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A comparative display analysis of three sibling species of Anolis lizards from HispaniolaGladson, Nancy L. January 1982 (has links)
The display repertoires of three sibling species of Anolis lizards, were quantitatively analyzed and described. These species are distributed along Haiti's western coast with no major geographic barriers separating their populations. Anolis websteri is the northernmost species, Anolis caudalis is centrally located, and Anolis brevirostris is the southernmost species. Except for contrasting dewlap color at the species contact zones, they are identical in physical appearance.
Behavioral mechanisms have been implicated in the reproductive isolation of the species. Because the head bob displays consistently incorporate the dewlap and are important in anoline communication, they may be the focal point of this isolation. This study documents a species-unique display repertoire for each of the siblings and thereby supports this hypothesis. Analysis of 736 head bob displays revealed that each species possesses one stereotyped Type A display and one to three stereotyped B displays (A. caudalis, one; A. brevirostris, two; A. websteri, three). Each species' A display resembled that of its siblings, however, discriminant analysis procedure clearly discriminated between the three species' A displays. This procedure also demonstrated differences between the Type B displays.
The six kinds of Type B displays in the combined repertoires were considered derived from one B display pattern. An interpretation of the evolutionary sequence of these patterns is provided in a cladogram in which the A. caudalis display was considered the outgroup. The cladogram shows the three displays of A. websteri are the most apomorphic and the two displays of A. brevirostris the most plesiomorphic. / Master of Science
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Home range and activity in a Virginia population of Sceloporus undulatusPreston, Karen Elizabeth January 1983 (has links)
A study of the lizard Sceloporus undulatus, conducted 1981-82 at an abandoned coal mine in Virginia, was designed to determine whether home range size, home range overlap, and patterns of behavior reflected the requirements of polygyny. The lizards were seen most often on the piles of debris that characterized the study site.
Home range size was most strongly influenced by the debris pile size. Mean home range sizes (MCP, N≥5) were 69.3 m² and 59.9 m² for adult males and females, respectively, when data for all debris piles were pooled.
The average overlap of home ranges for both study areas and for both years was 32% among adult females and 56% between adult males and females. No overlap among adult males was observed. Adult males usually associated with more than one female.
Display frequency (push-ups) and total distance moved during 20 min observation periods were higher for adult males than adult females. Jiggling (rapid head nodding) was observed only in males. The frequencies of other behaviors (e. g. prey capture) did not differ between the sexes. Only one activity, substrate licking by males, seemed to decrease significantly as a function of date.
Male home range owners interacted socially with females during the post-reproductive period. This behavior may increase a male's mating success the following spring, as most adult males that appeared on the study site during the mating season in 1982 had been home range owners in 1981. / M.S.
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Aspects of the thermal ecology of the group-living lizard, Cordylus cataphractus : a spatial and temporal analysisTruter, Johannes Christoff 03 1900 (has links)
Thesis (MSc (Botany and Zoology))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: Thermal ecology is a central theme in reptilian biology because of the thermodynamic rate
dependence of virtually all biological processes in these ectothermic animals.
Thermoregulation includes active processes (with associated energetic costs related to
altered behaviour and physiology) functioning to maintain body temperatures within a
preferred temperature range, so that the majority of physiological functions occurs optimally,
despite natural variation in the animal’s thermal habitat. The recent development of
quantitative thermal indices now allows researchers to describe the thermal habitat and
thermoregulatory functioning of an ectotherm within its environment from a cost-benefit
perspective. The use of such quantitative biophysical approaches to reptile thermal ecology
studies is however limited in the African context. Cordylus cataphractus is one of the best
studied cordylids, and exhibits various characteristics atypical for the family, such as
permanent group-living, seasonally lowered surface activity, a low resting metabolic rate and
large fat bodies. These characteristics are generally thought to be associated with groupliving
in a semi-arid habitat, yet, the possible links to thermal ecology remains unexplored.
