Defining behavioral modernity in the context of neandertal and anatomically modern human populations

Annual Review of Anthropology

Volumn 39, Issue , 2010, Pages 437-452

  Nowell, April ^a  

^a UNIVERSITY OF VICTORIA   (Canada)

Author keywords

Aurignacian; Ch telperronian; cognition; demography

Indexed keywords

ANATOMY; ANTHROPOLOGY; COGNITION; DEMOGRAPHY; MODERNITY; NEANDERTHAL;

EID: 77957992662     PISSN: 00846570     EISSN: None     Source Type: Book Series    
DOI: 10.1146/annurev.anthro.012809.105113     Document Type: Article

References (142)

1. Ambrose S. 1998. Late Pleistocene human population bottlenecks, volcanic winter, and differentiation of modern humans. J. Hum. Evol. 34:623-51
2. Bailey S, Hublin J-J. 2006a. Dental remains from the Grotte du Renne at Arcy-Sur-Cure (Yonne). J. Hum. Evol. 50:485-508
3. Bailey SE, Hublin J-J. 2006b. Did Neanderthals make the Châtelperronian assemblage from La Grotte du Renne (Arcy-sur-Cure, France)? In Neanderthals Revisited: New Approaches and Perspectives (Vertebrate Paleobiology and Paleoanthropology Ser.), ed. K Havarti, T Harrison, pp. 191-209. New York: Springer
4. Balme J, Davidson I, MacDonald J, Stern N, Veth P. 2009. Symbolic behavior and peopling of the southern arc route to Australia. Quaternary Int. 202:59-68
5. Barham L. 2007. Modern is as modern does? Technological trends and thresholds in the south-central African record. See Mellars et al. 2007a, pp. 165-76
6. Barham L, Mitchell P. 2008. The First Africans: African Archaeology From the Earliest Tool-Makers to Most Recent Foragers. Cambridge: Cambridge Univ. Press
7. Bar-Yosef O. 1998. On the nature of transitions: the Middle to Upper Paleolithic and the Neolithic revolution. Cambr. Archaeol. J. 8:141-63
8. Bar-Yosef O. 2002. The Upper Paleolithic revolution. Annu. Rev. Anthropol. 31:395-417
9. Bar-Yosef O. 2006. Neandertals and modern humans: a different interpretation. See Conard 2006b, pp. 467-82
10. Bar-Yosef O, Kuhn S. 1999. The big deal about blades: laminar technologies and human evolution. Am. Anthropol. 101:322-38
11. Bar-Yosef Mayer D, Vandermeersch B, Bar-Yosef O. 2009. Shells and ochre in Middle Paleolithic Qafzeh Cave, Israel: indications for modern behavior. J. Hum. Evol. 56:307-14
12. Bickerton D. 2007. Did syntax trigger the human revolution? See Mellars et al. 2007a, pp. 99-105
13. Binford LR. 1985. Human ancestors: changing views of their behavior. J. Anthropol. Archaeol. 4:292-327
14. Binford LR. 1989. Isolating the transition to cultural adaptations: an organizational approach. In Emergence of Modern Humans: Biocultural Adaptations in the Late Pleistocene, ed. E Trinkaus, pp. 18-41. Cambridge: Cambridge Univ. Press
15. Bordes J-G. 2003. Lithic taphonomy of the Châtelperronian/ Aurignacian interstratifications in Roc de Combe and Le Piage (Lot, France). In The Chronology of the Aurignacian and of the Transitional Technocomplexes: Dating, Stratigraphies, Cultural Implications, ed J Zilhão, F d'Errico, pp. 223-44. Lisbon: Instit. Portuguese Arqueol.
16. Bouzouggar A, Barton N, Vanhaeren M, d'Errico F, Collcutt S, et al. 2007. 82, 000-year-old shell beads from North Africa and implications for the origins of modern human behavior. Proc. Natl. Acad. Sci. USA 104:9964-69
17. Bower J. 2005. On 'Modern Behavior' and the evolution of human intelligence. Curr. Anthropol. 46 (1):121-22
18. Brumm A, Moore M. 2005. Symbolic revolutions and the Australian archaeological record. Cambr. Archaeol. J. 15:157-75
19. Byers M. 1994. Symboling and the Middle to Upper Paleolithic transition: a theoretical and methodological critique. Curr. Anthropol. 35:369-99
