Tail length variation inMacaca fascicularis andM. mulatta

Based on collectors' measurements of 1,040 specimens, variation of relative tail length [RTL = (tail length/head and body length) × 100] has been studied inMacaca fascicularis andM. mulatta, two closely related species that replace one another in tropical Asia and subtropical Asia, respectively. RTL usually is greater than 90 inM. fascicularis and usually is less than 60 inM. mulatta; intermediate values occur in only 3.5% of specimens studied. Within each species, RTL is approximately equal in females and males. From infancy to adulthood, RTL tends to decline in both species. InM. fascicularis, RTL generally decreases with increasing latitude; inM. mulatta, RTL is approximately constant latitudinally. Where the geographic ranges of these two species meet at ca. 15°N in the Indochinese Peninsula, a few specimens have been collected in which RTL and dorsal pelage color are intermediate between those inM. fascicularis andM. mulatta. The observed pattern of variation suggests that the ranges ofM. fascicularis andM. mulatta formerly were separated by a zoogeographic barrier — perhaps during a Pleistocene glacial interval. After disappearance of the postulated barrier, the ranges of these two species apparently became contiguous and limited hybridization has occurred.     

Heart rate patterns under stress in three species of macaques

Cardiac responses during one hour exposures to three stressful experimental conditions were compared among juvenile females of three species of the genus Macaca (M. mulatta, M. radiata, and M. fascicularis). M. fascicularis showed the highest overall heart rate, and M. mulatta the lowest, in all three conditions. The principal difference between species was in the pattern of change in heart rate over the test sessions. Heart rate declined during the hour for all three species in the first two conditions (home cage novel environment), and the change was most rapid in M. mulatta and slowest in M. fascicularis. In the third and most stressful condition (physical restraint), each species showed a distinct temporal pattern. Heart rate increased over the hour in M. fascicularis, declined in M. radiata, and increased rapidly then declined gradually in M. mulatta. Individual differences in heart rate tended to be consistent within and across conditions. Correlations between behavioral measures of somatic activity and heart rate were generally modest. The results are in accord with other behavioral and physiological differences obtained for the same subjects, and suggest that responses to environmental stimuli reflect fundamental aspects of temperament that may vary substantially even among closely related species. © 1994 Wiley-Liss, Inc.     

The complex relationship between behavioral attributes,social status,and whole blood serotonin in male Macaca fascicularis

Among group-housed male Cercopithecus aethiops, dominant animals have higher concentrations of whole bood serotonin (WBS) than their subordinate counterparts. In contrast, there appears to be no relationship between social status and WBS in Macaca nemestrina. We report here the relationship between social status and WBS among 29 male Macaca fascicularis housed in groups of five. Membership in these groups was disrupted periodically (20 times in 26 months) with a reorganization manipulation. Concentrations of WBS were assessed just prior to the 20th (final) social reorganization and at 1, 2, and 5 weeks following that reorganization. Correlations between these repeated samples were high, indicating considerable intraindividual stability in WBS. Overall, there were no persistent differences in WBS between clearly dominant (ranked 1 or 2) and subordinate (ranked 3, 4, or 5) monkeys, despite the substantial behavioral differences between such animals and the stability of social status across time. A multivariate analysis indicated that WBS was best predicted by a model that included a positive relationship with the interaction between rate of grooming and social status (P < 0.002), a negative relationship with extreme aggressiveness (P = 0.03), and a positive relationship with time spent alone (P < 0.04). Further analysis of the social status by grooming rate interaction revealed that WBS was higher in dominants than subordinates, but only if the dominants also initiated grooming frequently. These differences in the relationship WBS and social status in C. aethiops and M. fascicularis may reflect differences in the behavioral dynamics underlying the dominance hierarchies in small groups of these two species.     