The objectives of the current study was: firstly, to characterize the preferred
temperature range (Tp) of C. cataphractus through the use of ecologically realistic laboratory
thermal gradients; secondly, to explore seasonal and geographical variation in thermal
preference, by comparing Tp among individuals captured from a coastal and inland
population and during different seasons (autumn and spring); thirdly, to describe the thermal
habitat of a C. cataphractus population during summer, autumn, winter and spring and to
then relate these findings to the seasonal activity patterns reported in literature for the
species; fourthly, to describe the seasonal patterns of thermoregulation (during summer,
autumn, winter and spring) in a C. cataphractus population through quantitative
thermoregulatory indices; fifthly, to assess geographic variation in the thermal habitat and
IV
associated patterns of thermoregulation in C. cataphractus among a coastal population
(western range limit) and an inland population (eastern range limit). The thermal habitat of C.
cataphractus was described by measuring operative environmental temperatures (Te) with
hollow copper lizard models placed around rocks according to the natural surface movement
patterns of the species. Variation in thermal habitat quality was subsequently calculated (de
= |Te – Tp|) and averaged. Field body temperatures (Tb) of lizards were measured with
dorsally attached miniature temperature loggers. Thermoregulatory indices were calculated
from Te, Tb and Tp, describing: thermoregulatory accuracy, the effectiveness of
thermoregulation and thermal exploitation for each population (coastal and inland) for the
respective sampling periods.
The preferred body temperature range of C. cataphractus is the lowest recorded
among cordylids to date (mean Tp = 29.8oC) and was conserved among different populations
and within these populations among seasons, despite the fact that environmental
temperatures are known to vary geographically and seasonally.
Thermal habitat quality varied significantly at micro spatial scale around rocks in the
coastal population. Since C. cataphractus males are territorial, competition for thermal
habitat quality around rocks may therefore occur. Such effects will be a function of the time
of year since the variability in thermal habitat quality among rock aspects (around rocks)
varied seasonally.
Thermal habitat quality of crevices varied among seasons and was typically higher in
the open, outside rock crevices, during the cooler winter and spring periods, whereas in
summer and autumn the crevice environments were more favourable. Thermal habitat
quality was high in crevices during autumn, suggesting that the observed repressed surface
activity of C. cataphractus described for the time is not necessarily, as previously thought,
only due to food constraints. Moreover, in contrast to earlier reports, the current results (Tb
versus Te) indicate that individuals emerged from crevices in summer.
The geographical assessment indicated that lizards from the coastal population, with
generally larger groups, thermoregulated more successfully than those from the inland population. The higher thermoregulatory success in the coastal population occurred in spite
of the fact that thermal habitat quality was significantly lower at the coastal locality. The
higher thermoregulatory success in the coastal population was likely due to reduced
predation risk associated with increased group-size. The seasonal trends in
thermoregulation at the coastal and inland population corresponded to the patterns predicted
by the cost-benefit model of thermoregulation, accuracy of thermoregulation and the
effectiveness of thermal exploitation being higher during the thermally more favourable
autumn. / AFRIKAANSE OPSOMMING: Uittreksel
Termiese ekologie is ‘n sentrale tema in reptiel-biologie as gevolg van die termodinamies
tempo-afhanklikheid van feitlik alle biologiese prosesse in hierdie ektotermiese diere.
Termoregulering sluit aktiewe prosesse (wat lei tot energie-koste in terme van gedrag en
fisiologie) in om liggaamstemperature binne ‘n vasgestelde voorkeurtemperatuur-reeks te
handhaaf sodat fisiologiese prosesse optimaal kan geskied te midde van natuurlike variasie
in die dier se termiese omgewing. Die onlangse ontwikkeling van kwantitatiewe funksionele
termiese indekse stel navorsers nou in staat om die werklike termiese omgewing en die
funksionering van die ektoterm binne sy omgewing te beskryf en uit ‘n koste (energie)-
voordeel oogpunt te verstaan. Die gebruik van hierdie biofisiese koste-voordeel benadering
in reptiel termoreguleringstudies is egter beperk in die Afrika-konteks. Cordylus cataphractus
is een van die bes bestudeerde lede van familie Cordylidae, en vertoon verskeie eienskappe
ongewoon vir hierdie groep akkedisse, soos groeplewendheid, beperkte seisoenale aktiwiteit
buite hul skeure, ‘n relatiewe lae rustende metaboliese tempo en relatiewe groot vetliggame.
Hierdie unieke eienskappe is al deur navorsers gekoppel aan die groeplewe lewensstrategie.
