modern variation and evolutionary change in the hominin eye orbit

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length of the anterior and middle cranial fossae decreases in association with an increasein relative length and height of the face. These cranial fossae continue to shorten afterneural growth is complete, and facial height and length continue to increase in associationwith facial projection (Lieberman, McBratney, Krovitz, 2002). By contrast, the facestays retracted beneath the anterior cranial base and the neurocranium remains highlyglobular during ontogeny in Homo sapiens.Cranial globularity is a unique feature of modern human skulls and is largely theresult of increased cranial base flexion and changes in relative size of certain brainstructures. Expansion of the frontal and temporal lobes of the brain are an importantcomponent of this flexion, as they act to lengthen the anterior cranial base and influencethe size of the anterior and middle cranial fossae, respectively (Lieberman, McBratney,Krovitz, 2002).In addition to an increase in relative size of these basicranial components,anatomically modern Homo sapiens are characterized by a distinct forward and lateralexpansion of the anterior portion of the middle cranial fossa relative to the optic andmaxillary nerve foraminae compared to archaic Homo sapiens and Homo erectus (Bastir,et al. 2008). As a result of this anterior movement of the middle cranial fossa relative tothese nerve foraminae, the maxillary tuberosities and the orbits are also shifted anteriorlyin relation to basicranial and neurocranial structures (Bastir et al. 2008).Forward movement of the middle cranial fossa also correlates with forwardprojection of the greater sphenoid wings, which shift the posterior maxillary planeanteriorly, rotating it clockwise when viewed laterally from the right side (Bastir et al.2008; McCarthy & Lieberman, 2001). The vertical boundary of the posterior maxillary17
plane is highly related to factors influencing the basic design of the face, and isconsidered one of the most important structural and developmental planes of the entirecraniofacial complex (Enlow & Hans, 1996). This plane is tightly constrained at 90relative to the anterior cranial base in humans and non-human primates (Bastir et al.2008; Enlow, 1990; Lieberman, Ross, Ravosa, 2000; Lieberman, McBratney, Krovitz,2002; McCarthy & Lieberman, 2001), and is also constrained at 90 relative to theneutral horizontal axis throughout growth and development in all mammals (Bromage,1992; Enlow & Hans, 1996).An increase in relative size of the frontal and temporal lobes of the brain,expansion and forward movement of the anterior and middle cranial fossae, forwardprojection of the greater sphenoid wings, and rotation of the posterior maxillary planethus act to create the uniquely globular cranium and ventrally rotated face that lies underthe anterior cranial fossa in anatomically modern humans (Bastir et al. 2008; McCarthy& Lieberman, 2001; Lieberman, McBratney, Krovitz, 2002).Throughout hominin evolution a marked increase in neocortical volume hasoccurred in which the frontal, temporal, occipital, and parietal lobes have expanded inassociation with increased intellectual capacity (Bastir et al. 2008; Rilling, 2006; Wu etal. 2007). As described above, these changes are associated with modification tounderlying basicranial and facial structures, and have resulted in a more anteroposteriorlyshorter face through time. However, the extent to which the entire skull has rotated, andthe face and orbits have become tucked up under the brain, is a unique derived feature ofanatomically modern humans (Cobb, 2008; Bastir et al. 2008; Lieberman, McBratney,Krovitz, 2002).18
Page 1: MODERN VARIATION AND EVOLUTIONARY C
Page 7 and 8: VITAJanuary 2, 1978……………
Page 9 and 10: TABLE OF CONTENTSPageAbstract .….
