{{Short description|Conceptual lifeforms to assist in understanding phylogenrtics}} [[File:Caminalcules.jpg|thumb|300px|Eight of the Caminalcules]] '''Caminalcules''' are a fictive group of [[animal]]-like life forms, which were created as a tool for better understanding [[phylogenetics]] in real organisms. They were created by Joseph H. Camin ([[University of Kansas]]) and consist of 29 living 'species' and 48 fossil forms.<ref name=":0">{{cite journal|last=Sokal|first=R. R.|date=June 1983|title=A phylogenetic analysis of the Caminalcules. I. The data base|journal=Systematic Zoology|volume=32|issue=2|pages=159–184|doi=10.2307/2413279|jstor=2413279}}</ref>
The name of the taxon Caminalcules seems to come from Camin's last name and [[Antonie van Leeuwenhoek]]'s [[animalcule]]s.
== History == Joseph H. Camin (1922–1979) drew the Caminalcules in the early 1960s or possibly even earlier to study the nature of [[Taxonomy (biology)|taxonomic]] judgement.<ref name=":7" /> He assured that there was genetic continuity in the Caminalcules by the preservation of all characters except for changes that he desired in all successive animals. He did not keep track of the changes he made in the different species. The images of the Caminalcules were made using master [[stencil]]s. The images of the living [[Operational taxonomic unit|OTUs]] (29 species) were made available in the early 1960s; those of the fossil ones (48 species) later in the decade. These images were copied using [[xerography]]. Copies of all OTUs were in the possession of Dr. Paul A. Ehrlich ([[Stanford University]]), Dr. W. Wayne Moss (Philadelphia Academy of Sciences) and [[Robert R. Sokal]] ([[Stony Brook University|State University of New York at Stony Brook]]) in 1983.<ref name=":0" /> The original drawings by Joseph H. Camin have unfortunately been lost.<ref name=":0" />
The Caminalcules first appeared in print in the journal ''Systematic Zoology'' (now ''[[Systematic Biology]]'') in 1983, four years after Camin's death in 1979. [[Robert R. Sokal]] published four succeeding papers about them, titled "A Phylogenetic Analysis of the Caminalcules."<ref name=":0" /><ref name=":1">{{cite journal|last=Sokal|first=R. R.|date=June 1983|title=A phylogenetic analysis of the Caminalcules. II. Estimating the true cladogram|journal=Systematic Zoology|volume=32|issue=2|pages=185–201|doi=10.2307/2413280|jstor=2413280}}</ref><ref name=":2">{{cite journal|last=Sokal|first=R. R.|date=September 1983|title=A phylogenetic analysis of the Caminalcules. III. Fossils and Classification|journal=Systematic Zoology|volume=32|issue=3|pages=248–258|doi=10.2307/2413445|jstor=2413445}}</ref><ref>{{cite journal|last=Sokal|first=R. R.|date=September 1983|title=A phylogenetic analysis of the Caminalcules. IV. Congruence and Character Stability|journal=Systematic Zoology|volume=32|issue=3|pages=259–275|doi=10.2307/2413446|jstor=2413446}}</ref> These papers included the complete set of living and fossil species, as well as their cladogram, which Sokal had received from Camin in 1970.<ref name=":1" />
At a symposium dedicated to Camin, Dr. W. Wayne Moss said that "his collaborative studies on methods and principles of systematics at Kansas in the 1960s resulted in the appearance of that delightful taxon, the Caminalcules", and that "his thoughts helped to launch the infant field of phenetics and cladistics in North America".<ref name=":7">{{Cite journal|last=Moss|first=W. W.|date=1979|title=Dedication to Joseph H. Camin (1922-1979)|journal=American Zoologist|volume=19|issue=4|pages=1179|doi=10.1093/icb/19.4.1179|doi-access=free}}</ref> This quote demonstrates the importance of the Caminalcules for the field of phylogenetics.
