Cranial size in relation to body mass and skeletal robusticity in modern humans

96 Pages·2002·4.3 MB·English

by  Stubblefield, Phoebe Regina

CRANIALSIZEINRELATIONTOBODYMASSANDSKELETALROBUSTICITY
INMODERNHUMANS
By
PHOEBEREGINASTUBBLEHELD
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULHLLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
2002
Copyright2002
by
PhoebeReginaStubblefield
,
ACKNOWLEDGEMENTS
IfirstwanttothankGodforgettingmethroughthisdoctoralprocess. Ialsowant
tothankthelateDr.WilliamR.MaplesandDr.SusanAntonfortheirmentorshipand
instructionwhichledmetoandthroughtheUniversityofFlorida. IalsothankDr.Sue
Boinskiforherleadershipandencouragement. MythanksgotoDr.AnthonyFalsetti
Dr.ThomasHollinger,andDr.WilliamHamiltonfortheirhelpduringthisprocess. My
specialthanksgotoMargaretandHerbGillilandfortheirgraciousandgeneroussupport
andconcern. ManythanksgototheAmericanAcademyofForensicSciences'Lucas
GrantandtheNationalAcademiesFordFoundationFellowship,andthedoctorsand
techniciansofthemedicalexaminers'officesinFloridaandMichigan,withoutwhich
andwhomthisworkwouldnothavebeenpossible. LastofallIwanttothankmy
parentsfortheirsupport,Pamelafortranscribingdata,andmytwin,Peggy,forbeing
therewhenIneededher.
iii
TABLEOFCONTENTS
ACKNOWLEDGEMENTS
iii
LISTOFTABLES vi
LISTOFHGURES ix
ABSTRACT x
INTRODUCTION 6
BodyWeightEstimationinHominids 2
ResearchwithEctocranialMeasurements 4
ResearchwithCranialThicknessMeasurements 4
LITERATUREREVIEW 9
PenslerandMcCarthy(1985) 9
Hartwig-SchererandMartin(1992) 9
Nawrocki(1992) 10
AielloandWood(1994) 12
Gauld(19%) 13
Discussion 14
TheProject 15
MATERIALSANDMETHODS 18
SampleSelection 18
DataCollection 19
SomaticVariables 19
CranialMeasurements 21
PostcranialMeasurements 25
EstimationofLeanBodyWeight 26
DataAnalysis 27
RESULTS 31
TheCombinedSample:DescriptiveStatistics 31
CombinedSample:RelationshipsBetweenVariables 33
CombinedSample:PrincipalComponentAnalysis 39
CombinedSample:RegressionAnalysis 43
TheAutopsyandSkeletalSamples:SomaticDescriptiveStatistics 44
QualityofSkinfolds 45
AutopsyandSkeletalSamples:CranialDescriptives !!!!."."."!!."!!!!.50
AutopsyandSkeletalSamples:RelationshipsBetweenVariables ....53
iv
AutopsyandSkeletalSamples:PrincipalComponentAnalyses 58
AutopsySample:RegressionAnalysis 63
Summary 64
DISCUSSION 67
REFERENCES 73
APPENDIX 80
BIOGRAPHICALSKETCH 84
V
LISTOFTABLES
Table page
1 AielloandWood'sresultsrelativetobodyweightusingamixedhominoid
sample 14
2 Cranialmeasurements 23
3 Claviclemeasurements 25
4 Resultsoftheone-samplet-testforsectionedandradiographicclavicle
measurements 26
5 Descriptivestatisticsforsomaticvariablesinthecombinedsample 31
6 Descriptivestatisticsforcranialvariablesofthecombinedsample 32
7 ComparisonofsharedectocranialmeasurementsinHowell's"mixedrace"
sampleandthecombinedsample 32
8 Descriptivestatisticsforclaviclevariablesinthecombinedsample 33
9 Combinedsamplecorrelationcoefficientsbetweenbodyweightandthe
somaticvariables(includingclavicle) 34
10 Combinedsamplecorrelationcoefficientsbetweenbodyweightandthe
cranialvariables 34
11 Combinedsamplecorrelationcoefficientsbetweentheclaviclecortical
thicknessandcranialthicknessvariables 35
12 Combinedsamplecorrelationcoefficientsbetweentheectocranialandcranial
thicknessvariables 36
13 Combinedsamplecorrelationcoefficientsbetweenectocranialandaverage
thicknessvariables 33
14 Combinedsamplecorrelationcoefficientsbetweenthecranialindexand
cranialthicknessvariables 33
15 Combinedsamplecorrelationcoefficientsbetweenthecranialindexshape
categoriesandthecranialthicknessvariables 39
