Editing Anolis

{{Short description|Genus of lizards}}
{{Automatic taxobox
| fossil_range = {{fossilrange|Early Miocene|present}}
| image = Anole.jpg
| image_caption = Green anole (''[[Anolis carolinensis]]'')
| taxon = Anolis
| authority = [[François Marie Daudin|Daudin]], 1802
| type_species = ''[[Anolis punctatus]]''
| type_species_authority = [[François Marie Daudin|Daudin]], 1802
| subdivision_ranks = Species
| subdivision = ''circa'' 425 spp., see [[#Species|text]]
}}

'''''Anolis''''' is a [[genus]] of [[anole]]s ({{IPAc-en|US|audio=en-us-anole.ogg|ə|ˈ|n|oʊ|.|l|i|z|}}), [[iguania]]n lizards in the family [[Dactyloidae]], native to the [[Americas]]. With more than 425 species,<ref name=ReptileDatabaseFamily>{{cite web |author1=Uetz, P. |author2=Hallermann, J. | year=2018 |url=http://reptile-database.reptarium.cz/advanced_search?taxon=Dactyloidae&exact%5B0%5D=taxon&submit=Search | title=Dactyloidae |publisher=[[The Reptile Database]] |access-date=5 November 2018}}</ref> it represents the world's most species-rich [[amniote]] [[tetrapod]] genus, although many of these have been proposed to be moved to other genera, in which case only about 45 ''Anolis'' species remain.<ref name=Nicholson2012>{{Cite journal|author1=Nicholson, Kirsten E. |author2=Crother, Brian I. |author3=Guyer, Craig |author4=Savage, Jay M. |year=2012|title=It is time for a new classification of anoles (Squamata: Dactyloidae) |journal=Zootaxa |volume=3477 |number=1|pages=1–108, page 38 |url=http://www.southeastern.edu/acad_research/depts/biol/faculty/pdf/nicholson_et_al2012.pdf |archive-url=https://web.archive.org/web/20160130193500/http://www.southeastern.edu/acad_research/depts/biol/faculty/pdf/nicholson_et_al2012.pdf |archive-date=30 January 2016|url-status=live|doi=10.11646/zootaxa.3477.1.1 |doi-access=free |ref={{sfnref|Nicholson|2012}}}} [http://www.mapress.com/zootaxa/2012/f/z03477p108f.pdf Abstract]</ref><ref name=Nicholson2018>{{cite journal| author1=Nicholson, K.A. | author2=B.I. Crother | author3=C. Guyer | author4=J.M. Savage | year=2018 | title=Translating a clade based classification into one that is valid under the international code of zoological nomenclature: the case of the lizards of the family Dactyloidae (Order Squamata) | journal=Zootaxa | volume=4461 | issue=4 | pages=573–586 | doi=10.11646/zootaxa.4461.4.7 | pmid=30314068 | s2cid=52975031 }}</ref> Previously, it was classified under the family Polychrotidae that contained all the anoles, as well as ''[[Polychrus]]'', but recent studies place it in the Dactyloidae.<ref name=Nicholson2012/>

== Taxonomy ==
{{See also|Dactyloidae#Genera}}

This very large [[genus]] displays considerable [[paraphyly]], but [[phylogenetic analysis]] suggests a number of subgroups or [[clades]].<ref name=Nicholson2012/><ref name=Glor>{{cite journal | last1 = Glor | first1 = Richard E. | last2 = Jonathan | first2 = B. Losos | last3 = Larson | first3 = Allan | year = 2005 | title = Out of Cuba: overwater dispersal and speciation among lizards in the ''Anolis carolinensis'' subgroup | url = http://lacertilia.com/research/PDF/Glor_etal_2005.pdf | journal = Molecular Ecology | volume = 14 | issue = 8| pages = 2419–2432 | doi = 10.1111/j.1365-294X.2005.02550.x | pmid=15969724| bibcode = 2005MolEc..14.2419G | s2cid = 20092906 }}</ref> Whether these clades are best recognized as subgenera within ''Anolis'' or separate genera remains a matter of dispute.<ref name=Nicholson2012/><ref name=Nicholson2018/><ref name=Poe2017>{{cite journal| author1=Poe | author2=Nieto-Montes de Oca | author3=Torres-Carvajal | author4=Queiroz | author5=Velasco | author6=Truett | author7=Gray | author8=Ryan | author9=Köhler | author10=Ayala-Varela | author11=Latella | year=2017 | title=A Phylogenetic, Biogeographic, and Taxonomic study of all Extant Species of Anolis (Squamata; Iguanidae) | journal=Systematic Biology | volume=66 | issue=5 | pages=663–697 | doi=10.1093/sysbio/syx029 | pmid=28334227 | doi-access=free }}</ref>