Intra- and interspecific variation in body size ofProtohermes (Megaloptera: Corydalidae)

The life history of three populations ofProtohermes grandis and two populations ofProtohermes immaculatus (Megaloptera: Corydalidae) was compared. In general, the larvae lived in stream riffles for 2 years and the adults appeared in summer. Adult body size differed between these closely related species and also between the populations ofP. grandis. Dwarfism occurred inP. immaculatus, a species that is endemic to the small, isolated island, Amami Island. The population ofP. grandis on Yaku Island, located between Amami Island and the mainland Kyushu, had an intermediate body size between that ofP. immaculatus and the mainland population ofP. grandis. Despite being an insular population,P. grandis on Tsushima Island had a similar body size to mainlandP. grandis. In these populations with large adults, some larvae lived in the streams for 3 years. The size distribution of benthic animals, which are the prey available toProtohermes larvae, differed between the streams studied. The density of large prey was lowest on Amami Island, intermediate on Yaku Island, and highest on the mainland and Tsushima Island. Different size distributions of available prey may be caused by the differences of benthic fauna; most of Ecdyonuridae and Ephemerellidae (large mayflies) and Perlidae (large stoneflies) were not found on Amami and Yaku Islands. Thus, there is a tendency to dwarfism in the populations ofProtobermes inhabiting streams where the density of large prey is low.     

Size‐dependent insect flight energetics at different sugar supplies

Under most circumstances, large body size confers a higher fitness and is positively selected, whereas selection against large size is empirically poorly documented. Physiologically, according to the ¾ power law, larger animals have lower relative but higher absolute energy demands, such that large body size may become disadvantageous, particularly under fast locomotion in food‐limited environments. After a period of initial feeding on different sugar concentrations, we investigated size‐dependent energy content (reserves) at baseline and of females unflown (i.e. resting) or flown for 18 h in two (replicate) insect species: the yellow dung fly Scathophaga stercoraria and the yellow fever mosquito Aedes aegypti. Tethered adults of various sizes were tested in a flight mill. In both species, teneral glycogen, sugar, and lipid content increased with sugar availability, and isometrically or even hyper‐allometrically (slope > 1) with body size. Activity treatment also revealed the expected consumption effects. Both species increased their flight distance with sugar supply, although only larger mosquitoes flew longer. Crucially, larger females of both species disproportionately exhausted more glycogen and sugars (but not lipid) during flight. The mosquitoes appeared to adjust their flight more finely to their size‐dependent energy reserves at all sugar availabilities, whereas, in the dung flies, size‐dependent energy demands were detectable only with a low but not with an overly high sugar supply. Although we found a greater absolute and relative locomotory energy demand for the larger flies, which is in agreement with interspecific patterns in insects, this was (more than) compensated by their greater baseline energy reserves, resulting in the greater net flying capacity of larger individuals. Consequently, we found no evidence for energetic mechanisms limiting the performance of large flying insects under food limitation. The differences between the two species presumably relate to mosquitoes inherently being long distance flyers and dung flies being short distance flyers. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ●● , ●●–●●.     

A comparison of the behavior of Macaca fascicularis and Macaca mulatta in relation to the menstrual cycle

Observations on oppositely sexed pairs of M. fascicularis and M. mulatta revealed certain differences. M. fascicularis showed single-mount copulations, higher potency, less grooming activity, and milder but more frequent aggressive exchanges than the rhesus monkey. These differences might be due to the lower dominance gradient between the sexes and less sexual dimorphism in M. fascicularis than in M. mulatta. There were changes in the sexual, grooming, and aggressive interaction in relation to the menstrual cycle, indicating the suitability of M. fascicularis for hormone-behavior studies. Comparison of data from 30 and 60 min tests showed that important behavioral changes did not become apparent unless animals were given enough time to interact.     

Musculoskeletal scapular correlates of plantigrade and acrobatic positional activities in Papio cynocephalus anubis and Macaca fascicularis

This study investigates several musculoskeletal scapular correlates of quadrupedal behavior in predominantly plantigrade, Papio cynocephalus anubis and acrobatic, less plantigrade, Macaca fascicularis. Positional behaviors differ in these two primates reflecting the amount of time spent emphasizing one or the other of these captive behavioral regimes. Stresses associated with particular patterns of behavior result in different scapular morphologies. Papio exhibits a significantly broader scapula with a more dorsoventrally curved blade accompanying an enlarged teres major muscle. The supraspinous fossa is wider in Papio, while the infraspinous/teres major attachment is wider in Macaca. Angular measurements reflect the breadth dimension of the various fossae. These results utilize two species of primates to extend a methodology developed in previous studies and to suggest that a predictable interdependence occurs between scapular dimensions and certain behavioral activities.     

