05 03 29

Slide1: 

Patterns of Growth and Development in Fossil Hominin Browridge Morphology Jodi Blumenfeld Department of Anthropology University of Illinois, Urbana-Champaign (Márquez et al., 2001)

Slide2: 

KNM-ER 1470: Homo rudolfensis Koobi Fora, Kenya ~ 1.8-1.9 million years ago OH 24: Homo habilis Olduvai Gorge, Tanzania ~ 1.8 million years ago KNM-ER 1813: Homo habilis Koobi Fora, Kenya ~ 1.9 million years ago Homo habilis/rudolfensis Africa, ~2.3 – 1.7 million years ago (mya): (Wood and Collard, 1999)

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Homo ergaster (Eurasia & Africa): Homo erectus (E. Asia): KNM-ER 15000 Kenya ~ 1.6 mya KNM-ER 3733 Kenya, ~ 1.75 mya D2700 Georgia, ~ 1.8 mya Trinil 2 Indonesia, ~ 500,000 ya Sangiran 17 Indonesia, ~ 800,000 ya (Rightmire, 1998) Sambungmacan 3 Indonesia, ~ 1 mya – 100 kya (Márquez et al., 2001) (Vekua et al., 2002)

Slide4: 

OH 9 Kenya, ~ 1.2 mya Homo ergaster?

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Homo heidelbergensis (~ 600,000 ya – 300, 000 ya): Broken Hill 1 (Kabwe) Zambia, Africa ~ 400 kya Atapuerca 5 Sierra de Atapuerca, Spain ~ 300 kya Petralona 1 Petralona, Greece ~ 400 - 300 kya (Rightmire, 1998) (Rightmire, 1998) (Arsuaga et al., 1993)

Slide6: 

Neandertals (~ 125,000 – 24,000 ya): La Chapelle-aux-Saints France, ~ 50,000 ya Amud 1 Israel, ~ 40-50,000 ya

Slide7: 

Boule’s (1909) Neandertal reconstruction

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Neandertal juveniles: (Ponce de León and Zollikofer, 1999) Le Moustier 1 (~15 yrs old) France, ~ 45, 000 ya (Minugh-Purvis et al., 2000) Krapina 1 Croatia, ~ 130 kya

Slide9: 

Skhul 5 Israel, ~ 90,000 ya Cro-magnon 1 France, 30-32,000 ya Early anatomically modern Homo sapiens: (Shea, 2003)

Slide10: 

Female vs. Male Skull variation in browridge form related to sexual dimorphism females: smaller and less prominent browridges than in males, sharper upper orbital margins males: larger and more prominent browridges than in females, rounder upper orbital margins

Slide11: 

Early Hypotheses for Browridge Development: produced by frowning due to physical pain protection of the eyes from blows to the head protection from sunlight to produce effective intimidation stare to counter masticatory stresses generated by chewing

Slide12: 

Grover Krantz – Washington State University Browridge experiment in 1973 (Image is from Stringer and McKie, 1996: pg 91)

Slide13: 

The Frontal bone… high rate of preservation often is one of the only complete bones preserved in an individual varies by age, sex and species, and therefore may be an especially sensitive indicator of these attributes Lacave (Image from Smith et al., 1999)

Slide14: 

Heterochrony: changes in size and shape in an ancestor-descendent relationship occurs when descendent shapes result from changes in the growth patterns of ancestral shapes Ontogeny (growth and development): ontogenetic studies are crucial in understanding the evolution of hominin morphology morphological evolutionary changes must appear in ontogeny similar adult morphologies can be produced through different ontogenetic pathways

Slide15: 

ShapeCam System by Eyetronics (photo taken from: www.avl.iu.edu/~jlrogers/ 3DCameras/BuyResearch/)

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An anatomically modern human neonate skull showing the projected ShapeCam shadow grid (Blumenfeld et al., 2005)

Slide17: 

Neandertal 1 fossil specimen (Blumenfeld et al., 2005) (Blumenfeld et al., 2005) (Blumenfeld et al., 2005)

Slide18: 

Three-dimensional model of the Broken Hill (Kabwe) Homo heidelbergensis individual. (© 2004, Jodi Blumenfeld; Imaging Technology Group; Beckman Institute; and University of Illinois)

Slide19: 

Craniofacial landmarks used in this pilot study 1. Glabella (g) 9. Sulcus 2. Nasion (n) 10. Midpoint between sulcus and ft (right) 3. Frontotemporale (ft) (right) 11. Midpoint between sulcus and ft (left) 4. Frontotemporale (ft) (left) 5. Frontomalare temporale (fmt) (right) 6. Frontomalare temporale (fmt) (left) 7. Midpoint between n and fmt (right) 8. Midpoint between n and fmt (left) Fifteen 3D coordinate data points also selected for right-side parasagittal contour profiles pilot sample: 1 adult gorilla, 1 adult H. heidelbergensis (Kabwe), 1 adult Neandertal, 1 juvenile Neandertal ( La Quina, ~ 8 yrs old), 1 adult H. sapiens, 2 juvenile H. sapiens (~ 6 yrs old) and 1 neonatal H. sapiens data were then subjected to Generalized Procrustes Analysis (GPA) and Principal Components Analysis (PCA) in order to assess size and size-related shape changes in this region of the skull

Slide20: 

Generalized Procrustes Analysis: 11 3D craniofacial landmark configuration 15 3D parasagittal data points (right-side contour) superimposition and scaling for size using GPA shows shape differences in frontal bone form (Blumenfeld et al., 2005) (Blumenfeld et al., 2005)

Slide21: 

Principal Components Analysis (PCA): 11 landmark configuration PCA of the 11 landmark coordinates for all specimens included in this study. PC I, horizontal axis, 69% of variance; PC II, vertical axis, 14% of variance. The shape variability represented by each principal component is indicated by the wireframe configurations at each extreme. (Blumenfeld et al., 2005)

Slide22: 

Principal Components Analysis (PCA): Right-side parasagittal contour PCA of the right-side contour profiles for all specimens included in this study. PC I, horizontal axis, 74% of variance; PC II, vertical axis, 13% of variance. The shape variability represented by each principal component is indicated by the wireframe configurations at each extreme. (Blumenfeld et al., 2005)

Slide23: 

Advantages in using the ShapeCam system: portable can analyze digital images repeatedly (minimizes travel, saves time and money) reduces frequency with which specimens are handled (reduces damage) rapid method of data acquisition The End