Page 11 and 12: 7. Summary and Conclusion………
Page 13 and 14: Table 3.13: Wilks' lambda and Chi-s
Page 15 and 16: Figure 5.4: Change in orbital bread
Page 17 and 18: Although there is a great deal of c
Page 19 and 20: extent that in modern humans it sit
Page 21 and 22: in the face and cranium” (Enlow &
Page 23 and 24: etween the neurocranium and face, u
Page 25 and 26: Schultz (1940) observes a negative
Page 27 and 28: sphenoid, and between 5 and 6 in th
Page 29 and 30: its relative position during forwar
Page 31: fact more variation exist between r
Page 35 and 36: cranial and facial height occurs in
Page 37 and 38: assessed in relation to patterns of
Page 39 and 40: or throughout hominin evolution cou
Page 41 and 42: in roughly the same proportions (An
Page 43 and 44: association with juvenile-onset myo
Page 45 and 46: Craniofacial Variables Label Landma
Page 47 and 48: In this investigation the FH is not
Page 49 and 50: this study most research questions
Page 51 and 52: Craniofacial Variables Label ErrorC
Page 53 and 54: CHAPTER 3MODERN HUMAN VARIATION IN
Page 55 and 56: Sample Sample Size RepositoryAfrica
Page 57 and 58: change in orbital anatomy and will
Page 59 and 60: 3.3.1 Interorbital breadth and bior
Page 61 and 62: 3.3.2 Orbital height and orbital br
Page 63 and 64: Basion-Superior Orbit, Basion-Infer
Page 65 and 66: 98Vertical Angle of Orbital Margins
Page 67 and 68: statistical tools. In the next sect
Page 69 and 70: Correlation obbobhobdobvobfekbdkbbs
Page 71 and 72: obbobhobdobvobfekbdkbbsobioFunction
Page 73 and 74: variables in the first discriminant
Page 75 and 76: distance matrix, which shows the Af
Page 77 and 78: golxcbzybbbhbplufbnphnlhobbobhobdob
Page 79 and 80: non-orbital cranial and facial trai
Page 81 and 82: Function 242012AncestryAfricanAsian
Page 83 and 84:
eadth (ekb), and basion-orbitale (b
Page 85 and 86:
CHAPTER 4EVOLUTIONARY CHANGE IN THE
Page 87 and 88:
This sample represents the most mor
Page 89 and 90:
analysis. This was done to remove a
Page 91 and 92:
190Boxplot of Cranial Size vs Time1
Page 93 and 94:
flexed in association with neurocra
Page 95 and 96:
Variables N Coefficient t p R²1) B
Page 97 and 98:
Ross (1995) also finds a relationsh
Page 99 and 100:
Figure 4.4: Image of Shandingdong (
Page 101 and 102:
CHAPTER 5EVOLUTIONARY CHANGE IN THE
Page 103 and 104:
ecause of a general reduction in cr
Page 105 and 106:
adequate space within the orbits fo
Page 107 and 108:
Western European temporal groups sa
Page 109 and 110:
Upper Paleolithic (Figure 5.4). The
Page 111 and 112:
Regardless of the relative contribu
Page 113 and 114:
of facial projection vs. time indic
Page 115 and 116:
Boxplot of Cranial Index vs Time908
Page 117 and 118:
5.6 Results of regression analyses:
Page 119 and 120:
Although the direction and magnitud
Page 121 and 122:
Additionally, because the eyeball s
Page 123 and 124:
corroborates the findings of other
Page 125 and 126:
Sample Sample Sizes Method DataFema
Page 127 and 128:
approximately 3.5 show little to no
Page 129 and 130:
In females there is a clear differe
Page 131 and 132:
Boxplot of Orbital Vol vs Sex25.022
Page 133 and 134:
Ancestral Group N mean s.d. t pAfri
Page 135 and 136:
5.5Boxplot of Relative Eye Size vs
Page 137 and 138:
away from emmetropia in individuals
Page 139 and 140:
ceases. Additionally, different pat
Page 141 and 142:
of the orbit that the eyeball fills
Page 143 and 144:
CHAPTER 7SUMMARY AND CONCLUSION7.1
Page 145 and 146:
margins in this group. The slightly
Page 147 and 148:
classification of dry skulls and as
Page 149 and 150:
Six orbital variables were used to
Page 151 and 152:
A final prediction relating to how
Page 153 and 154:
Nevertheless, orbital traits that c
Page 155 and 156:
etraction could not be evaluated. H
Page 157 and 158:
A statistically significant negativ
Page 159 and 160:
to engage in non-subsistence activi
Page 161 and 162:
comes at a cost to visual acuity ho
Page 163 and 164:
trajectories between the eye and or
Page 165 and 166:
BIBLIOGRAPHYAiello, L., Dean, C. (1
Page 167 and 168:
Bruner, E., Saracino, B., Passarell
Page 169 and 170:
Goldschmidt, E., Lam, C., Opper, S.
Page 171 and 172:
Lam, C., Edwards, M., Millodot, M.,
Page 173 and 174:
Quant, J., Woo, G. (1992) Normal va
Page 175:
Weiss, K. (2002) How the Eye Got it
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modern variation and evolutionary change in the hominin eye orbit

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