If the clades are recognized as full genera, about 45 species remain in ''Anolis'', with the remaining moved to ''Audantia'' (9 species), ''Chamaelinorops'' (7 species), ''Ctenonotus'' (more than 40 species), ''Dactyloa'' (''circa'' 95 species), ''Deiroptyx'' (almost 35 species), ''Norops'' (about 190 species), and ''Xiphosurus'' (around 15 species).<ref name=Nicholson2012/><ref name=Nicholson2018/> Some of these can be further subdivided. For example, ''Phenacosaurus'' was often listed as a full genus in the past, but it is a subclade within ''Dactyloa'' (''Dactyloa heteroderma'' species group).<ref>{{harvnb|Nicholson|2012|page=17}}</ref> Among the subgroups within ''Anolis'' are:

* ''[[carolinensis]]'' species group (13 [[species]])
* ''isolepis'' species group (three species)

In 2011, the [[Green anole|green (or Carolina) anole]] (''Anolis carolinensis'') became the first reptile to have its complete genome published.<ref>{{cite journal |url= https://www.nature.com/news/2011/110831/full/news.2011.512.html |journal= Nature|last1=Sweetlove |first1=Lee |title= Lizard genome unveiled |date= 2011-08-31|doi= 10.1038/news.2011.512 }}</ref>

Closely related, recently diverged anole lizards exhibited more divergence in thermal biology than in morphology. These anole lizards are thought to have the same structural niche and have similarities in their size and shape, but they inhabit different climatic niches with was variability in temperature and openness of the environment. This suggests that thermal physiology is more associated with recently diverged anole lizards.<ref>Losos, J. B. (2009). Lizards in an evolutionary tree: ecology and adaptive radiation of anoles. University of California Press, Berkeley, CA.</ref><ref>{{cite journal | last1 = Hertz | first1 = P.E. | last2 = Arima | first2 = Y. | last3 = Harrison | first3 = A. | last4 = Huey | first4 = R.B. | last5 = Losos | first5 = J.B. | last6 = Glor | first6 = R.E. | year = 2012 | title = Asynchronous evolution of physiology and morphology in Anolis lizards | journal = Org. Evol. | volume = 67 | issue = 7| pages = 2101–2113 | doi=10.1111/evo.12072| pmid = 23815663 | s2cid = 2793493 | doi-access = free }}</ref>

==Ecomorphs==
{{Main|Anolis ecomorph}}
''Anolis'' lizards are some of the best examples of both [[adaptive radiation]] and [[convergent evolution]]. Populations of lizards on isolated islands diverge to occupy separate [[ecological niches]], mostly in terms of the location within the vegetation where they forage (such as in the crown of trees vs. the trunk vs. underlying shrubs).<ref name="Losos">{{cite journal | last1 = Losos | first1 = J.B. | year = 2007 | title = Detective work in the West Indies: integrating historical and experimental approaches to study island lizard evolution | url = https://dash.harvard.edu/bitstream/handle/1/2643861/Losos_DetectiveWorkinWestIndies.pdf?sequence=2| journal = BioScience | volume = 57 | issue = 7| pages = 585–597 | doi=10.1641/b570712| s2cid = 6869606 | doi-access = free }}</ref> These divergences in [[habitat]] are accompanied by [[Morphology (biology)|morphological]] changes primarily related to moving on the substrate diameter they most frequently encounter, with twig ecomorphs having short limbs, while trunk ecomorphs have long limbs.