Intraspecific and interspecific variation of female genitalia in two species of watersnake

The morphological differences in female genitalia within and between species are little studied and poorly understood, yet understanding patterns of variation in female genitalia can provide insights into mechanisms of genital evolution. The present study aimed to explore the patterns of intraspecific and interspecific variation in female genitalia in two sister taxa of watersnake (Nerodia sipedon and Nerodia fasciata) that have similar genital shape. We used a geometric morphometric (GM) approach to study variation in shape of the vagina between and within two sister species. We examined genital shape in female watersnakes ranging from small, sexually immature females to large reproductive females that had recently given birth. We found that shape variation of genitalia is strongly correlated with body size, where larger but not smaller females have a bifurcation in the vagina. However, we also found significant shape variation in the structure of the vagina between the two species, where N. fasciata has narrower genitalia with more prominent bifurcation, whereas N. sipedon has wider genitalia with less marked bifurcation. Using GM allowed us to detect significant differences in genital shape that were not apparent upon visual examination alone, suggesting that shape variation in female genitalia may be greater than previously assumed. Additional study of morphological differences in male reproductive organs for these species would help to determine whether there has been genital co‐evolution, and potentially mechanical reproductive isolation, in these two closely‐related and occasionally sympatric species. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 183–191.     

Macaque Masseter Muscle: Internal Architecture,Fiber Length and Cross-Sectional Area

Models of mastication require knowledge of fiber lengths and physiological cross-sectional area (PCS): a proxy for muscle force. Yet only a small number of macaques of various species, ages, and sexes inform the previous standards for masseter muscle architecture. I dissected 36 masseters from 30 adult females of 3 macaque species—Macaca fascicularis, M. mulatta, M. nemestrina—using gross and chemical techniques and calculated PCS. These macaques have mechanically similar dietary niches and exhibit no significant difference in masseter architecture or fiber length. Intramuscular tendons effectively compartmentalize macaque masseters from medial to lateral. Fiber lengths vary by muscle subsection but are relatively conservative among species. Fiber length does not scale with body size (mass) or masseter muscle mass. However, PCS scales isometrically with body size; larger animals have greater force production capabilities. PCS scales positively allometrically with facial size; animals with more prognathic faces and taller mandibular corpora have greater PCS, and hence force, values. This positive allometry counters the less efficient positioning of masseter muscles in longer-faced animals. In each case, differences in PCS among species result from differences in muscle mass not fiber length. Masseter PCS is only weakly correlated with bone proxies previously used to estimate muscle force. Thus predictions of muscle force from bone parameters will entail large margins of errors and should be used with caution.     

The evolution of large body size in orangutans: A model for hominoid divergence

Recent Miocene fossil discoveries of large hominoids resemble orangutans. Since the evolution of large body size was functionally related to a powerful masticatory system in Miocene ape radiations, a better understanding of adaptations in extant orangutans will be informative of hominoid evolution. It is suggested here, based on the behavioral ecology of extant orangutans, that foraging energetics and large body size are tied to a dietary shift that provided access to and utilization of resources not generally available to other primates.     

Geometric characters of the radius and tibia in <Emphasis Type="Italic">Macaca mulatta</Emphasis> and <Emphasis Type="Italic">Macaca fascicularis</Emphasis>

We performed comparative analyses of four cross-sections of the distal radius and tibia in two species of macaque to clarify the relationships between bone morphology and locomotor type. The lengths of bones and five bone geometric properties in each section were examined and compared separately in both female and male Macaca mulatta and Macaca fascicularis. In M. mulatta, there were no significant gender-specific differences in either the radius or the tibia. In contrast, the radius and tibia of male M. fascicularis had greater geometric parameters in the 20% and 40% positions relative to the 5% and 10% positions from the distal end than those of their female counterparts. The radius and tibia of M. mulatta were relatively longer than those of M. fascicularis, and the sectional parameters of the tibia of M. mulatta were relatively larger than those of M. fascicularis. Standardization of the log-transformed bone length between the species revealed larger radial cortical bone areas in M. fascicularis. In contrast, there were minimal differences in the tibial cortical bone areas between the two species. This study suggests that the observed distinctions in bone geometry in female and male M. fascicularis may be due to gender-specific differences in the muscle weights of the forearm and calf, which may underlie the divergence in the leaping abilities of females and males of this species. Taken together, these results of interspecies comparisons may be related to the fact that arboreal primates such as M. fascicularis undergo compressive mechanical stress due to the forelimb lead that occurs as the animal descends a sloping trunk or bridges a tree gap downward, while terrestrial primates such as M. mulatta move on nearly flat substrates. Differences in fore- and hind-limb bone properties between the two species are discussed with regard to functional morphology and locomotor type.     