Die potensiële koppeling van die termiese ekologie en die spesifieke lewensstrategie
van C. cataphractus benodig verdere studie. Die doelwitte van hierdie studie was
eerstens: om die voorkeurtemperatuur-reeks (Tp) van C. cataphractus te bepaal deur van
ekologies-realistiese termiese gradiënte in die laboratorium gebruik te maak; tweedens: om
geografiese en seisoenale variasie in Tp te ondersoek deur individue te gebruik wat uit
binnelandse en kus-populasies, tydens verskillende seisoene, herfs en lente versamel is;
derdens: om die termiese omgewing, meer spesifiek die variasie in termiese kwaliteit, binne
die habitat van C. cataphractus populasie in verskillende seisoene, somer, herfs, winter en
lente, te moduleer en met die gedokumenteerde aktiwiteitspatrone in verband te bring;
vierdens: om die seisoenale temoreguleringspatrone (tydens somer, herfs, winter en lente)
van C. cataphractus populasie te beskryf; vyfdens: om geografiese variasie in die termiese
habitat en geassosieerde termoreguleringspatrone tussen kus-populasie (westelike
VII
verspreidingsgrens) en binneland-populasie (oostelike verspreidingsgrens) te bestudeer.
Die kwaliteit van die termiese habitat van C. cataphractus is bepaal deur hol koper-modelle
van akkedisse (operatiewe temperatuur modelle (Te)) te plaas rondom rotse in
ooreenstemming met die natuurlike bewegingspatrone van die akkedisse. Die termiese
kwaliteit is gevolglik afgelei (de = |Te – Tp|) en gemiddeldes bereken. Die
liggaamstemperature (Tb) van vrylopende akkedisse in die veld is met dorsaal-gemonteerde
miniatuur temperatuur “data-loggers” gemeet. Termiese indekse (deur Te, Tb en Tp te
gebruik) is bereken om die akkuraatheid en effektiwiteit van termoregulering, sowel as
termiese benutting van die omgewing vir beide populasies (kus en binneland) tydens
verskillende seisoene te beraam.
Die voorkeurtemperatuur-reeks van C. cataphractus is die laagste gedokumenteerde
temperature vir enige lid van die familie Cordylidae tot op hede bestudeer (gemiddeld van Tp
= 29.8oC), en het ten spyte van die feit dat omgewingstemperature wissel op geografiese en
seisoenale vlakke, min gevarieer tussen die twee populasies asook tydens verskillende
seisoene binne die populasies.
Die termiese kwaliteit het beduidend gevarieer tussen seisoene en binne die mikroruimtelike
omgewing rondom rotse in die kus-populasie. Aangesien C. cataphractus
mannetjies territoriaal is, word die aanname gemaak dat kompetisie vir ‘n ruimtelike posisie
ook ‘n termiese koste mag hê aangesien daar beduidende variasie in de om die rotse was.
Variasie in termiese kwaliteit rondom rotse was verder ook funksie van die tyd van die jaar
(seisoene).
Die termiese kwaliteit van skeure het gevarieer tussen seisoene, en termiese
kondisies/toestande was oor die algemeen meer gunstig buite die rots-skeure tydens die
koeler winter en lente tydperke, terwyl skeure termies meer gunstig was in die somer en
herfs maande. Termiese habitat kwaliteit van skeure was besonders hoog gedurende die
herfs, en die voorspelling is dus dat die verlaagde oppervlak-aktiwiteit wat gedurende hierdie
tyd van die jaar vir C. cataphractus gedokumenteer is nie noodwendig funksie van
beperkte voedselbeskikbaarheid is nie. Teenstrydig met gepubliseerde aktiwiteitsrekords dui die resultate (Tb teenoor Te) verder daarop dat individue wel uit skeure kom tydens die warm
somer seisoen.
Die geografiese ondersoek het gewys dat akkedisse van die kus-populasie (wat
gewoonlik uit groter groepe bestaan), meer akkuraat getermoreguleer het as akkedisse van
die binneland-populasie. Die hoër akkuraatheid van termoregulering in die kus-populasie is
bewerkstellig ten spyte van die feit dat die termiese kwaliteit beduidend laer was as die van
die binneland-populasie. Die hoër termoreguleringsakkuraatheid in die kus-populasie kan
waarskynlik toegeskryf word aan laer predasie-risiko geassosieer met groter groepe. Die
seisoenale variasie-patroon van termoregulering kan verklaar word deur die koste-voordeel
model van termoregulering, waarvolgens die akkuraatheid van termoregulering sowel as
termiese benutting hoër is tydens periodes van hoë termiese kwaliteit (i.e. herfs).
