Editing Coca (section)

== Species and evolution ==
There are two species of coca crops, each with two varieties:
*''[[Erythroxylum coca]]''
**''Erythroxylum coca'' var. ''coca'' (Bolivian or [[Huánuco]] Coca) – well adapted to the eastern [[Andes]] of [[Peru]] and [[Bolivia]], an area of humid, tropical, [[montane forest]].
**''Erythroxylum coca'' var. ''ipadu'' (Amazonian Coca) – cultivated in the lowland [[Amazon Basin]] in Peru and Colombia.
*''[[Erythroxylum novogranatense]]''
**''Erythroxylum novogranatense'' var. ''novogranatense'' (Colombian Coca) – a highland variety that is utilized in lowland areas. It is cultivated in drier regions found in Colombia. However, ''E. novogranatense'' is very adaptable to varying ecological conditions. The leaves have parallel lines on either side of the central vein. These plants are called "Hayo" or "Ayu" among certain groups in Venezuela and Colombia.
**''Erythroxylum novogranatense'' var. ''truxillense'' ([[Trujillo Province, Peru|Trujillo]] Coca) – grown primarily in the Cajamarca and Amazonas states in Peru, including for the [https://www.gob.pe/enaco Empresa Nacional de la Coca S.A]. and export by Coca-Cola for beverage flavoring.

All four of the cultivated cocas were domesticated from ''[[Erythroxylum gracilipes]]'' in pre-Columbian times,<ref name=":2" /> with significant archaeological sites reaching from Colombia to northern Chile, including the Las Vegas Culture in Ecuador, the [[Huaca Prieta]] site in Peru, and the Nanchoc valley in Peru – where leaf fragments and lime "cal" additives have been dated to over 8,000 years before present.<ref name="cambridge.org"/>

An initial theory of the origin and evolution of the cocas by [[Timothy Plowman|Plowman]]<ref name="Plowman1984">Plowman T. 1979. "Botanical Perspectives on Coca". ''Journal of Psychoactive Drugs,'' 11(1-2): 103-117. DOI: 10.1080/02791072.1979.10472095</ref> and Bohm<ref name="Bohm1982">{{cite journal |last=Bohm|first=B|author2=Ganders F|author3=Plowman T |title=Biosystematics and Evolution of Cultivated Coca (Erythroxylaceae) |journal=Systematic Botany|year=1982|volume=7 | issue = 2 |pages=121–133 |doi=10.2307/2418321 |jstor=2418321}}</ref> suggested that ''Erythroxylum coca'' var. ''coca'' is ancestral, while ''[[Erythroxylum novogranatense]]'' var. ''truxillense'' is derived from it to be drought tolerant, and ''Erythroxylum novogranatense'' var. ''novogranatense'' was further derived from ''Erythroxylum novogranatense'' var. ''truxillense'' in a linear series. In addition, E. coca var. ipadu was separately derived from ''E. coca'' var. ''coca'' when plants were taken into the Amazon basin.

Genetic evidence (Johnson et al. in 2005,<ref name="Johnson2005">{{cite journal |last=Johnson|first=E|author2=Zhang D|author3=Emche S |title=Inter- and Intra-specific Variation among Five Erythroxylum Taxa Assessed by AFLP |journal=Annals of Botany|year=2005|volume=95|issue=4|pages=601–608|doi=10.1093/aob/mci062|pmid=15650009|pmc=4246853}}</ref> Emche et al. in 2011,<ref name="Emche2011">{{cite journal |last=Emche|first=S|author2=Zhang D|author3=Islam M|author4=Bailey B|author5=Meinhardt L |title=AFLP Phylogeny of 36 Erythroxylum Species Genetic Relationships Among Erythroxylum Species Inferred by AFLP Analysis |journal=Tropical Plant Biology |year=2011|volume=4|pages=126–133|doi=10.1007/s12042-011-9070-9|s2cid=19680835}}</ref> and Islam 2011<ref name="Islam2011">Islam M.  [http://gradworks.umi.com/34/68/3468387.html Tracing the Evolutionary History of Coca (Erythroxylum)] [PhD thesis]. Boulder: University of Colorado, Boulder; 2011</ref>) does not support this linear evolution. None of the four coca varieties are found in the wild, despite prior speculation by Plowman that wild populations of E. coca var. coca occur in the Huánuco and San Martín provinces of Peru. Recent phylogenetic evidence shows the closest wild relatives of the coca crops are ''Erythroxylum gracilipes'' Peyr. and ''Erythroxylum cataractarum'' Spruce ex. Peyr,<ref>{{Cite journal |last1=White |first1=Dawson M. |last2=Islam |first2=Melissa B. |last3=Mason-Gamer |first3=Roberta J. |date=January 2019 |title=Phylogenetic inference in section Archerythroxylum informs taxonomy, biogeography, and the domestication of coca ( Erythroxylum species) |journal=American Journal of Botany |language=en |volume=106 |issue=1 |pages=154–165 |doi=10.1002/ajb2.1224 |pmid=30629286 |s2cid=58624026 |issn=0002-9122|doi-access=free }}</ref> and dense sampling of these species along with the coca crops from throughout their geographic ranges supports independent origins of domestication of ''Erythroxylum novogranatense'' and ''Erythroxylum coca'' from ancestor ''Erythroxylum gracilipes''.<ref name=":2" /> It is possible that Amazonian coca was produced by yet a third independent domestication event from ''Erythroxylum gracilipes''.<ref name=":2" />

Thus, different early-Holocene peoples in different areas of South America independently transformed ''Erythroxylum gracilipes'' plants into quotidian stimulant and medicinal crops now collectively called coca.<ref name=":2" />

=== Herbicide resistant varieties ===
Also known as ''supercoca'' or ''la millionaria'', [[Boliviana negra]] is a relatively new form of coca that is resistant to a [[herbicide]] called [[glyphosate]]. Glyphosate is a key ingredient in the multibillion-dollar aerial [[coca eradication]] campaign undertaken by the government of Colombia with U.S. financial and military backing known as [[Plan Colombia]].

The herbicide resistance of this strain has at least two possible explanations: that a "[[peer-to-peer]]" network of coca farmers used [[plant breeding|selective breeding]] to enhance this trait through tireless effort, or the plant was [[genetic engineering|genetically modified]] in a laboratory. In 1996, a [[biological patent|patented]] glyphosate-resistant [[soybean]] was marketed by [[Monsanto Company]], suggesting that it would be possible to genetically modify coca in an analogous manner. Spraying ''Boliviana negra'' with glyphosate would serve to strengthen its growth by eliminating the non-resistant [[weed]]s surrounding it. Joshua Davis, in the ''Wired'' article cited below, found no evidence of CP4 EPSPS, a protein produced by the glyphosate-resistant soybean, suggesting ''Bolivana negra'' was either created in a lab by a different technique or bred in the field.<ref>{{cite book|url=https://books.google.com/books?id=DExN86ryRuwC
|title=Evolutionary History: Uniting History and Biology to Understand Life on Earth, Edmund Russell |publisher=Cambridge University Press |access-date=2011-03-12|isbn=978-0-521-74509-3|year=2011}}</ref><ref>{{Citation
| last  = Davis
| first = Joshua
| title = The Mystery of the Coca Plant That Wouldn't Die
| magazine = WIRED
| volume  = 12
| issue   = 11
| year    = 2004
| url     = https://www.wired.com/wired/archive/12.11/columbia.html
}}</ref>