In addition, these patterns repeat on numerous islands, with animals in similar habitats converging on similar body forms repeatedly.<ref name="Losos" /><ref>{{cite journal | last1 = Losos | first1 = J. B. | last2 = Jackman | first2 = T. R. | last3 = Larson | first3 = A. | last4 = de Queiroz | first4 = K. | last5 = Rodriguez-Schettino | first5 = L. | year = 1998 | title = Contingency and determinism in replicated adaptive radiations of island lizards | journal = Science | volume = 279 | issue = 5359| pages = 2115–2118 | doi=10.1126/science.279.5359.2115| pmid = 9516114 | bibcode = 1998Sci...279.2115L }}</ref> This demonstrates adaptive radiation can actually be predictable based on habitat encountered, and experimental introductions onto formerly lizard-free islands have proven ''Anolis'' evolution can be predicted.<ref>{{cite journal | last1 = Calsbeek | first1 = R | year = 2008 | title = Experimental evidence that competition and habitat use shape the individual fitness surface | journal = Journal of Evolutionary Biology | volume = 22 | issue = 1| pages = 97–108 | doi=10.1111/j.1420-9101.2008.01625.x | pmid=19120813| s2cid = 25745447 }}</ref><ref>{{cite journal | last1 = Calsbeek | first1 = R. | last2 = Buermann | first2 = W. | last3 = Smith | first3 = T.B. | year = 2009 | title = Parallel shifts in ecology and natural selection in an island lizard | journal = BMC Evolutionary Biology | volume = 9 | issue = 1 | page = 3 | doi=10.1186/1471-2148-9-3 | pmid=19126226 | pmc=2630972 | doi-access = free | bibcode = 2009BMCEE...9....3C }}</ref><ref>{{cite journal | last1 = Calsbeek | first1 = R. | last2 = Cox | first2 = R.M. | year = 2010 | title = Experimentally assessing the relative importance of predation and competition as agents of selection | journal = Nature | volume = 465 | issue = 7298| pages = 613–616 | doi=10.1038/nature09020 | pmid=20453837| bibcode = 2010Natur.465..613C | s2cid = 4326027 }}</ref><ref>{{cite journal | last1 = Calsbeek | first1 = R. | last2 = Smith | first2 = T.B. | year = 2007 | title = Probing the adaptive landscape using experimental islands: density-dependent natural selection on lizard body size | journal = Evolution | volume = 61 | issue = 5| pages = 1052–1061 | doi=10.1111/j.1558-5646.2007.00093.x | pmid=17492960| s2cid = 4643163 | doi-access = free }}</ref>

After appearing on each of the four [[Greater Antilles|Greater Antillean Islands]] about 50 million years ago, ''Anolis'' lizards spread on each island to occupy niches in the island's trees. Some living in the tree canopy area, others low on the tree trunk near the ground; others in the mid-trunk area, others on twigs. Each new species developed its own distinct body type, called an [[Ecomorphology|ecomorph]], adapted to the tree niche where it lived. Together, the different species occupied their various niches in the trees as a "[[community]]". A study of lizard fossils trapped in amber shows that the lizard communities have existed for about 20 million years or more. Four modern ecomorph body types, trunk-crown, trunk-ground, trunk, and twig, are represented in the amber fossils study. Close comparison of the lizard fossils with their descendants alive today in the Caribbean shows the lizards have changed little in the millions of years.<ref>{{Cite web|title = Trapped in Amber: Ancient fossils reveal remarkable stability of Caribbean lizard communities|date = 27 July 2015|url = http://smithsonianscience.si.edu/2015/07/trapped-in-amber-ancient-fossils-reveal-remarkable-stability-of-caribbean-lizard-communities/|access-date = 2015-07-28}}</ref><ref>{{Cite journal|title = Amber fossils demonstrate deep-time stability of Caribbean lizard communities|journal = Proceedings of the National Academy of Sciences|date = 2015-07-27|issn = 0027-8424|pmid = 26216976|pages = 9961–9966|doi = 10.1073/pnas.1506516112|first1 = Emma|last1 = Sherratt|first2 = María del Rosario|last2 = Castañeda|first3 = Russell J.|last3 = Garwood|first4 = D. Luke|last4 = Mahler|first5 = Thomas J.|last5 = Sanger|first6 = Anthony|last6 = Herrel|first7 = Kevin de|last7 = Queiroz|first8 = Jonathan B.|last8 = Losos|volume=112|issue = 32|pmc=4538666|bibcode = 2015PNAS..112.9961S|doi-access = free}}</ref>

