PLB143 - Lecture 12: How was agriculture disseminated? The case of Europe

How was agriculture disseminated? The case of Europe © Paul Gepts 1995-2008

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PLB143: Readings - Lecture 12 Required reading: Barbujani G, Pilastro A (2003) Genetic evidence on origin anddispersal of human populations speaking languages of the Nostratic macrofamily. Proc. Nat. Acad. Sci. USA 90: 4670-4673 UCD Access only (Kerberos password) Suggested readings: Ammerman AJ, Cavalli-Sforza LL (1984) The Neolithic transitionand the genetics ofpopulations in Europe. Princeton Univ. Press, Princeton, NJ: Chapter 7: pp. 109-132 UCD Access only (Kerberos password) Sokal RR (1991) The continental population structure of Europe. Ann. Rev. Anthropol.20: 119-140. Sokal RR, Oden NL, Wilson C (1991) Genetic evidence for the spread of agriculturein Europe by demic diffusion. Nature 351: 143-145. Piazza A (1993) Who are the Europeans? Science 260: 1767-1769 Fowler B (2000) The Iceman. Random House GEO - Der Man aus der Steinzeit: http://www.geo.de/themen/historie/oetzi/ Nova Online: The Iceman's last meal: http://www.pbs.org/wgbh/nova/icemummies/iceman.html Presentation slides Pdf version (2008 version)

Disssemination of crops Modes Human migration Cultural exchange Trade Warfare Scientific exploration Introduction into Europe From the Near East; 9,000 BP Why Europe? Substantial amount of data available archaeological data: dated (14C) plant remains human population data anthropometry osteometric: e.g. craniometry dermatoglyph cultural: e.g., language genetic: genotypic!

Archaeological data for the spread of agriculture into Europe Dating of plant remains domesticated elsewhere emmer wheat barley local domesticates: oat Material culture: ceramic: e.g., Bandkeramik (Linear Pottery) in Central Europe: settlement patterns: near water and arable land, i.e. most favorable sites: houses: rectangular shape; timber framework and earth-covered walls: Example: Map of an excavation in Vaihingen, Germany : notice the rectangular shapes representing the foundations of several houses; social organization sedentism Results: Spread of agriculture started in 9,000 BP; complete in 5,000 BP: linear progression of agriculture into Europe: 1 km/yr: Some related sites of interest Bandkeramik archaeological site in Vaihingen, Baden-Würtemberg, Germany Archaeological research at Oslonski, Poland The Neolithic Mosaic on the NorthEuropean Plain	Examples of Bandkeramik Settlements Aerial photo of an excavation showing the rectangular house shape ,

The "Iceman" or "Oetzi," an early agricultural inhabitant of Europe Discovered in 1991 in the Alps on the border of Italy and Austria Dated to 5100-5350 yrs BP 1.60 m; 40-45 years Clothing and gear! See drawings to the right Reconstruction in full gear and with accessories from http://www.geo.de/themen/historie/oetzi/ Agricultural context of the Iceman (Fowler 2000) Last meal main ingredient: einkorn, based on remains in colon charcoal: einkorn used to make "bread" (cracker-like), baked over open fire pollen of hop hornbeam tree: March-June, south of mountains Also einkorn grains found in clothing	Oetzi body (from Fowler 2000) Successive layers of clothing , , and (from Fowler 2000)

What was the mechanism of spread of agriculture into Europe? Theoretically, two extreme types of diffusion: Cultural diffusion: i.e. techniques , ideas, and materials are passed along and learned no movement of people certain continuity in culture between mesolithic and neolithic stronger cultural differentiation Demic diffusion: i.e. techniques travel with people population growth and short-distance migration (i.e. not colonization) migrants would maintain continuity in social and cultural context Which type of diffusion was involved here? Population growth associated with the introduction of agriculture Population densities: hunter-gatherers (Pacific Northwest): 0.01-1/sq. km agriculturalists: 3 -300/sq. km Same life expectancy (= death rate) + increased birth rate (child spacing from 4yrs to 2.5 yrs. Why? sedentism labor