20. Camps M, Chauhan P, eds. 2009. Sourcebook of Paleolithic Transitions. New York: Springer
21. Chase PG. 1999. Symbolism as reference and symbolism as culture. In The Evolution of Culture: An Interdisciplinary View, ed. RIM Dunbar, C Knight, C Power, pp. 34-99. Edinburgh: Edinburgh Univ. Press
22. Chase PG. 2001. "Symbolism" is two different phenomena: implications for archaeology and paleontology. In Humanity From African Naissance to Coming Millennia, Colloquia in Human Biology and Paleoanthropology, ed. PV Tobias, MA Raath, J Moggi-Cecchi, GA Doyle, pp. 199-212. Florence: Firenze Univ. Press
23. Chase PG. 2003. Comment on "The origin of modern behavior: a review and critique of models and test implications" by Henshilwood and Marean. Curr. Anthropol. 44 (5):637
24. Chase PG. 2006. The Emergence of Culture: The Evolution of a Uniquely Human Way of Life. New York: Springer
25. Chase PG. 2007. The significance of acculturation depends on the meaning of culture. See Mellars et al. 2007a, pp. 55-66
26. Chase PG, Dibble HL. 1992. Scientific archaeology and the origins of symbolism: a reply to Bednarik. Cambridge Archaeol. J. 2:43-51
27. Chase P, Nowell A. 1998. Taphonomy of a suggested Middle Paleolithic bone flute from Slovenia. Curr. Anthropol. 39 (4):549-53
28. Clark GA. 2002. Neandertal archaeology-implications for our origins. Am. Anthropol. 104:50-67
29. Clark GA, Riel-Salvatore J. 2009. What's in a name? Observations on the compositional integrity of the Aurignacian. In The Mediterranean From 50, 000-25, 000 BP. Turning Points and New Directions, ed M Camps, C Szmidt, pp. 323-38. Oxford: Oxbow Books
30. Conard N. 2006a. Changing views of the relationship between Neandertals and modern humans. See Conard 2006b, pp. 5-20
31. Conard N, ed. 2006b. When Neandertals and Modern Humans Met. Tübingen: Kerns Verlag
32. Conkey M. 1997. Beyond art and between the caves: thinking about context in the interpretive process. In Beyond Art: Pleistocene Image and Symbol, ed. M Conkey, O Soffer, D Stratmann, NG Jablonski, pp. 343-68. San Francisco: Mem. Calif. Acad. Sci.
33. Coolidge F, Wynn T. 2004. A cognitive and neuropsychological perspective on the Châtelperronian. J. Anthropol. Res. 60:55-73
34. Coolidge F, Wynn T. 2005. Working memory, its executive functions, and the emergence of modern thinking. Cambr. Archaeol. J. 15 (1):5-26
35. Davidson I. 1990. Bilzingsleben and early marking. Rock Art Res. 7:52-56
36. Davidson I. 2010. The colonization of Australia and its adjacent islands and the evolution of modern cognition. Curr. Anthropol. 51 (Suppl. 1): S177-89
37. Davidson I, Noble W. 1989. The archaeology of perception: traces of depiction and language. Curr. Anthropol. 30 (2):125-56
38. Davidson I, Noble W. 1992. Why the first colonization of the Australian region is the earliest evidence of modern human behavior. Perspect. Hum. Biol. Archaeol. Oceania 27:113-19
39. Davidson I, Noble W. 1993. Tools and language in human evolution. In Tools, Language and Cognition in Human Evolution, ed. KR Gibson, T Ingold, pp. 363-88. Cambridge: Cambridge Univ. Press
40. Deacon HJ, Wurz S. 2001. Middle Pleistocene populations of southern Africa and the emergence of modern behavior. In Human Roots: Africa and Asia in the Middle Pleistocene, ed. L Barham, K Robson-Brown, pp. 55-63. Bristol: West. Acad. Spec. Press
41. d'Errico F. 2003. The invisible frontier. A multiple species model for the origin of behavioral modernity. Evol. Anthropol. 12:188-202
42. d'Errico F. 2007. The origin of humanity and modern cultures: archaeology's view. Diogenes 54:122-33
43. d'Errico F, Henshilwood C, Lawson G, Vanhaeren M, Tillier A-M, et al. 2003. Archaeological evidence for the emergence of language, symbolism, and music-an alternative multidisciplinary perspective. J. World Prehist. 17 (1):1-70