== Behavior ==
As ectotherms, ''Anolis'' lizards must regulate their body temperature partly through behavioral changes and bask in the sunlight to gain enough heat to become fully active, but lizards cannot behaviorally warm themselves at night when temperatures drop. Because of this, cold tolerance evolves faster than heat tolerance in these lizards.<ref>{{Cite journal|last1=Muñoz|first1=Martha M.|author1-link=Martha M. Muñoz|last2=Stimola|first2=Maureen A.|last3=Algar|first3=Adam C.|last4=Conover|first4=Asa|last5=Rodriguez|first5=Anthony J.|last6=Landestoy|first6=Miguel A.|last7=Bakken|first7=George S.|last8=Losos|first8=Jonathan B.|date=2014-03-07|title=Evolutionary stasis and lability in thermal physiology in a group of tropical lizards|url=http://dx.doi.org/10.1098/rspb.2013.2433|journal=Proceedings of the Royal Society B: Biological Sciences|volume=281|issue=1778|pages=20132433|doi=10.1098/rspb.2013.2433|pmid=24430845|pmc=3906933|issn=0962-8452}}</ref> On the island of [[Hispaniola]], both high-altitude and low-altitude lizard populations exist, and the thermal conditions at high and low elevations differ significantly.<ref>{{Cite journal|last1=Muñoz|first1=Martha M.|author1-link=Martha M. Muñoz|last2=Losos|first2=Jonathan B.|date=January 2018|title=Thermoregulatory Behavior Simultaneously Promotes and Forestalls Evolution in a Tropical Lizard|url=https://www.journals.uchicago.edu/doi/pdf/10.1086/694779|journal=The American Naturalist|volume=191|issue=1|pages=E15–E26|doi=10.1086/694779|pmid=29244559|s2cid=3918571|issn=0003-0147}}</ref> High-altitude lizards have shifted their ecological niche to boulder environments, where warming themselves is easier, and they show changes in the shape of limbs and skull that make them better adapted to these environments.

To escape dangers, species that evolved near water have adapted the ability to stay submerged for as long as 18 minutes.<ref>[https://eeb.utoronto.ca/2021/05/evolutionary-biologists-discover-mechanism-that-enables-lizards-to-breathe-underwater/ Evolutionary biologists discover mechanism that enables lizards to breathe underwater]</ref>

==Species==
{{Main|List of Anolis lizards}}
The ''Anolis'' lizards that are less susceptible to predation are those with a dewlap in which both the scales and the exposed skin areas between them match the usual pale gray or whitish of the rest of the ventral surface.<ref>{{cite journal | last1 = Fitch | first1 = H.S. | last2 = Hillis | first2 = D.M. | year = 1984 | title = The anolis dewlap: Interspecific variability and morphological associations with habitat | journal = Copeia | volume = 1984 | issue = 2| pages = 315–323 | doi=10.2307/1445187| jstor = 1445187 }}</ref>