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Fossil lizards (squamata,reptilia) from the early Pleistocene of Cooper's Cave (South Africa): taxonomy and further implications for the herpetofaunal studies of the plio-pleistocene sites from the Cradle of HumankindVilakazi, Nonhlanhla 01 July 2014 (has links)
South Africa is well known for its many, important fossil bearing deposits of Plio-Pleistocene age. Many of these sites contain abundant remains of extinct and extant animals including hominins. Non-herpetological fauna have been used to reconstruct important information about past environments and for chronological data. This study tried a different method; using herpefauna to establish past environments of Cooper’s Cave. Herpetological fauna potentially have numerous advantages in their use for such questions, including typically limited ranging behaviors, and specific temperature requirements. Despite these advantages only a few studies have even mentioned the presence of squamate fauna in the fossil assemblages of these sites.
This study has demonstrated that herpefauna exists, in reasonable levels of abundance and with adequate preservation within the fossil record of the dolomitic region now known as the Cradle of Humankind. It has also demonstrated for the first time the presence of a relative abundance of herpefauna at numbers far greater than any previous study has recognized. The present study was however, handicapped in not being able to fully utilize the material at hand to interpret past environments, owing to the lack of comparative material needed to move beyond the family or generic level in most cases with any degree of confidence. However, Agamids and Pseudocordylids were described to generic level.
However, the many shortcomings that this work highlighted should not be seen as reason not to pursue the study of herpefauna, but to improve present comparative collections and collecting methods around the fossils themselves.
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Food Choice, Reinforcer Preference, and Visual Discrimination in Monitor Lizards (Varanus Spp.)Gaalema, Diann Ellen 23 October 2007 (has links)
Learning in reptiles has been studied with a variety of methods and included numerous species. However, research on learning in lizards has generally focused on spatial memory and has used only a few species. No research has specifically investigated and documented the use of visual discrimination in monitor lizards. The ability of monitor lizards (Varanus spp.) to discriminate between visual stimuli was investigated. Subjects were tested on acquisition and two reversals of a discrimination task between black and white stimuli. A food-choice procedure was used to determine if consistent rankings of food items could be determined using a multiple-stimulus choice procedure. The functional value of the rankings was assessed using a progressive ratio technique. The subjects formed stable food preferences, which were reflected in increased response requirement completed for preferred items and subjects did successfully learn the initial discrimination task and the following reversals.
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Seasonal regulation of the circadian rhythms of behavioural temperature selection and locomotor activity in Australian sleepy lizards (Tiliqua rugosa, gray; reptilia: scincidae)Ellis, David John January 2010 (has links)
This research project examined the role of environmental time cues and circadian rhythms in mediating seasonal adjustments in the body temperature and locomotoractivity patterns in the Australian sleepy lizard, Tiliqua rugosa (Gray 1827). The first component of this study investigated whether daily rhythms of behavioural thermoregulation and locomotor activity that T. rugosa displays in the field are endogenous circadian rhythms. In each season, there was significant variation in each of these rhythms in lizards released on laboratory thermal gradients under prevailing light-dark (LD) cycles. Both rhythms persisted when lizards were released in constant darkness (DD) and exhibited the same free-running period suggesting a single circadian pacemaker drives both rhythms. The first component of this study revealed that seasonal changes in the expression of daily behavioural thermoregulatory and locomotor activity rhythms are mediated by the circadian system in T. rugosa. The second component of this project comprised three experiments that determined the relative importance of 24 h LD and temperature cycles (TCs) in entraining the locomotor activity rhythm. In the first experiment, lizards were held under LD 12:12 and were subjected to either a TC of 33:15C in phase with the LD cycle or a reversed TC. Following LD 12:12, lizards were maintained under the same TCs but were subjected to DD. Activity was restricted to the thermophase in LD irrespective of the lighting regime and during the period of DD that followed, suggesting entrainment by the TC. In the second experiment, lizards were held under LD 12.5:11.5 and were subjected to one of three