16 Combinedsamplecorrelationcoefficientsbetweencranialindexcategories
andaveragevaultthickness 39
vi
17 Combinedsampleprincipalcomponentsusingallvariables(exceptage) 41
18 Combinedsampleprincipalcomponentsofthecranialvariablesandbody
weight 42
19 Combinedsampleregressioncoefficientsforbodyweightversusthecranial
variables 44
20 Descriptivestatiticsforthesomaticvariablesintheautopsyandskeletal
samples 45
21 AutopsysamplefatnesscategoriesbasedonFrisancho(1990)tableiv39for
malesusingsummedtricepsandsubscapularskinfoldvalues 46
22 Autopsysampleweightclassificationsbasedonweight(kg)andstature(cm)
andskinfolds 47
23 Contingencytableofweightclassificationsbasedonweightforstatureand
combinedtricepsandsubscapularskinfoldthicknesses 48
24 Regressionequationsforestimatingbodydensity(d)fromthelogarithmof
tricepsandsubscapularskinfoldmeasurements 48
25 Autopsysampledescriptivestatisticsforfatweightestimatesandthenew
variableleanweight 49
26 Weightclassificationsbasedonunadjustedweightforheightversuslean
weightforheight 49
27 Autopsysampledescriptivestatisticsforthecranialvariables 50
28 Skeletalsampledescriptivestatisticsofthecranialvariables 51
29 Autopsyandskeletalsamplesdescriptivestatisticsforclaviclevariables 52
30 Autopsyandskeletalsamplestwo-tailedt-testforthecranialvariables 52
31 Autopsyandskeletalsamplescorrelationcoefficientsbetweenbodyweight
andthesomaticandclaviclemeasurements 53
32 Autopsyandskeletalsamplescorrelationcoefficientsbetweenbodyweight
(kg)andtheectocranialvariables 54
33 Manipulatedskeletalsamplecorrelationcoefficientsforselect
variables 55
34 Skeletalsamplecorrelationcoefficientsforbodyweightversuscranial
variablesexcludinglowweightsubject 57
35 Autopsyandskeletalsamplescorrelationcoefficientsbetweenbodyweight
(kg)andthecranialthicknessvariables 58
36 Skeletalsamplecorrelationcoefficientsforadditionalectocranialvariables
versusvaultthicknessaverages 58
vii
37 Autopsysampleprincipalcomponentsforthecranialvariables 60
38 Skeletalsampleprincipalcomponentsusing£illvariables(exceptage) 61
39 Skeletalsampleprincipalcomponentsusingthecranialvariables 63
40 Autopsysampleregressioncoefficientsforbodyweightversuscranial
variables 64
41 Autopsysampleregressioncoefficientsforleanweightversuscranial
variables 65
viii
LISTOFnOURES
Figure page
1 EctocranialMeasurements 24
2 LocationsofCranialThicknessMeasurements 24
3 SkeletalSampleWeightforHeightClassDistribution 56
ix
AbstractofDissertationPresentedtotheGraduateSchool
oftheUniversityofFloridainPartialFulfillmentofthe
RequirementsfortheDegreeofDoctorofPhilosophy
CRANIALSIZEINRELATIONTOBODYMASSANDSKELETALROBUSTIOTY
INMODERNHUMANS
By
PhoebeReginaStubblefield
December2002
ChairSusanAnt6n
Cochair:SueBoinski
MajorDepartment:Anthropology
Bodyweightiscriticaltounderstandingprimatebiology.However,taphonomic
processeshamperacquiringthisstatisticfromhumanskeletonsorfossilhominids. Fossil
hominidspeciesaredefinedfromcraniathatfrequentlylackassociatedpostcrania. Thus
bodysizeinformationisfrequentlyrestrictedtothatwhichcanbeextractedfromtheskull.
Toaddressthisissue,Idesignedastaticallometricstudyusingmodemhumansasthe
referencesample.
Itestedtwohypothesesregardingtherelationshipbetweencranialsizeandbody
size. Thefirsthypothesisstatedthatmeasurementsofexternalcranialdimensions
(ectocranial)covarywithbodyweight,andthesecondthatcranialvaultthickness
measurementscovarywithbodyweightinrelationtosystemicskeletalrobusticity.Totest
thesehypothesesIsampled147adultsofknownbodyweight(100fromtheTerry
collectionattheNationalMuseumofNaturalHistoryand47fromrecentautopsies)for
X