==Dewlap==
The dewlap is a flap of skin found beneath the jaw or throat of ''Anolis'' lizards. It can present in a variety of colorations, and is most present in male anoles. The dewlap is extended by means of the hyoid muscles in the throat, and can be flashed in a "pulse" pattern where the flap is extended repeatedly, or a "moving flag" pattern, where the lizard flashes it continuously while bobbing up and down.<ref name="Persons Fleishman Frye Stimphil 1999 pp. 585–607">{{cite journal | last1=Persons | first1=M. H. | last2=Fleishman | first2=L. J. | last3=Frye | first3=M. A. | last4=Stimphil | first4=M. E. | title=Sensory response patterns and the evolution of visual signal design in anoline lizards | journal=Journal of Comparative Physiology A: Sensory, Neural, and Behavioral Physiology | publisher=Springer Science and Business Media LLC | volume=184 | issue=6 | date=1999-07-05 | issn=0340-7594 | doi=10.1007/s003590050358 | pages=585–607| s2cid=21160410 }}</ref> The coloration of the dewlap is caused by two pigments, [[pterin]]s and [[carotenoid]]s. Pterin pigments are compounds synthesized from [[guanine]], whereas carotenoids are pigments acquired from the diet.<ref>{{cite journal | last1=Steffen | first1=John E. | last2=McGraw | first2=Kevin J. | title=Contributions of pterin and carotenoid pigments to dewlap coloration in two anole species | journal=Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology | publisher=Elsevier BV | volume=146 | issue=1 | year=2007 | issn=1096-4959 | doi=10.1016/j.cbpb.2006.08.017 | pages=42–46| pmid=17056290 }}</ref> Both cause the red-yellow hues most commonly found in ''Anolis'' lizard dewlaps. The function of the dewlap in ''Anolis'' lizards has been a topic of debate for centuries. It is thought that the dewlap is flashed as a visual signal for other competing males, or as a courtship signal for single females. It has also been hypothesized that the dewlap serves as a signal for sex recognition.<ref name="Sigmund 1983 p. 137">{{cite journal | last=Sigmund | first=William R. | title=Female Preference for Anolis carolinensis Males as a Function of Dewlap Color and Background Coloration | journal=Journal of Herpetology | publisher=JSTOR | volume=17 | issue=2 | year=1983 | pages=137–143 | issn=0022-1511 | doi=10.2307/1563454 | jstor=1563454 }}</ref>

[[File:Anolis carolinensis 207880066.jpg|thumb|Pink dewlap on an Anolis carolinensis lizard]]

===Initial studies===
The first study done on dewlap function was by Mertens (1926). The initial assumption was that the dewlap was flashed as a method of [[sexual selection]], and that the males would use it in order to attract females. It is hypothesized that female ''Anolis'' lizards are more attracted to males who flash their dewlaps more often, or have more brightly colored dewlaps.<ref name="Sigmund 1983 p. 137" /> This was then challenged by the hypothesis that males flashed their dewlap as a way to threaten other males in the area.<ref>{{cite journal | last1=NOBLE | first1=G. K. | last2=BRADLEY | first2=H. T. | title=The Mating Behavior of Lizards; ITS Bearing on the Theory of Sexual Selection | journal=Annals of the New York Academy of Sciences | publisher=Wiley | volume=35 | issue=1 | year=1933 | issn=0077-8923 | doi=10.1111/j.1749-6632.1933.tb55365.x | pages=25–100| bibcode=1933NYASA..35...25N | s2cid=85270929 }}</ref> During intermale fights, dewlaps are flashed. More currently, many studies have been done on the dewlap as a function for [[Intra-species recognition|species recognition]], with focus on the relationship of the contrast between dewlap color and environment.

===Relationship with environment===
The dewlap comes in a variety of colors, including yellow, blue, and red. It was previously believed that the color of the dewlap is what mattered most in interlizard interactions, but it has since been found that there exists a relationship between habitat light conditions and dewlap color.<ref>{{cite journal | last1=Fleishman | first1=Leo J. | last2=Perez-Martinez | first2=Christian A. | last3=Leal | first3=Manuel | title=Can Sensory Drive Explain the Evolution of Visual Signal Diversity in Terrestrial Species? A Test with ''Anolis'' Lizards | journal=The American Naturalist | publisher=University of Chicago Press | volume=200 | issue=2 | date=2022-08-01 | issn=0003-0147 | doi=10.1086/720267 | pages=236–249| pmid=35905402 | s2cid=247884850 | doi-access=free }}</ref><ref name="Persons Fleishman Frye Stimphil 1999 pp. 585–607" /> This means that, rather than the color being of importance, it is the contrast of the dewlap against the background of its environment that best visually signals to other lizards. There have been many methods used to determine this. Persons et. al (1999) found that the probability of a dewlap showing being detected goes up with the contrast of dewlap against the background. They determined this by measuring the number of times a "positive response" of the lizard's eyes turning towards a flashed dewlap occurred among different background contrasts. Similarly, Leal and Fleishman (2002) found that the light conditions in which a lizard displays its dewlap affects the probability of it being visually detected. They did this by measuring the UV spectral reflectance of dewlaps in ''Anolis cristatellus'' lizards using a [[spectroradiometer]], then measuring the spectral sensitivity of the lizards’ retinal responses using electroretinographic (ERG) flicker photometry.<ref name="Leal, M 2002. pp. 351">{{cite journal | last1=Leal | first1=Manuel | last2=Fleishman | first2=Leo J. | title=Evidence for habitat partitioning based on adaptation to environmental light in a pair of sympatric lizard species | journal=Proceedings of the Royal Society of London. Series B: Biological Sciences | publisher=The Royal Society | volume=269 | issue=1489 | date=2002-02-22 | issn=0962-8452 | doi=10.1098/rspb.2001.1904 | pages=351–359| pmid=11886622 | pmc=1690909 }}</ref>