treatments; (1) constant 30C, (2) normal TC (30:20C), or (3) reversed TC. Following LD, all lizards were subjected to DD and constant 30C. Post-entrainment free-run records revealed that LD cycles and TCs both entrain locomotor activity rhythms of T. rugosa. Although there was large variation in the phasing of the rhythm in relation to the LD cycle in reversed TC lizards, TCs presented in phase with the LD cycle most accurately synchronised the rhythm to the photocycle. In the third experiment, lizards were held in DD at constant 30C before being subjected to a further period of DD and one of four treatments; (1) normal TC (06:00 h to 18:00 h thermophase), (2) delayed TC (12:00 h to 00:00 h thermophase), (3) advanced TC (00:00 h to 12:00 h thermophase) or (4) control (no TC, constant 30C). While control lizards continued to free-run in DD at constant temperature, locomotor rhythms of lizards subjected to TCs rapidly entrained to TCs irrespective of whether TCs were phase advanced or delayed by 6 h. The results of this experiment excluded the possibility that masking effects were responsible for locomotor responses of lizards to TCs. This study demonstrated that seasonal changes in the expression of this species‟ daily behavioural thermoregulatory and locomotor rhythms are mediated by a circadian system that is sensitive to both light and temperature. The sensitivity of the circadian system to temperature, in particular, may allow T. rugosa to restrict its activity to times of the year that are thermally favourable. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1521959 / Thesis(Ph.D.)-- University of Adelaide, School of Medical Sciences, 2010
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Woody debris and the effect on the predicted probability of lizard capture in Arcoona Creek, Gammon Ranges National Park, South Australia /Coventry, Ben January 1998 (has links) (PDF)
Thesis (Env. Mgt.(Hons.))--University of Adelaide, Dept. of Environmental Science and Management, 1998. / Bibliography: leaves 52-58.
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Thermal and reproductive biology of the lizards sceloporus occidentalis and sceloporus graciosus along an environmental and geographical gradientParker, Scott Landsborough 01 January 2001 (has links)
The thermal environment exerts a strong influence on many aspectsof squamate life history. Environmental temperatures constrain daily activity time, fecundity, growth rate, and also influences hatchling phenotype. Cold nest temperatures can slow the development of eggs deposited in the soil, cause developmental abnormalities or result in mortality of embryos.
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The phylogeography of the southern rock agama (Agama atra) in the Cape Fold Mountains, South AfricaSwart, Belinda 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: An understanding of the phylogeography and evolutionary processes involved in
speciation is essential for the conservation and management of any particular
species. To investigate the phylogeographic patterns in Agama atra from the Cape
Fold Mountains (CFM), 98 individuals from 38 geographically close localities
were analysed. In addition, to understand the phylogeographic associations
between the CFM populations and the rest of Southern Africa, 18 specimens from
12 localities outside the CFM were also included. A total of 988 characters
derived from two mitochondrial DNA fragments (control region and ND2)
revealed 59 distinct haplotypes in the CFM. Parsimony, Bayesian and maximum
likelihood analyses revealed four distinct clades associated with geography within
the CFM. These clades were supported by a haplotype network and were defined
as the Cape Peninsula clade, the Limietberg clade, the northern CFM clade and
the central CFM clade. Analysis of molecular variance confirmed the high degree
of genetic structure within the CFM, with more than 75% of genetic variation
found among the geographic areas. SAMOVA and nested clade analysis (NCA)
suggest that the central CFM clade may be more diverse than detected by the
networks and the phylogenetic analyses. The processes that caused the four
distinct genetic groups in the CFM are not yet clear. Using a speculative
molecular clock estimate, the main cladogenesis of A. atra within the CFM took
place, approximately ~6.5 - 9 MYA. This dating coincides well with the
documented Miocene-Pliocene climate fluctuations which might have contributed
towards the isolation among lineages. The genetic structure found in A. atra is
also markedly congruent with what has been found in other taxa such as Mesamphisopus spesies, Potamonautes brincki, and Pedioplanis burchelli and
this would further support vicariance as a main isolating factor here. / AFRIKAANSE OPSOMMING: ‘n Goeie begrip van die filogeografie en die evolusionêre gebeurtenisse wat
verband hou met spesiasie is belangrik vir die bewaring en bestuur van enige
spesie. Om die filogeografiese patrone in Agama atra van die Kaapse Plooiberge
(KPB) te ontleed, was 98 individue van 38 nabygeleë lokaliteite geanaliseer.