Ulrich Wirth introduced also the fictive animal group Didaktozoa in 1993, which was inspired by [[rotifer]]s. According to Ulrich, the Didaktozoa are handier than the Caminalcules and were created in a way that more biologists would agree with, since phenomena such as [[Homology (biology)|homologous structures]], [[Synapomorphy and apomorphy|apomorphy]] and organ reduction were taken into account in their creation.<ref>{{Cite book|last=Wirth|first=U.|chapter=Caminalcules and Didaktozoa: Imaginary Organisms as Test-Examples for Systematics |date=1993|editor-last=Opitz|editor-first=Otto|editor2-last=Lausen|editor2-first=Berthold|editor3-last=Klar|editor3-first=Rüdiger|title=Information and Classification|chapter-url=https://link.springer.com/chapter/10.1007/978-3-642-50974-2_43|series=Studies in Classification, Data Analysis and Knowledge Organization|language=en|location=Berlin, Heidelberg|publisher=Springer|pages=421–433|doi=10.1007/978-3-642-50974-2_43|isbn=978-3-642-50974-2}}</ref>
== Use in assessment and development of taxonomic methods == The Caminalcules have a known [[phylogeny]], whereas for real organisms it is generally impossible to obtain one. Therefore, Camin expected that they would be useful in evaluating different taxonomic techniques, such as [[Phenetics|phenetic]] and [[Cladistics|cladistic]] analysis.<ref name=":3">{{Cite journal|last=Gendron|first=R. P.|date=2000|title=The classification and evolution of Caminalcules|journal=The American Biology Teacher|volume=62|issue=8|pages=570–576|doi=10.2307/4450980|jstor=4450980}}</ref> This was indeed the case; for example, Robert R. Sokal used the Caminalcules to investigate the ability of different numerical methods to estimate the true [[cladogram]]<ref name=":1" /> as well as the consequences of introducing fossil species into a data set for cladistic and phenetic classifications.<ref name=":2" /> Whereas nowadays cladograms are usually created by applying [[algorithm]]ic methods to [[DNA sequencing|gene sequences]], Sokal numerically compared the [[Morphology (biology)|morphological]] characteristics of organisms, rather than their genetic information.<ref>{{Cite web|last=Agapakis|first=C.|date=27 March 2013|title=Synthetic classification: The evolution of imaginary animals|url=https://blogs.scientificamerican.com/oscillator/synthetic-classification/|access-date=16 September 2020|website=Scientific American}}</ref><ref name=":1" />
The Caminalcules can be used as a tool for evaluating taxonomic methods by virtue of their similarity to data sets of real organisms. Many of their properties, including [[Rate of evolution|evolutionary rates]], species longevity, [[homoplasy]], [[Parallelism (biology)|parallelism]], and other measures for quantifying evolutionary change, are within the range of values that have been observed for real organisms.<ref name=":0" /> However, the [[taxonomic diversity]] distribution of the Caminalcules differs from the taxonomic diversity distributions of real animals and plants, since it does not follow a hollow curve.<ref>{{Cite journal|last=Holman|first=E. W.|date=1986|title=A Taxonomic Difference Between the Caminalcules and Real Organisms|url=https://www.jstor.org/stable/2413437|journal=Systematic Zoology|volume=35|issue=2|pages=259–261|doi=10.2307/2413437|jstor=2413437|issn=0039-7989|url-access=subscription}}</ref>