Ecogeographical and phylogenetic effects on craniofacial variation in macaques

The widespread and complex ecogeographical diversity of macaques may have caused adaptive morphological convergence among four phylogenetic subgroups, making their phylogenetic relationships unclear. We used geometric morphometrics and multivariate analyses to test the null hypothesis that craniofacial morphology does not vary with ecogeographical and phylogenetic factors. As predicted by Bergmann's rule, size was larger for the fascicularis and sinica groups in colder environments. No clear size cline was observed in the silenus and sylvanus groups. An allometric pattern was observed across macaques, indicating that as size increases, rounded faces become more elongated. However, the elevation was differentiated within each of the former two groups and between the silenus and sylvanus groups, and the slope decreased in each of the two northern species of the fascicularis group. All allometric changes resulted in the similar situation of the face being more rounded in animals inhabiting colder zones and/or in animals having a larger body size than that predicted from the overarching allometric pattern. For non‐allometric components, variations in prognathism were significantly correlated with dietary differences; variations in localized shape components in zygomatics and muzzles were significantly correlated with phylogenetic differences among the subgroups. The common allometric pattern was probably influenced directly or indirectly by climate‐related factors, which are pressures favoring a more rounded face in colder environments and/or a more elongated face in warmer environments. Allometric dissociation could have occurred several times in Macaca even within a subgroup because of their wide latitudinal distributions, critically impairing the taxonomic utility of craniofacial elongation. Am J Phys Anthropol 154:27–41, 2014. © 2014 Wiley Periodicals, Inc.     

A PHYLOGENETIC ANALYSIS OF BODY SIZE EVOLUTION AND BIOGEOGRAPHY IN CHUCKWALLAS (SAUROMALUS) AND OTHER IGUANINES

The evolution of body size was reconstructed in chuckwallas (genus Sauromalus), large herbivorous lizards of southwest North America, using a phylogeny derived from sequence variation in the mitochondrial cytochrome b gene. The body mass of two endemic island species (S. hispidus and S. varius) is typically fivefold larger than mainland species. We tested the hypothesis that large body size has evolved on these islands in response to local ecological conditions against the alternative hypothesis that large size is simply retained from large iguanine ancestors. The most parsimonious tree topology depicts the insular gigantic Sauromalus as monophyletic, having diverged from a common ancestor on the Baja California peninsula after the radiation of smaller bodied clades. In a robustness analysis of this topology, we found general support for this tree over alternative topologies representing minimum evolution hypotheses that imply large body size is retained from large iguanine ancestors. The most parsimonious reconstruction of body size evolution implies a change from large to small size after the Sauromalus ancestor diverged from Iguana, and one reversal back to large size within Sauromalus. The large size increase in the gigantic clade contrasts with evolutionary stasis of small body size (for an iguanine) in mainland populations. The gigantic species show 3–4% total sequence divergence from S. obesus populations on the nearby Baja California peninsula, and mainland populations of S. obesus obesus show similar levels of divergence from each other. An analysis of character transitions and comparative behavior implicates predation, and its relaxation on isolated islands, as a strong selective force in Sauromalus. Patterns of genetic differentiation in Sauromalus and biogeographic implications are discussed.     

Within and Between Species Variation in Male Mating Behaviors in the Mexican Sailfin Mollies Poecilia velifera and P. petenensis

