#54: Cladistic Ontogeny of Homo sapiens — Presentation Detail — Celebration of Scholars

Instructions

Student presentations must have a faculty sponsor.

Abstracts must include a title and a description of the research, scholarship, or creative work. The description should be 150-225 words in length and constructed in a format or style appropriate for the presenter’s discipline.

The following points should be addressed within the selected format or style for the abstract:

A clear statement of the problem or question you pursued, or the scholarly goal or creative theme achieved in your work.
A brief comment about the significance or uniqueness of the work.
A clear description of the methods used to achieve the purpose or goals for the work.
A statement of the conclusions, results, outcomes, or recommendations, or if the work is still in progress, the results you expect to report at the event.

Presenter photographs should be head and shoulder shots comparable to passport photos.

Additional Information

More information is available at carthage.edu/celebration-scholars/. The following are members of the Research, Scholarship, and Creativity Committee who are eager to listen to ideas and answer questions:

Jun Wang
Kim Instenes
John Kirk
Nora Nickels
Andrew Pustina
James Ripley

#54: Cladistic Ontogeny of Homo sapiens

Name: Chloe Harper
Major: Biology
Hometown: Hendersonville, TN
Faculty Sponsor: Thomas Carr
Other Sponsors:
Type of research: Independent research
Funding: Undergraduate Research, Scholarship, and Creativity Grant

Abstract

Coroners, forensic anthropologists, and archaeologists use different types of osteological data for determining age at death for anatomically modern humans (Homo sapiens); however, these data often conflict with one another and have limited precision and accuracy when used on their own. This study aimed to overcome these limitations through quantitative cladistic analysis and recover a growth series that includes all sources of dental and skeletal data.

The study included 14 partially complete crania and 13 cranial fragments from the Late Neolithic (3951-2620 BCE) Vertebra Cave site (western Ukraine) from the collections of the University of Wisconsin-Oshkosh. A new technology search in TNT recovered 100,000 growth series (TL = 113, CI = 0.50, RC = 0.23); a 50% majority rule consensus tree recovered six growth stages.

The consensus tree recovers a growth series with sexual dimorphism. The first growth stage (juveniles) is diagnosed by sutural bones, rounded frontal eminences, and ovoid foramina magna. The second growth stage is a polytomy that includes two unambiguous adult females and a cluster of unambiguous subadult males. The second growth stage is supported by the presence of temporal lines, lateral projection of the zygomatic process, the supraorbital margin transitions from sharp to dull, the presence of a small nuchal crest, the median nuchal line extends to the superior nuchal line, and a patent condylar canal. The adult females are united by the absence of nasal foramina and the presence of an ovoid-shaped external acoustic meatus (EAM). The subadult males are united by enlarged glabellar ridges, intermediate mastoid processes (approx. 2x the size of the EAM), and supraorbital margins that transition from thin to thick.

The third growth stage (adult males) is diagnosed by the presence of at least one mastoid foramen. The fourth growth stage is supported by a thick supraorbital margin with minimal curvature. The fifth growth stage (hypermasculine adult males) is diagnosed by massive glabellar ridges, distinct nasal foramina, and circular-shaped EAM. The sixth growth stage (VC.HR10) is diagnosed by inferiorly projecting, massive mastoid processes, and a circular overall head shape.

The growth series is too low resolution to determine the precise chronological age of the specimens, but the series is broadly consistent with chronological age: the first stage (juveniles) includes all specimens 17 years of age and younger (determined by dental eruption data), while later growth stages consist of mature adults only. The congruence between size and maturity was assessed using a Spearman Rank correlation test (size rank data are normal, Shapiro-Wilk p = 0.93), which is not significant (rS(0.05, 7) = 0.51, p = 0.19).

Poster file