology, 2007, The Ohio State University

This dissertation reconstructs behavioral and biological variation among prehistoric Jomon foragers and Yayoi agriculturalists using bioarchaeological data. The Jomon were a group of foragers from Japan dating to approximately 13,000 until 2500 BP. The Yayoi were the first agriculturally dependent people on the Japanese islands, dating from 2500 until 1700 BP. Data collected from human skeletal remains were used to test the following hypotheses about these groups: 1) Patterns of systemic stress among prehistoric Jomon foragers was variable; 2) Systemic stress increased following the transition to agriculture; 3) Systemic stress patterns among Yayoi agriculturalists was variable; 4) Differences in body size and proportions will be observed among and between Jomon foragers and Yayoi agriculturalists; 5) Systemic stress experienced during the agricultural transition in prehistoric Japan was greater than other East Asian agriculturalists and improved compared with North American agriculturalists. Non-specific indicators of stress suggest the Jomon from western Japan experienced greater disease loads than those from eastern Japan. This trend is associated with plant dependent diets and resource scarcity in western Japan. Stature variation is, however, not recorded between these two groups indicating that systemic stress severity was not different between the eastern and western Jomon. Oral health declined following the transition to agriculture in prehistoric Japan in association with increased consumption of carbohydrates. Non-specific indicators of stress reduced in frequency following the transition to agriculture. These trends indicate that the quality of life for prehistoric Japanese was generally improved compared to prehistoric North American agriculturalists and similar to that observed in prehistoric East Asian agriculturalists. In addition, patterns of health observed among Yayoi agriculturalists, specifically enamel hypoplasia and stature variation, indicates that the Tanegashima Island Yayoi experienced greater levels of systemic stress than the Yayoi from Tanegashima Island and Northern Kyushu. Variation in body proportions among and between the Jomon and Yayoi is associated with morphological adjustment to climate and differences in systemic stress levels. The overall results of this dissertation suggest that biological and cultural responses to environmental variation crossed large portions of geographic and temporal space in prehistoric Japan. Advisors/Committee Members: Larsen, Clark (Advisor).

Subjects/Keywords: Anthropology, Physical; bioarchaeology; Japan; Jomon; Yayoi; dental anthropology; enamel hypoplasia; dental caries; ontogeny; stature; ecogeographic variation; body proportions; agriculture; human variation

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APA (6th Edition):

Temple, D. H. (2007). Human biological variation during the agricultural transition in prehistoric Japan. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1179521050

Chicago Manual of Style (16th Edition):

Temple, Daniel Howard. “Human biological variation during the agricultural transition in prehistoric Japan.” 2007. Doctoral Dissertation, The Ohio State University. Accessed December 10, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1179521050.

MLA Handbook (7th Edition):

Temple, Daniel Howard. “Human biological variation during the agricultural transition in prehistoric Japan.” 2007. Web. 10 Dec 2019.

Vancouver:

Temple DH. Human biological variation during the agricultural transition in prehistoric Japan. [Internet] [Doctoral dissertation]. The Ohio State University; 2007. [cited 2019 Dec 10]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1179521050.

Council of Science Editors:

Temple DH. Human biological variation during the agricultural transition in prehistoric Japan. [Doctoral Dissertation]. The Ohio State University; 2007. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1179521050


University of Cambridge

3. Payne, Stephanie. Phenotypic variation and thermoregulation of the human hand.

Degree: PhD, 2018, University of Cambridge

The hand has the highest surface area-to-volume ratio of any body part. This property offers the potential for the hand to serve an important function in thermoregulation through radiative heat loss. Theoretically, the capacity for heat loss may be influenced by hand and digit proportions, but the extent to which these proportions influence the hand's radiative properties remains under-investigated. Although hand morphology is highly constrained by both integration and functional dexterity, phenotypic variation in hand and digit proportions across human populations shows broad ecogeographic patterns. These patterns have been associated with climate adaptation. However, the theory linking climate adaptation to such ecogeographic patterns is based on underlying assumptions relating to thermodynamic principles, which have not been tested in vivo. This study sought to determine the influence of hand and digit proportions on heat loss from the hands directly, the additional anthropometric factors that may affect this relationship, and the impact of variation in hand proportions on dexterity in the cold. The relationship between hand proportions and thermoregulation was tested through both laboratory-based investigation and a field study. The laboratory investigation assessed the relationship between hand proportions and heat loss, the influence of body size and composition on this relationship, and the effect of morphological variation on manual dexterity. Participants (N=114; 18-50 years of age), underwent a 3-minute ice-water hand-immersion. Thermal imaging analysis was used to quantify heat loss. Hand and digit proportions were quantified using 2D and 3D scanning techniques; body size and composition were measured using established anthropometric methods and bio-impedance analysis. After accounting for body size, hand width, digit-to-palm length ratio, and skeletal muscle mass were significant predictors of heat loss from the hand, whilsthand length and fat mass were not. A separate set of participants (N=40) performed a Purdue pegboard dexterity test before and after the immersion test, which demonstrated that digit width alone negatively correlated with dexterity. The field study tested whether phenotypic variation in upper limb proportions could be attributed to cold adaptation or selection for dexterity in living populations exposed to significant energetic stress. Upper limb segment lengths were obtained from participants (N=254; 18-59 years of age), from highland and lowland regions of the Nepalese Himalayas using established anthropometric methods, and relative hand proportions were assessed in relation to severe energetic stress associated with life at high altitude. Relative to height, hand length and hand width were not reduced with altitude stress, whilst ulna length was. This indicates that cold adaptation is not shaping hand proportions in this case, although phenotypic variation in other limb segments may be attributed to cold adaptation or a thrifty phenotype mechanism. The current study provides…

Subjects/Keywords: Hand; dexterity; thermal imaging; Himalayas; surface area-to-volume ratio; cold; ice-water immersion; temperature; radiation; heat loss; digits; proportions; ecogeographic patterns; phenotypic variation; climate adaptation; anthropometry; body size; muscle mass; energetic stress; thrifty phenotype

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Payne, S. (2018). Phenotypic variation and thermoregulation of the human hand. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/285561 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.763716

Chicago Manual of Style (16th Edition):

Payne, Stephanie. “Phenotypic variation and thermoregulation of the human hand.” 2018. Doctoral Dissertation, University of Cambridge. Accessed December 10, 2019. https://www.repository.cam.ac.uk/handle/1810/285561 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.763716.

MLA Handbook (7th Edition):

Payne, Stephanie. “Phenotypic variation and thermoregulation of the human hand.” 2018. Web. 10 Dec 2019.

Vancouver:

Payne S. Phenotypic variation and thermoregulation of the human hand. [Internet] [Doctoral dissertation]. University of Cambridge; 2018. [cited 2019 Dec 10]. Available from: https://www.repository.cam.ac.uk/handle/1810/285561 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.763716.

Council of Science Editors:

Payne S. Phenotypic variation and thermoregulation of the human hand. [Doctoral Dissertation]. University of Cambridge; 2018. Available from: https://www.repository.cam.ac.uk/handle/1810/285561 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.763716

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