== Use in education == Caminalcules are commonly used in secondary school and undergraduate university curriculums as a tool for teaching principles of [[phylogeny]] and [[evolution]].<ref name=":4">{{Cite journal|last=Cruz|first=R. A. L.|date=2017|title=Here Be Dragons: Using Dragons as Models for Phylogenetic Analysis|url=https://online.ucpress.edu/abt/article-abstract/79/7/544/18946/Here-Be-Dragons-Using-Dragons-as-Models-for?redirectedFrom=fulltext|journal=The American Biology Teacher|language=en|volume=79|issue=7|pages=544–551|doi=10.1525/abt.2017.79.7.544|s2cid=91044116|issn=0002-7685|url-access=subscription}}</ref><ref name=":3" /><ref name=":5">{{Cite journal|last1=Russo|first1=C. A. M.|last2=Aguiar|first2=B. O.|last3=Voloch|first3=C. M.|last4=Selvatti|first4=A. P.|date=2016|title=When Chinese Masks Meet Phylogenetics|journal=The American Biology Teacher|volume=78|issue=3|pages=241–247|doi=10.1525/abt.2016.78.3.241|s2cid=87808288}}</ref> They can, for example, be used to illustrate the concepts of [[Maximum parsimony (phylogenetics)|parsimony]] and [[convergent evolution]].<ref name=":3" /><ref name=":4" />
Students are typically asked to construct a phylogenetic tree based on the morphological characteristics of the Caminalcules and taking into account evolutionary principles. In an article in [[National Association of Biology Teachers|''American Biology Teacher'']], Robert P. Gendron published instructions for a lesson plan in which students are first asked to construct a potential tree based solely on the living Caminalcules, followed by a definitive tree that includes the fossil species.<ref name=":3" /> Many secondary and tertiary educational institutions around the world have adopted lesson plans that follow this sequence. Some examples are the [[New York City Lab School for Collaborative Studies]],<ref>Drozd, A. (April 5, 2019). Caminalcules instructions by Susan Price [Video file]. https://www.youtube.com/watch?v=D-a-SSX8pns&ab_channel=AndrewDrozd </ref> the [[University of Miami]],<ref>Caminalcules. (n.d.). University of Miami. http://www.bio.miami.edu/dana/107/Caminalcules.pdf</ref> [[Carleton College]],<ref>{{Cite web|last=Ausich|first=W. I.|title=Caminalcule phylogenetic exercise|url=http://sec.carleton.edu/NAGTWorkshops/paleo/activities/33186.html|access-date=16 September 2020|website=SERC}}{{Dead link|date=September 2025 |bot=InternetArchiveBot }}</ref> and the Turkana Basin Institute.<ref>{{Cite web|last=Yang|first=D.|date=22 March 2017|title=A family tree of Caminalcules|url=http://turkanabasin.org/2017/03/a-family-tree-of-caminalcules/|access-date=16 September 2020|website=Turkana Basin Institute}}</ref> Notably, the United States’ [[National Park Service]] also uses the Caminalcules in their lesson plans about evolution.<ref>{{Cite web|title=Canon Paleo Curriculum Unit 3: Evolution Lesson Plan 5|url=http://nps.gov/flfo/learn/education/upload/Unit3Lesson5/pdf|access-date=16 September 2020|archive-url=https://web.archive.org/web/20170224065343/https://www.nps.gov/flfo/learn/education/upload/Unit3Lesson5.pdf|url-status=dead|archive-date=February 24, 2017|website=National Park Service}}</ref><ref>{{Cite web|title=Canon Paleo Curriculum Unit 3: Evolution Lesson Plan 6|url=http://nps.gov/flfo/learn/education/upload/Unit3Lesson6.pdf|archive-url=https://web.archive.org/web/20150226033608/http://www.nps.gov/flfo/learn/education/upload/Unit3Lesson6.pdf|url-status=dead|archive-date=February 26, 2015|access-date=16 September 2020|website=National Park Service}}</ref>
Using Caminalcules to practice the construction of phylogenetic trees has an advantage over using data sets consisting of real organisms, because it prevents the students’ pre-existing knowledge about the classification of real organisms to influence their reasoning during the exercise.<ref name=":3" /> They may only use the given data set and the principles of evolution to come to a solution, which is how real taxonomic problems are solved as well.
