Editing Swarm behaviour (section)

===Plants===
Scientists have attributed swarm behavior to plants for hundreds of years. In his 1800 book, ''Phytologia: or, The philosophy of agriculture and gardening'', [[Erasmus Darwin]] wrote that plant growth resembled swarms observed elsewhere in nature.<ref>{{cite book |url=https://books.google.com/books?id=YggpAAAAYAAJ|title=Phytologia: Or, The Philosophy of Agriculture and Gardening. With the Theory of Draining Morasses and with an Improved Construction of the Drill Plough|last=Darwin|first=Erasmus|date=1800-01-01|publisher=P. Byrne|language=en}}</ref> While he was referring to more broad observations of plant morphology, and was focused on both root and shoot behavior, recent research has supported this claim.

[[Plant root]]s, in particular, display observable swarm behavior, growing in patterns that exceed the statistical threshold for random probability, and indicate the presence of communication between individual [[Root apex (botany)|root apexes]]. The primary function of plant roots is the uptake of [[soil nutrient]]s, and it is this purpose which drives swarm behavior. Plants growing in close proximity have adapted their growth to assure optimal nutrient availability. This is accomplished by growing in a direction that optimizes the distance between nearby roots, thereby increasing their chance of exploiting untapped nutrient reserves. The action of this behavior takes two forms: maximization of distance from, and repulsion by, neighboring root apexes.<ref>{{cite journal |last1=Ciszak|first1=Marzena|last2=Comparini|first2=Diego|last3=Mazzolai|first3=Barbara|last4=Baluska|first4=Frantisek|last5=Arecchi|first5=F. Tito|last6=Vicsek|first6=Tamás|last7=Mancuso|first7=Stefano|date=2012-01-17|title=Swarming Behavior in Plant Roots|journal=PLOS ONE|volume=7|issue=1|doi=10.1371/journal.pone.0029759|issn=1932-6203|pmc=3260168|pmid=22272246|page=e29759|bibcode=2012PLoSO...729759C|doi-access=free}}</ref> The transition zone of a root tip is largely responsible for monitoring for the presence of soil-borne hormones, signaling responsive growth patterns as appropriate. Plant responses are often complex, integrating multiple inputs to inform an autonomous response. Additional inputs that inform swarm growth includes light and gravity, both of which are also monitored in the transition zone of a root's apex.<ref>{{cite journal |last1=Baluška|first1=František|last2=Mancuso|first2=Stefano|last3=Volkmann|first3=Dieter|last4=Barlow|first4=Peter W.|date=2010-07-01|title=Root apex transition zone: a signalling–response nexus in the root|journal=Trends in Plant Science|volume=15|issue=7|pages=402–408|doi=10.1016/j.tplants.2010.04.007|pmid=20621671|bibcode=2010TPS....15..402B }}</ref> These forces act to inform any number of growing "main" roots, which exhibit their own independent releases of inhibitory chemicals to establish appropriate spacing, thereby contributing to a swarm behavior pattern. Horizontal growth of roots, whether in response to high mineral content in soil or due to [[stolon]] growth, produces branched growth that establish to also form their own, independent root swarms.<ref>{{cite book |title=Plant behaviour and intelligence|last=J.|first=Trewavas, A.|date=2014|publisher=Oxford university press|isbn=9780199539543|oclc=961862730}}</ref>