44. d'Errico F, Henshilwood C, Vanhaeren M, van Niekerk K. 2005. Nassarius kraussianus shell beads from Blombos Cave: evidence for symbolic behavior in the Middle Stone Age. J. Hum. Evol. 48:3-24
45. d'Errico F, Nowell A. 2000. Origins of symboling in the Near East: a new look at the Berekhat Ram figurine. Cambr. Archaeol. J. 10 (1):123-67
46. d'Errico F, Vanhaeren M. 2007. Evolution or revolution? New evidence for the origins of symbolic behavior in and out of Africa. See Mellars et al. 2007a, pp. 275-86
47. d'Errico F, Vanhaeren M, Barton N, Bouzouggar A, Mienis H, et al. 2009. Additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa. Proc. Natl. Acad. Sci. USA 106:16051-56
48. d'Errico F, Villa P. 1997. Holes and grooves. The contribution of microscopy and taphonomy to the problem of art origins. J. Hum. Evol. 33:1-31
49. d'Errico F, Zilhão J, Julien M, Baffier D, Pelegrin J. 1998. Neandertal acculturation in Western Europe? A critical review of the evidence and its interpretation. Curr. Anthropol. 39: S1-44
50. Donald M. 1991. Origin of the Modern Mind: Three Stages in the Evolution of Culture and Cognition. Cambridge, MA: Harvard Univ. Press
51. Donald M. 2001. A Mind So Rare: The Evolution of Human Consciousness. New York: Norton
52. Gamble C. 1999. Paleolithic Societies of Europe. Cambridge: Cambridge Univ. Press
53. Greene K. 1999. V. Gordon Childe and the vocabulary of revolutionary change. Antiquity 73:97-109
54. Habgood PJ, Franklin NR. 2008. The revolution that didn't arrive: a review of Pleistocene Sahul. J. Hum. Evol. 55 (2):187-222
55. Harrold F. 2007. On the fate of the Neandertals and the Middle-Upper Paleolithic transition in Western Europe. In New Approaches to the Study of Early Upper Paleolithic 'Transitional' Industries in Western Eurasia: Transitions Great and Small, ed. J Riel-Salvatore, GA Clark, pp. 19-32. Oxford: Archaeopress
56. Harrold F. 2009. Historical perspectives on the European transition from Middle to Upper Paleolithic. See Camps & Chauhan 2009, pp. 283-99
57. Hayden B. 1993. Cultural capacities of Neandertals: a review and re-evaluation. J. Hum. Evol. 24:113-46
58. Henry DO, Hietala HJ, Rosen AM, Demidenko YE, Usik V, Armagan TL. 2004. Human behavioral organization in the Middle Paleolithic: Were Neanderthals different? Am. Anthropol. 106:17-31
59. Henshilwood CS. 2007. Fully symbolic sapiens behavior: innovation in the Middle Stone Age at Blombos Cave, South Africa. See Mellars et al. 2007a, pp. 123-32
60. Henshilwood CS, Marean C. 2003. The origin of modern human behavior. Curr. Anthropol. 44:627-51
61. Henshilwood CS, d'Errico F, Watts I. 2009. Engraved ochres from the Middle Stone Age levels at Blombos Cave, South Africa. J. Hum. Evol. 57:27-47
62. Hill K, Barton M, Hurtado AM. 2009. The emergence of human uniqueness: characters underlying behavioral modernity. Evol. Anthropol. 18:187-200
63. Hockett B, Haws JA. 2005. Nutritional ecology and the human demography of Neandertal extinction. Quaternary Int. 137:21-34
64. Holdaway S, Cosgrove R. 1997. The archaeological attributes of behaviour: differenceor variability? Endeavour 21 (2):66-71
65. Holloway R, Broadfield DC, Yuan M. 2004. The Human Fossil Record, Volume Three: Brain Endocasts. The Paleoneurological Evidence. New Jersey: Wiley-Liss
66. Hopkinson T. 2010. The transmission of technological skills in the Paleolithic: insights from metapopulation ecology. In Investigating Archaeological Cultures: Cultural Transmission and Material Culture Variability, ed. B Roberts, M Vander Linden. New York: Springer. In press
