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          • Bio
          • Publications
          • Public Science
          • Research
          • Teaching
          • Funding
          • Contact
          • Alexandra Kralick

            Ph.D. Candidate at University of Pennsylvania

            Biological Anthropology · Great Apes · Orangutans · Life History · Growth and Development · Osteology and Osteobiographies · Sex Dimorphism (Sex Differences) · Feminist & Queer Biology · Growth and Development · Functional Morphology

          • Bio

             

            Alexandra Kralick is a PhD candidate at University of Pennsylvania scheduled to defend her dissertation and graduate in the spring of 2023. She studies life history and functional morphology of sex differences in the great ape skeleton.

             

            Her dissertation focuses on the skeletons of two types of male orangutans, flanged and unflanged. She developed a novel holistic methodology to identify the morphology and maturation of flanging status in museum collections.

             

            As an anthropologist trained in a four-field approach, she pushes disciplinary boundaries by engaging with queer theory to showcase how great ape skeletons defy normative expectations of biological sex and gender. She has been integrating contextual reflexivity and decolonial theory to foster conversations regarding ethics and equity in great ape skeletal research.

             

            She earned her B.S. in Biological Anthropology from The George Washington University in 2014 where she studied gorilla dental development and wrist bone shape. 
            CV
          • Publications

            Peer Reviewed Journal Articles

            More severe stress markers in the teeth of flanged versus unflanged orangutans (Pongo spp.)

            First Author

            Publication available here

            Alexandra E. Kralick and Kate McGrath. (2021). More severe stress markersin the teeth of flanged versus unflanged orangutans (Pongo spp.). American Journal of Physical Anthropology. 1:13. DOI: 10.1002/ajpa.24387

            Faster growth corresponds with shallower linear hypoplastic defects in great ape canines

            Contributing Author

            Publication available here

            McGrath, K., Reid, D.J., Guatelli-Steinberg, D., Arbenz-Smith, K., El Zaatari, S., Fatica, L.M., Kralick, A.E., Cranfield, M.R., Stoinski, T.S., Bromage, T.G. and Mudakikwa, A., 2019. Faster growth corresponds with shallower linear hypoplastic defects in great ape canines. Journal of Human Evolution, 137, p.102691

            Evolutionary perspectives on the developing skeleton and implications for lifelong health

            First Author

            Open source publication available here

            Alexandra E. Kralick and Babette S. Zemel. (2020). Evolutionary perspectives on the developing skeleton and implications for lifelong health. Frontiers in Endocrinology. 11: 99. doi: 10.3389/fendo.2020.00099

            A radiographic study of permanent molar development in wild Virunga mountain gorillas of known chronological age from Rwanda

            First Author

            Publication available here

            Alexandra E. Kralick, M. Loring Burgess, Halszka Golwacka, Keely Arbenz-Smith, Kate McGrath, Christopher B. Ruff, King Chan, Michael R. Cranfield, Tara S. Stoinski, Timothy G. Bromage, Antoine Mudakikwa, Shannon C. McFarlin. (2017). A radiographic study of permanent molar development in wild Virunga mountain gorillas of known chronological age from Rwanda. American Journal of Physical Anthropology. 163(1):129-147.

            Google Scholar
            Research Gate
          • Public Science Communication

             

            Anthropology News Article

            "When Ape Sex Isn’t Simple: One type of male orangutan has perplexed scientists because they run counter to long-held binary expectations of sex differences in the skeleton."
             

            Frontiers for Young Minds Article

            "Habitat Destruction Is Affecting The Facial Features Of Orangutans"

            Frontiers for Young Minds is an open access scientific journal that brings the latest research in real time to school kids

             

            Leakey Foundation Lunch Break Science Webinar

            "Orangutan skeletons bust the sex binary"

             

            Smithsonian HOT Topic Webinar

            "Climate change threatens great ape biology"

             

            Popular Science Article Sex in the Skeleton

            "What our skeletons Say about the Sex Binary" Republished at The Atlantic and Slate.

             

            University of Pennsylvania Grad Ben Talk

            "What our Skeletons Say about the Sex Binary"

             

            The Arch & Anth Podcast Episode

            Episode 125: How do orangutan skeletons grow? What are some fun biological anthropology facts?