Tesame met bogenoemde monsters was 18 individue van 12 lokaliteite van buite
die KPB ook geanaliseer om die filogeografiese verwantskappe tussen die KPB
bevolkings en die res van Suidelike Afrika te ondersoek. Uit ‘n totaal van 988
karakters verkry uit twee mitochondriale DNS fragmente (die kontrole gebied en
ND2) is 59 haplotipes gevind. Parsimonie en modelgebaseerde filogenetiese
analises dui daarop dat vier groepe geassosieer met geografie binne die KPB
voorkom. Die groepe word geondersteun deur ‘n haplotipe netwerk en word soos
volg gedefinieer: ‘n Kaapse Peninsula groep, ‘n Limietberg groep, ‘n noordelike
KPB groep en ‘n sentrale KPB groep. Analises van molekulêre variansie
(AMOVA) bevestig die hoë graad van genetiese struktuur binne die KPB, met
meer as 75% genetiese variasie gevind tussen die geografiese areas. SAMOVA en
gesetelde groep analises (“NCA”) stel voor dat die sentrale KPB groep dalk meer
variasie vertoon as wat die netwerk en filogenetiese analises vertoon. Die prosesse
wat die vier genetiese groepe tot stand gebring het is nog nie bekend nie. Volgens
‘n spekulatiewe molekulêre klok berekening het die hoof kladogenese van A. atra
binne die KPB ongeveer ~6.5 - 9 miljoen jaar (MJ) gelede plaasgevind. Hierdie
datering stem goed ooreen met die gedokumenteerde Mioseen-Plioseen klimaat
veranderinge wat isolasie van die groepe kon bewerkstellig het. Die genetiese
struktuur van A. atra in the KPB is ook gevind in ander taksa soos Mesamphisopus spesies, Potamonautes brincki, en Pedioplanis burchelli en
bevestig dus dat vikariansie hier die hoof faktor vir isolasie is.
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Molecular phylogenetics and phylogeography of sand lizards, Pedioplanis (Sauria: Lacertidae) in southern AfricaMakokha, Jane Sakwa 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The present study aims to determine the phylogenetic relationships among the sand lizards, Pedioplanis. In addition, a single mitochondrial gene is used to investigate the geographic genetic structure of the widey distributed P. burchelli. With 11 species, Pedioplanis is the most speciose genus among the southern African genera of the family Lacertidae. All the species are restricted to the subcontinent with the exception of three (P. namaquensis, P. undata and P. benguellensis), which extend their range northwards into Angola. A total of 2200 nucleotide positions derived from two mitochondrial markers (ND2 and 16S rRNA) and one nuclear gene (RAG-1) are used to determine the phylogenetic relationships among ten of the eleven Pedioplanis species. The first well resolved gene tree for the genus, drawn from 100 individuals, is presented and this is largely congruent with a phylogeny derived from morphology. Contrary to some previous suggestions, Pedioplanis forms a monophyletic assemblage with Heliobolus and Nucras. The genus Pedioplanis is monophyletic with P. burchelli/P. laticeps forming a sister clade to all the remaining congeners. Two distinct geographic lineages can be identified within the widespread P. namaquensis; one occurs in Namibia, while the other occurs in South Africa. The “P. undata” species complex is monophyletic, but one of its constituent species, P. inornata, is paraphyletic. Relationships among the subspecies of P. lineoocellata are much more complex than previously documented. An isolated population previously assigned to P. l. pulchella is paraphyletic and sister to the three named subspecies. The phylogeny identifies two biogeographical groupings that probably diverged during the mid-Miocene. The development of the Benguella Current could have initiated isolation mechanisms associated with changes in habitat that could have generated barriers and played a role in the evolution of this group.