===Evolution===
''Anolis'' lizards have emerged to be a good example of [[adaptive radiation]]. The difference in dewlap morphology among ''Anolis'' lizard populations demonstrates this phenomenon. ''Anolis'' lizards have the ability to adapt to different areas of the environment in a way where multiple species can coexist effectively. The amount of vegetation in an environment affects the amount of light absorbed. Studies have shown that lighting affects the dewlap’s function as a visual signal. The diversity in vegetation in ''Anolis'' lizards’ environments has caused a similar diversity in dewlap morphology, as different species of anoles adapt to the lighting conditions in their environment.<ref name="Leal, M 2002. pp. 351"/> The ability for a lizard to signal effectively also means it is able to defend its territory and attract mates more effectively, making it a good competitor.

The relationship between background contrast and visual signals also suggests that there exists a [[coevolution]] between the signals and sensory systems of ''Anolis'' lizards.<ref>{{cite journal | last1=Leal | first1=Manuel | last2=Fleishman | first2=Leo J. | title=Differences in Visual Signal Design and Detectability between Allopatric Populations of''Anolis''Lizards | journal=The American Naturalist | publisher=University of Chicago Press | volume=163 | issue=1 | year=2004 | issn=0003-0147 | doi=10.1086/379794 | pages=26–39| pmid=14767834 | s2cid=5650723 }}</ref> The environmental diversity of Anolis habitats causes a diversity in the recognition of individuals. Sensory systems must be able to effectively pick up on dewlap signals, thus coevolving with the changes in dewlap characteristics.

One of the main limitations to these theories is that of [[gene flow]]. Population genetic theory says that gene flow can counteract evolutionary adaptations made and prevent signal divergence, due to an influx of abnormal alleles into the new population.<ref>{{cite journal | last1=Dieckmann | first1=Ulf | last2=Doebeli | first2=Michael | title=On the origin of species by sympatric speciation | journal=Nature | publisher=Springer Science and Business Media LLC | volume=400 | issue=6742 | year=1999 | issn=0028-0836 | doi=10.1038/22521 | pages=354–357| pmid=10432112 | bibcode=1999Natur.400..354D | s2cid=4301325 | url=http://pure.iiasa.ac.at/id/eprint/5926/1/IR-99-013.pdf }}</ref> This causes a genetic homogenization and challenges the idea that dewlap morphology in ''Anolis'' lizards and their sensory systems have coevolved.

==References==
{{Reflist|3}}

==Further reading==
*{{cite book|last=Losos|first=Jonathan B.|title=Lizards in an evolutionary tree: ecology and adaptive radiation of anoles|year=2011|publisher=University of California Press|isbn=9780520269842|url=http://www.ucpress.edu/book.php?isbn=9780520269842}}

== External links ==
{{Commons}}
{{Wikispecies}}
* [http://www.anoleannals.org/ Anole Annals], a blog written and edited by scientists who study ''Anolis'' lizards
* [http://reptile-database.reptarium.cz/search.php?submit=Search&exact=genus&genus=Anolis ''Anolis''], The Reptile Database
* [http://vimeo.com/75358313 Adapting Anolis], short film on adaptations of Cuba's ''Anolis'' lizards

{{Taxonbar|from=Q311348}}
{{Authority control}}

[[Category:Anoles|A]]
[[Category:Lizard genera]]
[[Category:Taxa named by François Marie Daudin]]
[[Category:Fauna of the Dominican Republic]]