Editing Levallois technique (section)

==Evolution==
[[File:Stone Core for Making Blades - Boqer Tachtit, Negev, circa 40000 BP (detail).jpg|thumb|{{center|The [[Prepared-core technique]] starts by shaping a flint stone core for making blades (reassembled from blades for illustration purposes), Boqer Tachtit, Negev, [[Israel]], circa 40000 BP.}}]]

The distinctive forms of the flakes were originally thought to indicate a wide-ranging Levallois [[archaeological culture|culture]] resulting from the expansion of archaic ''Homo sapiens'' out of Africa. However, the wide geographical and temporal spread of the technique has rendered this interpretation obsolete.{{further|Prepared-core technique}} Adler ''et al.'' further argue that Levallois technology evolved independently in different populations and thus cannot be used as a reliable indicator of Paleolithic human population change and expansion.<ref>{{cite journal | last1 = Adler | first1 = D. S. |display-authors=etal  | year = 2014 | title = Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus | url = https://www.science.org/doi/abs/10.1126/science.1256484 | journal = Science | volume = 345 | issue = 6204| pages = 1609–1613 | doi=10.1126/science.1256484| pmid = 25258079 | bibcode = 2014Sci...345.1609A | s2cid = 10266660 | url-access = subscription }}</ref> Aside from technique, the overarching commonality in Levallois complexes is the attention given to maximizing core efficiency. Lycett and von Cramon-Taubedel (2013) measured variability in shape and geometrics relationships between cores over multiple regions, with an outcome that suggests a tendency for knappers to choose planforms with a specific surface morphology. In other words, they conclude that Levallois knappers cared less about the overall outline or shape of their core and more about the striking surface, evidence of complex pre-planning and recognition of an "ideal form" of Levallois core.<ref name="Lycettvon Cramon-Taubadel2013"/> A recent article by Lycett and Eren (2013) statistically shows the efficiency of the Levallois technique which at times has been called into question. Lycett and Eren created 75 Levallois flakes from 25 Texas Chert nodules. They counted the 3957 flakes and separated them into four stages in order to show efficiency, which grew subsequently in each stage.<ref name="ReferenceA">{{cite journal|last1=Lycett|first1=S.J.|last2=M.I.|first2=Eren|title=Levallois economics: and examination of 'waste' production in experimental produced Levallois reduction sequences. |journal=Journal of Archaeological Science|date=2013|volume=40|issue=5|pages=2384–2392|doi=10.1016/j.jas.2013.01.016|bibcode=2013JArSc..40.2384L }}</ref> Based on the comparative study of 567 debitage flakes and 75 preferential Levallois flakes, Lycett and Eren found out the thickness is more evenly distributed and less variable across preferential Levallois flakes, which indicates the thickness is an important factor for efficiency and retouch potential.<ref>{{cite journal | last1 = Eren | first1 = M.I. | last2 = Lycett | first2 = S.J. | year = 2012 | title = Why Levallois? A Morphometric Comparison of Experimental 'Preferential' Levallois Flakes versus Debitage Flakes | doi = 10.1371/journal.pone.0029273 | journal = PLOS ONE | volume = 7 | issue = 1| page = 29273 | pmid=22291888 | pmc=3264556| bibcode = 2012PLoSO...729273E | doi-access = free }}</ref> The experiment<ref name="ReferenceA"/> also shows that the Levallois core is an economic optimal strategy of raw material (lithic) usage, which means it can generate longest cutting edge per weight unit of raw material. This result also implies that the mobility of prehistoric people was higher when applying Levallois technology; prehistoric people may explore more area with Levallois cores, which can make longer cutting edge than the other flake-making technique under same amount of cores, and no need to worry about the lack of raw material to make tools.

===Defining Levallois===
[[File:Pointe levallois Beuzeville MHNT PRE.2009.0.203.2.fond.jpg|thumb|Levallois point{{snds}}[[Beuzeville]]]]
There is disagreement when it comes to defining Levallois technology.<ref name="ReferenceB">{{cite journal|last1=Brantingham|first1=P. Jeffrey|last2=Kuhn|first2=Steven L.|title=Constraints on Levallois Core Technology: A Mathematical Model |journal=Journal of Archaeological Science|date=2001|volume=28|issue=7|page=749|doi=10.1006/jasc.2000.0594 |bibcode=2001JArSc..28..747B |s2cid=2080208}}</ref> Archeologists question which attributes and dimensions are specifically associated with Levallois, and argue that there are other techniques with similar cosmetic and functional aspects. Due to these disagreements, there is now a more precise set of criteria that outlines Levallois technology from a geometric standpoint. These criteria are:
# Exploitation of the volume of raw material is organized in terms of two intersecting planes, or flaking surfaces; 
# The two surfaces are hierarchically related, one constituting the striking platform and the other the primary reduction surface; 
# The primary reduction surface is shaped such that the morphology of the product is pre-determined, which is fundamentally a function of the lateral and distal convexities of the surface; 
# The fracture plane for removing primary products is sub-parallel to the plane of intersection of the two surfaces; and 
# The striking platform size and shape is adjusted to allow removal of flakes parallel to this plane, usually through retouch or faceting.<ref name="ReferenceB" />