             

          • Ongoing Research Projects

            Body Size Variation among Adult Male Orangutans and its Implications for Sexual Dimorphism in Pongo spp.

            Orangutans are typically described as exhibiting high sexual dimorphism between males and females, although they also show pronounced within-sex size differences. All males eventually become flanged males, with large cheek pads (flanges) and throat pouches. Most males develop flanges during puberty, but not always. Some males delay the maturation of flanges for anywhere from a few to 20 years. These phenotypically “immature” but reproductively capable males are called adult unflanged males. Orangutan skeletons from wild-shot individuals in museum collections offer a unique opportunity to measure features that correlate with body size, such as long bone length, strength, and bi-iliac breadth. We measured adult orangutan skeletons from museums across the USA and Europe. Our results show that adult unflanged male sizes ranged between those of adult flanged males and adult females. These findings indicate that orangutans are not a sexually dimorphic species per se, and raise intriguing questions about the factors that shape male orangutan phenotypic and sexual maturation in the wild.

            Manuscript submitted and in review in Integrative and Comparative Biology, e-mail me for a pre-print or request here

             

             

            Defects in Flanged and Unflanged Male Orangutan Canine Teeth

            We compared an early life stress indicator, linear enamel hypoplasia (LEH), in the canine teeth of two male orangutan (Pongo spp.) morphs. Flanged males have large bi-discoid cheek pads and a laryngeal throat pouch, and they exhibit either the same or higher levels of the stress hormone cortisol throughout development compared to unflanged males, which lack secondary sexual characteristics. Such ‘developmental arrest’ is hypothesized to either reflect a response to experienced high stress (Hypothesis 1), or an adaptation to avoid elevated stress levels and/or having experienced lower stress levels (Hypothesis 2) during early life. As LEH defect depth has been shown to reflect the severity (i.e., intensity and/or duration) of early life stress events, we examined whether unflanged males have shallower LEH defects than flanged males. Flanged males have significantly deeper LEH defects than unflanged adult males. Canine projected crown heights are similar across males regardless of morph. Evidence from great apes shows that, when comparing canines with similar growth patterns, deeper defects reflect more severe stress events during development. Thus, our results suggest that ‘developmental arrest’ of unflanged males is not a response to having experienced stress, but rather an adaptation to avoid the physiological impacts associated with chronic stress and/or experiencing lower stress levels.

            Link to manuscript

            Conference poster available here

            Lost Lives of Orangutans: Restoring Identities to Great Apes in Museum Collections Research

            I organized an American Anthropological Association (AAA) invited podium symposium that focused on decolonial theory, contextual reflexivity, and animal ethics in great ape skeletal remains research. The panelists and I developed a manuscript for Evolutionary Anthropology that discusses best practices for improving standards of research on and curation of ape remains. The paper currently in review in Evolutionary Anthropology encourages scholars to consider their own positionality when studying ape remains and provides recommendations for making access to remains more equitable, such as centering and amplifying voices in the Global South in conversations and actions, including digital repatriation and co-ownership of remains. The resulting recommendations include contextualizing the individual, piecing individuals back together, challenging/questioning the captive-wild dichotomy, and collaborative international conversations. This serves as one example of how we can be decolonizing our respective research within biological anthropology.

            Manuscript submitted and in review in Evolutionary Anthropology, e-mail me for a pre-print

             

            Conference Slides available here

            Relative leg-to-arm strength proportions in Bornean and Sumatran orangutans

            Differences in habitat continuity and predators have been posited as explanations for higher rates of terrestrial locomotion in Bornean compared to Sumatran orangutans. However, it is unclear whether greater terrestriality in Bornean orangutans is due to recent environmental changes to their habitats. Orangutan skeletons collected a century ago may shed new light on this question as habitat continuity on both islands would have been greater in the past. In this study, cross-sectional geometry ratios were calculated for orangutans from CT scans. Both orangutan taxa show significantly less relative leg-to- arm strength than all gorillas, even those that climb the most (i.e., western lowland gorillas and infant mountain gorillas). Moreover, Bornean orangutans display limb bone strength proportions that are consistent with more terrestriality than their Sumatran counterparts. Thus, recent habitat discontinuity in Borneo does not explain greater terrestriality in Bornean orangutans, as also suggested by camera trap data, and is most likely due to the absence of tigers on Borneo.

