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Results for “phenotypic divergence”

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PubMed2000

Divergent phenotypic patterns and commitment to apoptosis of Caco-2 cells during spontaneous and butyrate-induced differentiation.

Caco-2 cells differentiate spontaneously when cultured in confluence and on exposure to the physiologically relevant short-chain fatty acid, butyrate. This study aimed to compare the phenotype induced by these pathways and their relations to cell turnover. Caco-2 cells were treated with butyrate at a nontoxic concentration of 2 mM for 3 days, or allowed to spontaneously differentiate for 0-21 days. Brush border hydrolase activities and carcinoembryonic antigen (CEA) expression, transepithelial resistance and dome formation, expression of components of the urokinase system, and cell turnover by flow cytometry, and the degree of DNA fragmentation were quantified. Butyrate induced increases in alkaline phosphatase activity and CEA expression but not the activities of other hydrolases, while culture alone induced progressive increases in the activities/expression of all markers. Butyrate induced a significantly greater increase in transepithelial resistance (TER) than occurred during culture alone but the densities of domes were similar. Butyrate induced a ninefold increase in urokinase receptor expression and twofold increase in urokinase activity, while culture alone induced a significantly smaller increase in receptor expression, an increase in plasminogen activator inhibitor-1 but no change in activity. While both stimuli induced cell cycle arrest, only butyrate increased the proportion of cells undergoing apoptosis. In conclusion, differentiation of Caco-2 cells can proceed along multiple pathways but does not necessarily lead to apoptosis. The phenotypic changes during spontaneous differentiation mimic those that occur in normal colonic epithelial cells in vivo during their migration from the crypt base to neck, while butyrate-induced effects more closely follow those occurring when normal colonic epithelial cells migrate from crypt neck to the surface compartment.

Alkaline Phosphatase↗
PubMed2004

AL-amyloidosis and light-chain deposition disease light chains induce divergent phenotypic transformations of human mesangial cells.

Human mesangial cells (HMCs) are injured by either excessive amounts or abnormal light chains (LCs), or a combination of both in patients with plasma cell dyscrasias. Consequently, these HMCs undergo phenotypic transformations. HMCs were incubated with eight different light-chains (LCs) for 96 h. These cells, in addition to 51 patient samples from patients with AL-amyloidosis (AL-Am), light-chain deposition disease (LCDD), myeloma cast nephropathy (MCN) and controls were analyzed by immunohistochemistry for CD68, muscle-specific actin (MSA), smooth muscle actin (SMA), CD14, and Ham56 protein expressions. All samples were also studied using electron microscopy. Greater staining (four- and three-fold) expressions of CD68 and Ham56, respectively, were observed in the HMCs incubated with AL-Am-LCs compared to those with LCDD-LCs and control. SMA expression levels were five-fold higher in LCDD-LC-treated cells compared to the other categories of LC-treated and control cells. Similar results were obtained in the renal specimens, however, CD68 levels were 12-fold higher in the AL-Am cases compared to the LCDD cases, respectively. Conversely, MSA and SMA levels were three fold higher in the LCDD cases than in the AL-Am ones. No CD14 expression was noted in any of the samples and CD-34 staining of HMCs treated with the various LCs only showed rare positive cells. Dynamic real-time studies to visualize the rough endoplasmic reticulum (RER) and lysosomal compartments in HMCs incubated with LCDD and AL-Am-LCs showed striking expansion of each of the above-mentioned compartments, respectively. This indicates the presence of more RER in the LCDD-LC-treated HMCs and a striking increase in lysosomes noticeable in the AL-Am-LC-treated cells. Data obtained in this study highlighted that HMCs incubated with LCDD-LCs undergo a myofibroblastic phenotypic transformation, while AL-Am-LCs induce a macrophage-like phenotype in these cells.

Actins↗
PubMed2005

Divergent phenotypes in Gaucher disease implicate the role of modifiers.

BACKGROUND: Gaucher disease is classified into neuronopathic and non-neuronopathic forms with wide phenotypic variation among patients sharing the same genotype. While homozygosity for the common L444P allele usually correlates with the neuronopathic forms, how a defined genotype leads to a phenotype remains unknown. METHODS: The genetic and epigenetic factors causing phenotypic differences were approached by a clinical association study in 32 children homozygous for the point mutation L444P. Direct sequencing and Southern blots were utilised to establish the genotype and exclude recombinant alleles. Glucocerebrosidase activity was measured in lymphoblast and fibroblast cell lines. RESULTS: Residual enzyme activity was highly variable and did not correlate with the observed clinical course. There was also a wide spectrum of phenotypes. Average age at diagnosis was 15 months, and slowed saccadic eye movements were the most prevalent finding. The most severe systemic complications and highest mortality occurred in splenectomised patients before the advent of enzyme replacement therapy (ERT). On ERT, as morbidity and mortality decreased, developmental and language deficits emerged as a major issue. Some trends related to ethnic background were observed. CONCLUSION: The wide clinical spectrum observed in the L444P homozygotes implicates the contribution of genetic modifiers in defining the phenotype in Gaucher disease.