There are many other popular phylogenetic exercises that use different sets of ‘organisms’, some of which were inspired by the Caminalcule exercises.<ref name=":6">{{Cite journal|last=Brown|first=C. G.|date=2016|title=Modeling Macroevolution with Invented Creatures|url=https://online.ucpress.edu/abt/article-abstract/78/2/141/19002|journal=The American Biology Teacher|language=en|volume=78|issue=2|pages=141–148|doi=10.1525/abt.2016.78.2.141|s2cid=86141486|issn=0002-7685|url-access=subscription}}</ref><ref name=":4" /> Potential alternative data sets include sets of twigs,<ref>{{Cite journal|last=Flinn|first=K. M.|date=2015|title=Building a Twig Phylogeny|url=https://www.jstor.org/stable/10.1525/abt.2015.77.2.10|journal=The American Biology Teacher|volume=77|issue=2|pages=141–144|doi=10.1525/abt.2015.77.2.10|jstor=10.1525/abt.2015.77.2.10|s2cid=83841790|issn=0002-7685|url-access=subscription}}</ref> chocolate bars,<ref>{{Cite journal|last1=Burks|first1=R. L.|last2=Boles|first2=L. C.|date=2007|title=Evolution of the Chocolate Bar: A Creative Approach to Teaching Phylogenetic Relationships within Evolutionary Biology|url=https://online.ucpress.edu/abt/article-abstract/69/4/229/17711/Evolution-of-the-Chocolate-Bar-A-Creative-Approach?redirectedFrom=fulltext|journal=The American Biology Teacher|language=en|volume=69|issue=4|pages=229–237|doi=10.2307/4452143|jstor=4452143|issn=0002-7685|url-access=subscription}}</ref> Chinese masks,<ref name=":5" /> and dragons.<ref name=":4" /> Students may also be asked to create their own sets of fictional organisms, which has the additional value of demonstrating macroevolutionary processes.<ref name=":6" /> Furthermore, in the case of data sets without a known phylogeny, unlike the case of the Caminalcules, students may find multiple, equally correct solutions. This may demonstrate the fact that taxonomic questions do not always have a single correct response, since the true phylogeny often remains unknown.<ref name=":5" />
==References== {{Reflist}}
==Further reading== *{{cite journal |last=Sokal |first=R. R.|author2=K. L. Fiala |author3=G. Hart |date=December 1984 |title=OTU Stability and Factors Determining Taxonomic Stability: Examples from the Caminalcules and the Leptopodomorpha |journal=Systematic Zoology |volume=33 |issue=4 |pages=387–407 |doi=10.2307/2413091|jstor=2413091 }} *{{cite journal |last=Holman |first=E. W. |date=June 1986 |title=A Taxonomic Difference Between the Caminalcules and Real Organisms |journal=Systematic Zoology |volume=35 |issue=2 |pages=259–261 |doi=10.2307/2413437|jstor=2413437 }} *{{cite journal |last=Gendron |first=R. P. |date=October 2000 |title=The Classification & Evolution of Caminalcules |journal=The American Biology Teacher |volume=62 |issue=8 |pages=570–576 |doi=10.1662/0002-7685(2000)062[0570:TCEOC]2.0.CO;2|jstor=4450980 |s2cid=86463122 }}
==External links== <!-- More needed --> *[https://web.archive.org/web/20120802103944/http://nsm1.nsm.iup.edu/rgendron/Caminalcules.shtml The Evolution of Caminalcules] - "Caminalcules, Snouters and Other Unusual Creatures" *[https://web.archive.org/web/20100531200649/http://www.hartnell.edu/faculty/kharris/bio10labmanual/ Biology 10 Lab Manual] Caminalcules activity on Taxonomy and phylogeny, Harris, K (2010) *[https://web.archive.org/web/20220709152204/https://sites.google.com/a/xtec.cat/caminalcules/ Chasing after Caminalcules] Inquiry-Based Science Education activity based on Caminalcules, Domènech, J. (2013)
[[Category:Phylogenetics]] [[Category:Fictional animals]]