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An Assessment of Microevolutionary Change among Prehistoric Florida Populations through the Analysis of Craniometric Data

The analysis of craniometric data collected from skeletal remains, combined with
archaeological data, can provide very valuable information pertaining to biological
distance and gene flow among prehistoric populations through space and time. The goal
of this study was to examine microevolutionary change among prehistoric populations in
south Florida based on the degree of cranial variation among populations at seven
prehistoric sites. It was expected that as time progressed, microevolutionary forces
caused significant changes in the crania of the various populations based on the relative
geographic proximity of the sites and the temporal distance between sites.
A Microscribe 3-DX digitizer was used to collect coordinate data using the full
protocol of cranial landmarks. Twenty-three interlandmark distances for n=223 skulls
from seven sites, ranging in age from 8120 B.P. to 260 B.P., were analyzed using Cluster
Analysis, an Analysis of Variance (ANOVA), a Tukey’s Pairwise Comparison (post-hoc
test), a Multiple Analysis of Variance (MANOVA), and Principal Components Analysis
(PCA) in SPSS 18.0. The seven sites were Windover (8Br246), Perico Island (8Ma6),
Captiva Island (8Ll57), Belle Glade (8Pb40), Horr’s Island (8Cr41), Safety Harbor
(8Pi2), and Fuller Mound A (8Br90). Of the 223 crania used, zero (0) skulls were 100%
complete.
Results of univariate and multivariate statistical analyses indicate that there are
significant differences among the seven groups. The agglomerative cluster analysis did
not provide significant results. When using Maximum Cranial Length (GOL), the
ANOVA (F=5.190, p ≤ 0.000) and post-hoc tests indicated that there was a significant
amount of variation among the seven populations. In a series of 12 MANOVA tests, it
was determined that significant variation existed between Windover and each of the
remaining six sites (F > 5, p ≤ 0.000). Additionally, the MANOVA tests indicated that
significant variation existed between Horr’s Island and Safety Harbor (F = 8.151, p ≤
0.000) and between Safety Harbor and Fuller Mound A (F = 5.549, p ≤
0.000). Last, a
Principal Components Analysis demonstrated that measurements consistent with length
or breadth accounted for the largest percentage of variation among the populations.
In conclusion, the data strongly demonstrate a significant amount of variation
among prehistoric populations as time progressed from 8120 B.P. to 260 B.P.
Specifically, changes in gene flow which can be attributed to significant differences
among populations based on craniometric data parallel major time gaps and historical
events in Florida. More generally, these results can be applied to other past populations
to investigate similar patterns of gene flow and changes that may have occurred due to
various social, political, and environmental stressors.

Identiferoai:union.ndltd.org:USF/oai:scholarcommons.usf.edu:etd-4857
Date05 November 2010
CreatorsSeasons, Samantha M.
PublisherScholar Commons
Source SetsUniversity of South Flordia
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceGraduate Theses and Dissertations
Rightsdefault

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