Polymorphism in male morphology is often correlated with the expression of alternate behavioral tactics. This relationship between behavioral and morphological polymorphisms, however, is less well understood. We characterized male mating behaviors and morphological variation within and between Poecilia velifera and P. petenensis to understand mating signal evolution in the sailfin molly lineage. In addition, we examined whether differences between these species in the size range of mature males and the strength of allometry between dorsal fin size and body length could explain the variation observed in their expression of different mating behaviors. We determined each male's mating behavior profile by observing the behavior of a single male in the presence of a receptive female. We found that P. velifera showed evidence of an alternate male mating strategy, with small males generally performing only gonopodial thrusts (forced insemination attempts) towards receptive females, while large males performed courtship displays as well as gonopodial thrusts. Males of P. petenensis performed similar rates of courtship displays and gonopodial thrusts regardless of body length. Little variation existed among populations of P. velifera in mating behaviors, while males from different populations of P. petenensis showed population‐specific average rates of each mating behavior. Population differences in P. petenensis may be driven, in part, by its occurrence in more variable habitats than those occupied by P. velifera. Variation among individuals in the mating repertoire of P. velifera, but not P. petenensis, suggests that the greater range of variation in male size at maturity, as well as considerably stronger allometry between dorsal fin size and body length, may explain why males of P. velifera show the greatest degree of expression of alternate male mating behaviors when compared to other sailfin species. These results also suggest an important role of morphological polymorphisms in predicting the expression of alternate male mating behaviors.     

Quantitative analyses of cross-sectional shape of the distal radius in three species of macaques

I conducted quantitative analyses of the cross-sectional shape of the distal radial shaft in three species of macaques, which differ in locomotor behavior: semi-terrestrial Japanese macaques (Macaca fuscata), arboreal long tailed macaques (M. fascicularis), and relatively terrestrial rhesus macaques (M. mulatta). I took CT scans of the distal radial shafts of a total of 180 specimens at the level of the inferior radio-ulnar articulation. From each CT image, the periosteal outline of the radius was traced automatically by a digital imaging technique. I determined five points (landmarks) on the outline by developing a standardized morphometric technique. Bone surface lengths were measured by using these landmarks and their soft tissue correlates were investigated. The results of this study were as follows: (1) Semi-terrestrial M. fuscata has features that are approximately intermediate between those of the other two species. M. fuscata has a relatively small groove for M. abductor pollicis longus and a large groove for Mm. extensor carpi radialis longus et brevis. These characters resemble those of M. fascicularis. On the other hand, the ulnar notch of M. fuscata is relatively large, a character which is similar to that of M. mulatta. Moreover, compared to the other two macaques, the surface of the flexor muscles of M. fuscata is intermediate in size. (2) The more terrestrial M. mulatta has a relatively large groove for M. abductor pollicis longus and a small groove for Mm. extensor carpi radialis longus et brevis. Moreover, M. mulatta has a relatively large ulnar notch and a small surface for the flexor muscles. (3) The arboreal M. fascicularis has similar features to those of M. fuscata for the first and second relative size index. However, in the ulnar notch, M. fascicularis has a peculiar character and the surface for the flexor muscles is relatively large compared to those of the other two species. These results can be interpreted in terms of positional habits and presumed functional demands. A form-functional study by Lemelin and Schmitt also corroborates the interpretations of the present study. Thus, the distal region of the forearm strongly reflects muscular development and joint resultant force, and is an important region for investigating locomotor adaptations in primates. The present study reveals the possibility of using this type of morphometric analysis for reconstructing the positional behavior of fossil primates.     

Ancient genome‐wide admixture extends beyond the current hybrid zone between Macaca fascicularis and M. mulatta

Macaca fascicularis and Macaca mulatta are two of the most commonly used laboratory macaques, yet their genetic differences at a genome‐wide level remain unclear. We analysed the multilocus DNA sequence data of 54 autosomal loci obtained from M. fascicularis samples from three different geographic origins and M. mulatta samples of Burmese origin. M. fascicularis shows high nucleotide diversity, four to five times higher than humans, and a strong geographic population structure between Indonesian‐Malaysian and Philippine macaques. The pattern of divergence and polymorphism between M. fascicularis and M. mulatta shows a footprint of genetic exchange not only within their current hybrid zone but also across a wider range for more than 1 million years. However, genetic admixture may not be a random event in the genome. Whereas randomly selected genic and intergenic regions have the same evolutionary dynamics between the species, some cytochrome oxidase P450 (CYP) genes (major chemical metabolizing genes and potential target genes for local adaptation) have a significantly larger species divergence than other genes. By surveying CYP3A5 gene sequences of more than a hundred macaques, we identified three nonsynonymous single nucleotide polymorphisms that were highly differentiated between the macaques. The mosaic pattern of species divergence in the genomes may be a consequence of genetic differentiation under ecological adaptation and may be a salient feature in the genomes of nascent species under parapatry.     

Interpreting the Role of Climbing in Primate Locomotor Evolution: Are the Biomechanics of Climbing Influenced by Habitual Substrate Use and Anatomy?