Model for population growth "Wave-of-advance" (Fisher 1936) Two major factors: population growth: a: e.g., 2% limited migratory activity: M: relocation to adjacent, unoccupied land: hunters-gatherers (e.g., Pygmies): average distance between known sites: male: 88km; female: 57 km farmers: average mating distance: 12-13 km Generates "wave": population growth rate is largest at front of the wave population growth rate is 0 behind wave: carrying capacity Prediction for gene frequencies: cultural model: no change demic model: replacement of alleles mixed model: gradient of allele frequencies Interactions between hunter- gatherers and farmers: acculturation = gene flow warfare disease mutualism	Wave of advance generated by population growth Population growth rates
Analyses of genetic data Types: 26 genetic marker systems red cell antigens: e.g., ABO plasma proteins enzymes: e.g., PGM HLA alleles: immunoglobulins Locations: 33-870; total of 3,373. Individuals/location: 50 -->1,000s Statistical analysis: "ordination": e.g., Principal Component Analysis reduce number of dimensions limited number of dimensions, i.e. principal components decreasing order of variance accounted for by principal components Results of Principal Component Analyses Outliers: Lapps: fron N. Siberian people (Samoyeds); Uralic family language Basques and Irish: direct descendants of earliest post-Neanderthal occupants in Europe; Paleolithic:40,000 BP (see cave art!) Sardinians: influx from Paleolithic, Neolithic farmers, Phoenicians, Carthaginians,Greeks, etc. Overall similarity to Lebanese Major trends: First principal component: S. E. <--> N.W. gradient corresponding presumably to the introduction of agriculture Second principal component: N. <--> S. or S.W. <--> N.W. gradient: adaptation to temperatureor partition between Indo-European and Uralic languages? Third principal component: E. <--> W. gradient: "Kurgan" culture originating in Eurasian steppes	HLA allele frequencies Outliers of principal component analysis Principal component analyses
Origin of the Indo-Europeans in Europe? First or third component Renfrew Near-East --> Greece (8,500 BC) --> rest of Europe Gimbutas "Kurgan": russian for barrow (cart) southern steppes of Ukraine (e.g.,Yamna culture) --> eastern Europe (Danube, Carpathian bassin) (3,300 BC) linguistic arguments & archaeological: horseback riding, wheeled vehicles
Four language family putatively descended from an original language, Nostratic, spoken in the Near Eastern Center of origin. Four major migrations from this center, each giving rise to a different language family. Correlated with genetic data: Indo-European: towards Northwest (Europe) and Southwest (Iran, Pakistan, and India) Afro-Asiatic: Arabian peninsula and northern Africa Altaic: central Asia Elamo-Dravidian: towards Southwest (same as Indo-European but earlier)	Putative relationship between agricultural migrations and language families

Computer simulation study Divide European territory into rectangular lattice; determine population or genefrequencies in each cell of the lattice First stage: 11,000-8,000 BC: Hunter-gatherers: low density: 0.02/sq.km genetic drift (chance) + some migration no general large scale patterns Second stage: 8,000-4,000 BC: Spread of early farming from Near East: 120 generations to reach N.W. Europe S.E. --> N.W. gradient in gene frequencies Third stage: 4,000-0 BC: Subsequent demic events Two demic events simulated (see PCA) Overall gradient established in second stage is maintained Fourth stage: 0-2,000 AD Ongoing evolution No other major migration but reciprocal shorter-distance migration between adjacentregions Overall analysis with model: recreates S.E. gradient <--> N.W.	First stage: Hunter-gatherers Second stage: Early spread Overall analysis

Conclusion Striking persistence of gene frequency patterns resulting from ancient events Spread of agriculture in Europe: demic diffusion + admixture between hunter-gatherersand agriculturalists Ammerman and Cavalli-Sforza (1984): " In the case of evolutionary ... reconstructions,we are not dealing with phenomena that are occurring under controlled conditions and that can be repeated at will in the laboratory... . Confidence in reconstructions is built by the development of multiple lines of evidence that generate independent support for a particular interpretation. Ultimately, it is the growth of new evidence in individual fields and the creation of expectations for findings in other fields that generate a dense network for evaluating a reconstructive hypothesis. "