67. Hovers E, Belfer-Cohen A. 2006. Now you see it, now you don't-modern human behavior in the Middle Paleolithic. In Transitions Before The Transition: Evolution and Stability in the Middle Paleolithic and Middle Stone Age, ed E Hovers, SL Kuhn, pp 205-304. New York: Springer
68. Hublin J-J, Bailey SE. 2006. Revisiting the last Neandertals. See Conard 2006b, pp. 105-28
69. Hublin J-J, Spoor F, Braun M, Zonneveld F, Condemi S. 1996. A late Neanderthal associated with Upper Paleolithic artifacts. Nature 381:224-26
70. Karkanas P, Rigaud J-P, Simek JF, Albert RM, Weiner S. 2002. Ash, bones and guano: study of the minerals and phytolithis in the sediments of Grotte XVI, Dordogne, France. J. Archaeol. Sci. 29:721-32
71. Klein R. 1989. Biological and behavioral perspectives on modern human origins in southern Africa. In The Human Revolution: Behavioral and Biological Perspectives on the Origins of Modern Humans, ed. P Mellars, CB Stringer, pp. 529-46. Edinburgh: Edinburgh Univ. Press
72. Klein RG. 1995. Anatomy, behavior, and modern human origins. J. World Prehist. 9:167-98
73. Klein RG. 2000. Archaeology and the evolution of human behavior. Evol. Anthropol. 9:17-36
74. Klein RG. 2001. Southern Africa and modern human origins. J. Anthropol. Res. 57:1-16
75. Klein RG. 2003. Whither the Neandertals? Science 299:1525-27
76. Klein RG. 2008. Out of Africa and the evolution of human behavior. Evol. Anthropol. 17:267-81
77. Koller J, Baumer U, Mania D. 2001. High-tech in the Middle Paleolithic: Neandertal manufactured pitch identified. Eur. J. Archaeol. 4:385-97
78. Kuhn S, Stiner M. 2007a. Body ornamentation as information technology: towards an understanding of the significance of early beads. See Mellars et al. 2007a, pp. 45-54
79. Kuhn S, Stiner M. 2007b. Paleolithic ornaments: implications for cognition, demography and identity. Diogenes 54:40-48
80. Lahr MM. 1996. The Evolution of Modern Human Diversity. Cambridge: Cambridge Univ. Press
81. Lahr MM, Foley R. 1998. Towards a theory of modern human origins: geography, demography and diversity in recent human evolution. Yearbk. Phys. Anthropol. 41:137-76
82. Lewis-Williams D. 2002. The Mind in the Cave. London: Thames & Hudson
83. Lieberman P. 2007. The evolution of human speech: its anatomical and neural bases. Curr. Anthropol. 48:39-66
84. Marean CW. 2007. Heading north: an Africanist perspective on the replacement of Neanderthals by modern humans. See Mellars et al. 2007a, pp. 367-79
85. Marean CW, Bar-Matthews M, Bernatchez J, Fisher E, Goldberg P, et al. 2007. Early human use of marine resources and pigment in South Africa during the Middle Pleistocene. Nature 449:905-8
86. McBrearty S. 2007. Down with the revolution. See Mellars et al. 2007a, pp. 133-51
87. McBrearty S, Brooks A. 2000. The revolution that wasn't: a new interpretation of the origin of modern behavior. J. Hum. Evol. 39:453-563
88. Mellars P. 1973. The character of the Middle-upper Paleolithic transition in south-west France. In The Explanation of Culture-Change, ed. C Renfrew, pp. 255-76. London: Duckworth
89. Mellars P. 1989. Technological changes at the Middle-Upper Paleolithic transition: economics, social and cognitive perspectives. See Mellars & Stringer 1989, pp. 338-65
90. Mellars P. 1990. The Emergence of Modern Humans: An Archaeological Perspective. Ithica: Cornell Univ. Press
91. Mellars P. 1996. The Neanderthal Legacy: An archaeological Perspective from Western Europe. Princeton: Princeton Univ. Press
92. Mellars P. 2005. The impossible coincidence: a single species model for the origins of modern human behavior in Europe. Evol. Anthropol. 14:12-27
93. Mellars P. 2006a. A new radiocarbon revolution and the dispersal of modern humans in Eurasia. Nature 439:931-35