Vertical climbing is widely accepted to have played an important role in the origins of both primate locomotion and of human bipedalism. Yet, only a few researchers have compared climbing mechanics in quadrupedal primates that vary in their degree of arboreality. It is assumed that primates using vertical climbing with a relatively high frequency will have morphological and behavioral specializations that facilitate efficient climbing mechanics. We test this assumption by examining whether time spent habitually engaged in climbing influences locomotor parameters such as footfall sequence, peak forces, and joint excursions during vertical climbing. Previous studies have shown that during climbing, the pronograde and semiterrestrial Macaca fuscata differs in these parameters compared to the more arboreal and highly specialized, antipronograde Ateles geoffroyi. Here, we examine whether a fully arboreal, quadrupedal primate that does not regularly arm-swing will exhibit gait and force distribution patterns intermediate between those of Macaca fuscata and Ateles geoffroyi. We collected footfall sequence, limb peak vertical forces, and 3D hindlimb excursion data for Macaca fascicularis during climbing on a stationary pole instrumented with a force transducer. Results show that footfall sequences are similar between macaque species, whereas peak force distributions and hindlimb excursions for Macaca fascicularis are intermediate between values reported for M. fuscata and Ateles geoffroyi. These results support the notion that time spent climbing is reflected in climbing mechanics, even though morphology may not provide for efficient mechanics, and highlight the important role of arboreal locomotor activity in determining the pathways of primate locomotor evolution.     

Evolution of skull and body shape in Triturus newts reconstructed from three‐dimensional morphometric data and phylogeny

To explore the relationship between morphological change and species diversification, we reconstructed the evolutionary changes in skull size, skull shape, and body elongation in a monophyletic group of eight species that make up salamander genus Triturus. Their well‐studied phylogenetic relationships and the marked difference in ecological preferences among five species groups makes this genus an excellent model system for the study of morphological evolution. The study involved three‐dimensional imagery of the skull and the number of trunk vertebrae, in material that represents the morphological, spatial, and molecular diversity of the genus. Morphological change largely followed the pattern of descent. The reconstruction of ancestral skull shape indicated that morphological change was mostly confined to two episodes, corresponding to the ancestral lineage that all crested newts have in common and the Triturus dobrogicus lineage. When corrected for common descent, evolution of skull shape was correlated to change in skull size. Also, skull size and shape, as well as body shape, as inferred from the number of trunk vertebrae, were correlated, indicating a marked impact of species' ecological preferences on morphological evolution, accompanied by a series of niche shifts, with the most pronounced one in the T. dobrogicus lineage. The presence of phylogenetic signal and correlated evolutionary changes in skull and body shape suggested complex interplay of niche shifts, natural selection, and constraints by a common developmental system. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 243–255.     

Mechanisms for Speciation inGalago andTarsius

Patterson's Recognition Concept of Species has profound implications for the way we analyze the process of species formation. It emphasizes absolute rather than relativistic mechanisms, and concentrates on adaptive processes within population isolates rather than competitive exclusion or competition. Environmental change is seen as a major force initiating speciation. In the case of two species ofGalago, environmental degradation and the breakup of forest blocks is likely to have been the major initiator; while changes in sea-level may have lead to the fragmentation of populations ofTarsius. In both cases, however, the relationships of body size, energetics, heterochrony and species strategies most likely provided the engine for further behavioural and morphological divergence.     

Morphological differentiation correlates with ecological but not with genetic divergence in a Gehyra gecko

Body size affects life history, the ecological niche of an organism and its interactions with other organisms. Resultantly, marked differences in body size between related organisms are often an indication of a species boundary. This is particularly evident in the Gehyra variegata species complex of geckos, which displays differential body sizes between genetically divergent species, but high levels of intraspecific morphological conservatism. We report on a Gehyra population that displays extraordinary body size differentiation in comparison with other G. variegata species. We used morphological and environmental data to show this population is phenotypically and ecologically distinct from its parapatric congener Gehyra lazelli and that morphology and ecology are significantly correlated. Contrastingly, mtDNA analysis indicates paraphyly between the two groups, and allele frequencies at six microsatellite loci show no population structure concordant with morpho‐/ecotype. These results suggest either ecological speciation or environmentally induced phenotypic polymorphism, in an otherwise morphologically conservative group.