{{Short description|Demographic concept}} [[File:Genetic matrilineal distances between European Neolithic Linear Pottery Culture populations (5,500–4,900 calibrated BC) and modern Western Eurasian populations.jpg|thumb|upright=1.5|An example of Demic diffusion: ancient European Neolithic farmers were genetically closest to ancient Near-Eastern/Anatolian populations. Genetic matrilineal distances between European Neolithic Linear Pottery Culture populations (5,500–4,900 calibrated BC) and modern Western Eurasian populations. The coloring indicates the degree of similarity of the modern local population(s) with the Neolithic sample set: short distances (greatest similarity) are marked by dark green and long distances (greatest dissimilarity) by orange, with fainter colors in between the extremes. Note that green intervals are scaled by genetic distance values of 0.02, with increasingly larger intervals towards the "orange" end of the scale.<ref>{{cite journal |last1=Consortium |first1=the Genographic |last2=Cooper |first2=Alan |title=Ancient DNA from European Early Neolithic Farmers Reveals Their Near Eastern Affinities |journal=PLOS Biology |date=9 November 2010 |volume=8 |issue=11 |article-number=e1000536 |doi=10.1371/journal.pbio.1000536 |language=en |issn=1545-7885|pmc=2976717 |pmid=21085689 |doi-access=free }}</ref>]]
In demography, '''demic diffusion''', as opposed to ''trans-cultural diffusion'', is a model of human migration developed by Luigi Luca Cavalli-Sforza. It originally includes three phases: (1) population growth, prompted by new available resources as in the case of early farmers, and/or other technological developments; (2) a dispersal into regions with lower population density; (3) a limited initial admixture with the people encountered in the process. It may account for displacing, replacing, or intermixing with an existing population, such as has been suggested for the spread of agriculture across Neolithic Europe and several other ''Landnahme'' events.
==Evidence== Theoretical work by Cavalli-Sforza showed that if admixture between expanding farmers and previously-resident groups of hunters and gatherers was not immediate, the process would result in the establishment of broad genetic gradients. Because broad gradients, spanning much of Europe from southeast to northwest, were identified in empirical genetic studies by Cavalli-Sforza, Robert R. Sokal, Guido Barbujani, Lounès Chikhi and others, it seemed likely that the spread of agriculture into Europe occurred by the expansion and the spread of agriculturists, who possibly originated in the Fertile Crescent of the Near East.<ref>Chicki, L; Nichols, RA; Barbujani, G; Beaumont, MA. 2002. Y genetic data support the Neolithic demic diffusion model. ''Proc. Natl. Acad. Sci''. 99(17): 11008-11013.</ref> That is referred to as the Neolithic demic diffusion model.
Craniometric<ref>C. Loring Brace, Noriko Seguchi, Conrad B. Quintyn, Sherry C. Fox, A. Russell Nelson, Sotiris K. Manolis, and Pan Qifeng, "The questionable contribution of the Neolithic and the Bronze Age to European craniofacial form," in Proceedings of the National Academy of Sciences of the United States (Jan. 3, 2006). Vol. 103, No. 1, pp. 242-247. [http://www.pnas.org/content/103/1/242.full] {{doi|10.1073/pnas.0509801102}}</ref><ref>F. X. Ricaut, M. Waelkens, "Cranial Discrete Traits in a Byzantine Population and Eastern Mediterranean Population Movements," in Human Biology, Wayne State University Press (Aug. 2008). Vol. 80, Issue 5, pp. 535-564. [http://www.bioone.org/doi/abs/10.3378/1534-6617-80.5.535] {{doi|10.3378/1534-6617-80.5.535}}</ref> and archaeological<ref>M. Zvelebil, in ''Hunters in Transition: Mesolithic Societies and the Transition to Farming,'' M. Zvelebil (editor), Cambridge University Press: Cambridge, UK (1986) pp. 5-15, 167–188.</ref><ref>P. Bellwood, ''First Farmers: The Origins of Agricultural Societies,'' Blackwell: Malden, MA (2005).</ref><ref>M. Dokládal, J. Brožek, ''Curr. Anthropol. 2'' (1961) pp. 455–477.</ref><ref>O. Bar-Yosef, ''Evol. Anthropol. 6'' (1998) pp. 159–177.</ref><ref>M. Zvelebil, ''Antiquity 63'' (1989) pp. 379–383.</ref> studies have also arrived at the same conclusion.
==References== {{Reflist}}
==External links== * [https://web.archive.org/web/20070311042315/http://mbe.oxfordjournals.org/cgi/content/full/21/7/1361/T03 Estimating the Impact of Prehistoric Admixture on the Genome of Europeans, Dupanloup et al., 2004] *[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1181965/ Origin, Diffusion, and Differentiation of Y-Chromosome Haplogroups E and J: Inferences on the Neolithization of Europe and Later Migratory Events in the Mediterranean Area, 2004] * [http://www.pnas.org/cgi/reprint/99/17/11008 Y genetic data support the Neolithic demic diffusion model, Chikhi 2002.] * [http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1715849&blobtype=pdf Paleolithic and Neolithic lineages in the European mitochondrial gene pool, Cavalli-Sforza 1997.]{{dead link|date=July 2025|bot=medic}}{{cbignore|bot=medic}} * [http://www.pnas.org/cgi/reprint/95/15/9053 Clines of nuclear DNA markers suggest a largely Neolithic ancestry of the European gene, Chikhi 1997.]
Category:Demography