At the lower taxonomic level, the mtDNA phylogeographic structure of the wide spread P. burchelli in South Africa reveal at least six distinct clades that are geographically partitioned. The first one is restricted to the eastern mountains along the Great Escarpment (GE). The next three are found along the Cape Fold Mountains (CFM): the north-west CFM, central CFM and eastern CFM. The fifth one shares samples from central CFM and GE. The last clade is restricted to the eastern central mountains of the GE. These six geographic groupings are genetically divergent from each other and they started separating in the early Pliocene period. Phylogeographic studies on other taxa in the region have found different levels of genetic structuring among or within taxa. The fact that P. burchelli is restricted to high altitude areas could have resulted in limited dispersal and consequently contributed to its geographic structure. However, the exact cause of the pattern obtained is not readily apparent. Habitat fragmentation in the past is probably one of the most influential factors shaping the genetic distribution of the species across South Africa. The inclusion of nuclear markers will shed more light on the evolutionary history of P. burchelli in South Africa. / AFRIKAANSE OPSOMMING: Die huidige studie stel ten doel om ‘n filogenie daar te stel vir die Sand akkedisse, Pedioplanis. ‘n Enkele mitochondriale geen is ook gebruik om die geografiese genetiese struktuur van die wydverspreide P. burchelli vas te stel. Met 11 spesies is Pedioplanis die mees spesieryke genus onder die suidelike Afrika genera wat aan die Lacertidae familie behoort. Al die spesies is beperk tot die subkontinent met die uitsondering van drie (P. namaquensis, P. undata en P. benguellensis), wat ‘n uitgebreide verspreiding het noordwaarts tot in Angola. ‘n Totaal van 2200 nukleotied posisies wat afkomstig is van twee mitochondriale merkers (ND2 en 16S rRNA) en een nukluêre geen (RAG-1) is gebruik om die filogenetiese verwantskappe tussen 10 van die 11 Pedioplanis spesies vas te stel. Die eerste goed geondersteunde geen boom vir die genus, gebasseer op 100 individue, is verkry en dit is meestal ooreenstemmend met ‘n filogenie gebasseer op morfologie. In teenstelling met sekere voorstelle van die verlede vorm Pedioplanis ‘n monofiletiese groep tesame met Heliobolus en Nucras. Die genus Pedioplanis is monofileties met P. burchelli/P. laticeps wat ‘n suster groep vorm van al die oorblywende lede van die genus. Twee herkenbare geografiese lyne kan geidentifiseer word in die wydverspreide P. namaquensis; een kom in Namibia voor, terwyl die ander een in Suid Afrika voorkom. Die “P. undata” spesies kompleks is monofileties, maar een van die spesies wat deel uitmaak van die groep, P. inornata, is parafileties. Verwantskappe tussen die subspesies van P. lineoocellata is meer kompleks as wat aanvanklik aanvaar is. ‘n Geisoleerde bevolkimg wat voorheen toegesê is aan P. l. pulchella is parafileties en verteenwoordig ‘n suster groep van die benaamde subspesies. Die filogenie identifiseer twee biogeografiese groeperings wat moontlik gedivergeer het gedurende die middel-Miocene. Die ontwikkeling van die Benguella stroom het dalk versperrings geinisiëer as gevolg van die gesamentlike veranderinge in habitat wat dalk ook ‘n rol gespeel het in die evolusie van die groep.
Op die laer taksonomiese vlak het die mtDNA filogeografiese struktuur van die wydverspreide P. burchelli in Suid Afrika ten minste ses groepe aangetoon wat geografies van mekaar geskei is. Die eerste een is beperk tot die oostelike berge wat aan die Groot Eskarpement (GE) behoort. Die volgende drie word gevind in die Kaapse Vouberge (KVB): die noord-westelike KVB, sentrale KVB en oostelike KVB. Die vyfde een deel eksemplare van beide die GE en die KVB. Die laaste groep is beperk tot die oostelike en sentrale berge van die GE. Hierdie ses geografiese groepe is geneties geskei van mekaar en hulle het begin om apart te ontwikkel gedurende die vroë Pliocene periode. Ander filogeografiese studies in die area het verskillende vlakke van genetiese struktuur vertoon tussen en binne taksa. Die feit dat P. burchelli beperk is tot hoogliggende dele kon moontlik bygedrae het tot die geografiese struktuur. Die presiese oorsaak van die patroon wat verkry is, is nie ooglopend nie. Habitat fragmentasie in die verlede is moontlik een van die mees invloedrykste faktore wat die genetiese verspreiding van die spesie in Suid Afrika beinvloed het. Die insluiting van nukluêre merkers sal meer lig warp op die evolusionêre geskiedenis van P. burchelli in Suid Afrika.
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