94. Mellars P. 2006b. Archaeology and the dispersal of modern humans in Europe: deconstructing the Aurignacian. Evol. Anthropol. 15:167-82
95. Mellars P. 2007. Rethinking the human revolution: Eurasian and African perspectives. See Mellars et al. 2007a, pp. 1-14
96. Mellars P, Boyle K, Bar-Yosef O, Stringer C, eds. 2007a. Rethinking the Human Revolution. Cambridge: MacDonald Institute
97. Mellars P, Gravina B, Bronk Ramsey C. 2007b. Confirmation of the Neandertal/modern human interstratifcation at the Châtelperronian type-site. Proc. Natil. Acad. Sci. USA 104:3657-62
98. Mellars P, Otte M, Straus L, Zilhão J, d'Errico F. 1999. California forum on theory in anthropology: the Neandertal problem, continued. Curr. Anthropol. 40:341-64
99. Mellars P, Stringer C, eds. 1989. The Human Revolution. Edinburgh: Univ. Edinburgh Press
100. Mithen S. 1996. The Prehistory of the Mind. London: Thames & Hudson
101. Mithen S. 2005. The Singing Neanderthals. London: Weidenfield and Nicolson
102. Noble W, Davidson I. 1991. The evolutionary emergence of modern human behavior: language and its archaeology. Man 26:223-53
103. Noble W, Davidson I. 1996. Human Evolution, Language and Mind: A Psychological and Archaeological Inquiry. Cambridge: Cambridge Univ. Press
104. Norton CJ, Jin JJH. 2009. The evolution of modern human behavior in East Asia: current perspectives. Evol. Anthropol. 18:247-60
105. Nowell A, d'Errico F. 2007. The art of taphonomy and the taphonomy of art. J. Archaeol. Method Theory 14 (1):1-26
106. Nowell A, White M. 2010. Growing up in the Middle Pleistocene: life history strategies and their relationship to Acheulian industries. In Stone Tools and the Evolution of Human Cognition, ed. A Nowell, I Davidson, pp. 67-82. Boulder: Univ. Press Col.
107. O'Connell JF. 2006. How did modern humans displace Neandertals? Insights from hunter-gatherer ethnography and archaeology. See Conard 2006b, pp. 43-64
108. O'Connell JF, Allen J. 2007. Pre-LGM Sahul (Pleistocene Australia-New Guinea) and the archaeology of early modern humans. See Mellars et al. 2007a, pp. 395-410
109. Olszewski D, Dibble HL. 1994. The Zagros Aurignacian. Curr. Anthropol. 35 (1):68-75
110. Parkington J. 2001. Milestones: the impact of systematic exploitation of marine foods on human evolution. In Humanity From African Naissance to Coming Millennia, Colloquia in Human Biology and Paleoanthropology, ed. PV Tobias, MA Raath, J Moggi-Cecchi, GA Doyle, pp. 327-36. Florence: Firenze Univ. Press
111. Pettitt P, Pike AWG. 2001. Blind in a cloud of data: problems with the chronology of Neanderthal extinction and modern human expansion. Antiquity 75:415-20
112. Powell A, Shennan S, Thomas MG. 2009. Late Pleistocene demography and the appearance of modern human behavior. Science 324 (5932):1298-301
113. Riel-Salvatore J, Clark GA. 2001. Grave markers: Middle and Early Upper Paleolithic burials and the use of chronotypology in contemporary Paleolithic research. Curr. Anthropol. 42:449-79
114. Reimer PJ, Baillie MGL, Bard E, Bayliss A, Beck JW, et al. 2010. IntCal09 and Marine09 radiocarbon age calibration curves, 0-50, 000 years cal BP. Radiocarbon 51:1111-50
115. Rossano M. 2009. Ritual behavior and the origins of modern cognition. Cambr. Archaeol. J. 19 (2):243-56
116. Shea J. 2003. Neandertals, competition and the origin of modern human behaviorinthe Levant. Evol. Anthropol. 12:173-87
117. Shea J. 2008. Transitions or turnovers? Climatically forced extinctions of Homo sapiens and Neandertals in the east Mediterranean Levant. Quaternary Sci. Rev. 27 (23-24): 2253-70