            Manuscript in preparation

             

            Conference Slides available here

            Mentee Project:

            Evidence of orangutans compensating for broken and re-healed arm bones using other limbs

            Sarah Caminito's Undergraduate Senior Thesis investigates the oranguans in museum collections who broke and re-healed their long bones using a combination of CT scan methodologies

             

            3D analysis of gorilla wrist shape

            African apes are all primarily terrestrial knuckle-walkers but western lowland gorillas (Gorilla gorilla gorilla) climb more frequently than do eastern gorillas (Gorilla beringei), a consequence of ecological differences in their respective habitats. Although bonobos (Pan paniscus) have generally been assumed to be more arboreal than common chimpanzees (Pan troglodytes), recent fieldwork suggests this is not true. We tested whether western lowland gorillas, being relatively more arboreal, exhibit trapezium morphology that enhances pollical grasping ability in comparison to eastern gorillas, whereas trapezoid morphology should vary less among gorillas given its functional role in weight support during knuckle-walking. In contrast, common chimpanzees and bonobos should be more similar to one another in terms of both trapezium and trapezoid morphology. Using 3D geometric morphometrics, our results follow some of the expected predictions in that western lowland gorilla trapezia are distinguishable from those of eastern gorillas in ways that are reasonably attributable to pollical grasping. Overall, these results underscore the challenges of identifying functionally relevant shape variation in hominoid carpal bones while also highlighting a large amount of unexpected carpal shape variation within African ape taxa that is probably best explained by genetic drift.

             

            Poster available here

            Sex and Age Based Differences in Orangutan Long Bone Cross-Sectional Dimensions & Climbing Rates

             

            Coming soon!

          • Teaching

            Principal Instructor of Record

            2022, 2021, 2020 ANTH 003 920- Intro Human Evolution, University of Pennsylvania

            2022 PSPR 005 920- BioCultural Anthropology of Sex and Gender, University of Pennsylvania

            2021 PSPR 023 920- Myths of Human Nature, University of Pennsylvania

            2021 Human Osteology, Penn Museum Archaeological Field Skills Bootcamp, University of Pennsylvania

            Graduate Teaching Assistant

            2018, 2017 ANTH 003- Intro Human Evolution, University of Pennsylvania

            2018 ANTH 122- Becoming Human, University of Pennsylvania

            2018 ANTH 207- Primate Behavior and Ecology, University of Pennsylvania

            K-12 Teaching Experience

            2014-2015 High School Science Teacher, Teach for America; Potomac High School, 5211 Boydell Ave, 12, Oxon Hill, Maryland 20745

            2015-2016 Education Program Intern, Student Conservation Association; C&O Canal National Historic Park, Great Falls

            Mentorship

            Undergraduate Research Mentees:

            2021-Present Sarah Caminito

            2021-Present Clara Nolan

            2022-Present Morgan West

            2021-Present Jocelyn Salgado

            2019-2020 Phoebe Stokes

            2019-2020 Anne Lally

          • Student Class Projects

            Select student media projects created to bust misconceptions!

          • A big thank you to my funding sources

            NSF (National Science Foundation)

            • National Science Foundation Graduate Research Fellowship Grant (NSF GRFP)
            • National Science Foundation Graduate Research Internship Program (NSF GRIP)
            • National Science Foundation Smithsonian NHRE (Natural History Research Experiences) Program REU (Research Experiences for Undergraduates) Internship

            The Leakey Foundation

             

            • Dissertation Research Grant

            P.E.O. (Philanthropic Education Organization)

             

            • P.E.O Scholar Award

            AABA (American Association of Biological Anthropologists)

            • Pollitzer student travel award

            Penn Museum

            • Summer Field Funds

            University of Pennsylvania

            • Dissertation Completion Fellowship
            • Teece Dissertation Research Funds
            • Presidential Graduate Prize Fellowship, School of Arts and Sciences
            • Benjamin Franklin Fellowship, School of Arts and Sciences

            George Washington University

            • George Gamow Undergraduate Research Fellowship
            • Luther Rice Undergraduate Research Fellowship
          • Contact

            Feel free to each out over email or twitter.

            akralick@sas.upenn.edu

            Email

            Twitter

          © 2022 by Alexandra Kralick

          Photos are not for reproduction

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