Major Department

Anthropology

College

College of Liberal Arts & Sciences

Degree

BS (Bachelor of Science)

Session and Year of Graduation

Spring 2019

Honors Major Advisor

Margaret Beck

Thesis Mentor

Robert G. Franciscus

Abstract

Biological anthropologists have long highlighted nasofacial differences between African and European populations, often regarding African-Americans as morphological proxies for Equatorial Africans in these endeavors. Despite the known mid-facial skeletal morphology distinctions between Equatorial Africans and ancestral Europeans, little is known about how admixture between these two populations affects African-American nasofacial morphology. It has been argued that the nasofacial region of the cranium is under high genetic heritability. However, substantial amounts of ancestral European DNA are present in the African-American populations due to historical contact between these two ancestral populations. The extent in which African-American populations have diverged away from ancestral African mid-facial morphology expectations in a significant way due to this genetic admixture is largely unknown. Here, we evaluate the extent to which European admixture and genetic structure in African-Americans has resulted in nasofacial and genomic divergence from the ancestral Equatorial African form, thus impacting their utility as morphological proxies for Equatorial African populations. The results of this study will highlight the significant divergence of African-Americans away from Equatorial Africans in both their morphology and genetic structure. It will also highlight the potential for inaccurate conclusions when using this admixed population in skeletal and genomic research studies as proxies for their assumed ancestral counterparts. This study supports previously cited average values of genetic admixture in African-Americans while also showing extreme individual morphological and genetic divergence from assumed ancestral types.

Keywords

nasofacial, morphology, admixture, African-American

Total Pages

27

Copyright

Copyright © 2019 Alexis S. Williams

COinS
 

URL

https://ir.uiowa.edu/honors_theses/291