118. Shennan S. 2001. Demography and cultural innovation: a model and its implications for the emergence of modern human culture. Cambr. Archaeol. J. 11:5-16
119. Soffer O. 2009. Defining modernity, establishing rubicons, imagining the other-and the Neanderthal enigma. See Camps & Chauhan 2009, pp. 43-64
120. Soriano S, Villa P, Wadley L. 2007. Blade technology and tool forms in the Middle Stone Age of South Africa: the Howiesons Poort and post-Howiesons Poort at Rose Cottage Cave. J. Archaeol. Sci. 34:681-703
121. Spikins P. 2009. Autism, the integrations of 'difference' and the origins of modern human behavior. Cambr. Archaeol. J. 19 (2):179-201
122. Straus LG. 2009. Has the notion of 'transitions' in Paleolithic prehistory outlived its usefulness? The European record in wider context. See Camps & Chauhan 2009, pp. 3-18
123. Stringer CB. 2006. The Neanderthal-H. sapiens interface in Eurasia. In Neanderthals Revisited: New Approaches and Perspectives, ed. E Delson, RDE McPhee, pp. 315-23. New York: Springer
124. Stringer CB, Gamble C. 1993. In Search of the Neandertals. New York: Thames & Hudson
125. Texier P-J, Porraz G, Parkington J, Rigaud J-P, Poggenpoel C, et al. 2010. A Howiesons Poort tradition of engraving ostrich eggshell containers dated to 60, 000 years ago at Diepkloof Rock Shelter, South Africa. Proc. Natl. Acad. Sci. USA 107 (14):6180-85
126. Trinkaus E. 2005. Early modern humans. Annu. Rev. Anthropol. 34:207-30
127. Unger PS, Grine FE, Teaford MF. 2006. Diet in early Homo: a review of the evidence and a new model of adaptive versatility. Annu. Rev. Anthropol. 35:209-28
128. Vanhaeren M, d'Errico F, Stringer C, James SL, Todd JA, Mienis HK. 2006. Middle Paleolithic shell beads in Israel and Algeria. Science 12:1785-88
129. Wadley L. 2001. What is cultural modernity? A general view and a South African perspective from Rose Cottage Cave. Cambr. Archaeol. J. 11 (2):201-21
130. Weniger G-C. 2006. Neandertals and early modern humans-human contacts on the borderline of archaeological visibility. See Conard 2006b, pp. 21-32
131. White R. 1982. Rethinking the Middle/Upper Paleolithic transition. Curr. Anthropol. 23 (2):169-92
132. White R. 1992. Beyond art: toward an understanding of the origins of material representation in Europe. Annu. Rev. Anthropol. 21:537-64
133. White R. 2003. Prehistoric Art: The Symbolic Journey of Humankind. New York: Abrams
134. White R. 2007. Systems of personal ornamentation in the early Upper Paleolithic. See Mellars et al. 2007a, pp. 287-303
135. White TD, Asfaw B, DeGusta D, Tilbert H, Richards GD, et al. 2003. Pleistocene Homo sapiens from Middle Awash, Ethiopia. Nature 423:742-47
136. Wolpoff M, Mannnheim B, Mann A, Hawkes J, Caspari R, et al. 2004. Why not the Neandertals? World Archaeol. 36:527-46
137. Wynn T, Coolidge F. 2004. The expert Neandertal mind. J. Hum. Evol. 46:467-87
138. Wynn T, Coolidge F. 2007. Did a small but significant enhancement in working memory capacity power the evolution of modern thinking? See Mellars et al. 2007a, pp. 79-90
139. Zilhão J. 2006. Neandertals and moderns mixed, and it matters. Evol. Anthropol. 15:183-95
140. Zilhão J. 2007. The emergence of ornaments and art: an archaeological perspective on the origins of behavioral modernity. J. Archaeol. Res. 15:1-54
141. Zilhão J, Angelucci D, Badal-García E, d'Errico F, Daniel F, et al. 2010. Symbolic use of marine shells and mineral pigments by Iberian Neandertals. Proc. Natl. Acad. Sci. USA 107 (3):1023-28
142. Zilhão J, d'Errico F, Bordes J-G, Lenoble A, Texier J-P, Rigaud J-P. 2006. Analysis of Aurignacian interstratifications at the Châtelperronian type-site and implications for the behavioral modernity of Neandertals. Proc. Natl. Acad. Sci. USA 103:12643-48