Child, Preschool↗
PubMed2002

Male fertility is compatible with an Arg(840)Cys substitution in the AR in a large Chinese family affected with divergent phenotypes of AR insensitivity syndrome.

Androgen insensitivity syndrome (AIS) is a disorder of male sexual development caused by an absent or dysfunctional AR. Fertile cases with mild AIS and slightly impaired AR activity had been reported in literature, and their external genitalia were documented to be usually normal or subnormal. We reported here an Arg(840)Cys substitution in the AR gene in a large Chinese pedigree affected with AIS. The mutant gene may result in infertility for some affected males with or without hypospadias. However, it was also observed that the mutation did not affect the fertility of the other patients. The gonadotropin levels for one of these patients were within the normal range. Thus, whether normal levels of the gonadotropins are necessary for the preserved fertility of patients affected with this genetic disorder remains to be elucidated.

Adolescent↗
PubMed2003

Parkin-proven disease: common founders but divergent phenotypes.

OBJECTIVE: To compare and contrast clinical and genetic findings in six probands with parkinsonism with a parkin exon 3 438- to 477-bp deletion (Ex3Delta40) to search for evidence of a common founder. METHOD: Clinical review, parkin gene sequencing, dosage studies, and high-resolution genotype/haplotype analysis were performed. RESULTS: All subjects had two or more signs consistent with a diagnosis of possible or probable PD with age at onset younger than 45 years (mean +/- SD 29.3 +/- 10.2 years, range 16 to 42 years). Affected individuals were either homozygotes, compound heterozygotes, or Ex3Delta40 carriers with one normal parkin allele. Haplotype analysis revealed both Ex3Delta40 and Ex7 924 C-->T (R275W) mutations originated from common founders, the former most probably of Irish descent. Although three cases had Ex7 924 C-->T (R275W) and Ex3Delta40 mutations, their clinical presentation and mode of inheritance were variable. CONCLUSION: Parkin mutations on common parkin haplotypes provide testable hypotheses of parkin function in genetically defined parkinsonism.

Adult↗
PubMed2004

Allelic diversification at the C (OsC1) locus of wild and cultivated rice: nucleotide changes associated with phenotypes.

Divergent phenotypes are often detected in domesticated plants despite the existence of invariant phenotypes in their wild forms. One such example in rice is the occurrence of varying degrees of apiculus coloration due to anthocyanin pigmentation, which was previously reported to be caused by a series of alleles at the C locus. The present study reveals, on the basis of comparison of its maps, that the C gene appears to be the rice homolog (OsC1) of maize C1, which belongs to the group of R2R3-Myb factors. Two different types of deletions causing a frameshift were detected in the third exon, and both of the deleted nucleotides corresponded to the positions of putative base-contacting residues, suggesting that the Indica and Japonica types carry loss-of-function mutations with independent origins. In addition, replacement substitutions were frequently detected in OsC1 of strains carrying the previously defined C alleles. Molecular population analysis revealed that 17 haplotypes were found in 39 wild and cultivated rices, and the haplotypes of most cultivated forms could be classified into one of three distinct groups, with few shared haplotypes among taxa, including Indica and Japonica types. The genealogy of the OsC1 gene suggests that allelic diversification causing phenotypic change might have resulted from mutations in the coding region rather than from recombination between preexisting alleles. The McDonald and Kreitman test revealed that the changes in amino acids might be associated with selective forces acting on the lineage of group A whose haplotypes were carried by most Asian cultivated forms. The results regarding a significant implication for genetic diversity in landraces of rice are also discussed.

Alleles↗
PubMed2003

The constancy of the G matrix through species divergence and the effects of quantitative genetic constraints on phenotypic evolution: a case study in crickets.

Long-term phenotypic evolution can be modeled using the response-to-selection equation of quantitative genetics, which incorporates information about genetic constraints (the G matrix). However, little is known about the evolution of G and about its long-term importance in constraining phenotypic evolution. We first investigated the degree of conservation of the G matrix across three species of crickets and qualitatively compared the pattern of variation of G to the phylogeny of the group. Second, we investigated the effect of G on phenotypic evolution by comparing the direction of greatest quantitative genetic variation within species (g(max)) to the direction of phenotypic divergence between species (Delta(z)). Each species, Gryllus veletis, G. firmus, and G. pennsylvanicus, was reared in the laboratory using a full-sib breeding design to extract quantitative genetic information. Five morphological traits related to size were measured. G matrices were compared using three statistical approaches: the T method, the Flury hierarchy, and the MANOVA method. Results revealed that the differences between matrices were small and mostly caused by differences in the magnitude of the genetic variation, not by differences in principal component structure. This suggested that the G matrix structure of this group of species was preserved, despite significant phenotypic divergence across species. The small observed differences in G matrices across species were qualitatively consistent with genetic distances, whereas ecological information did not provide a good prediction of G matrix variation. The comparison of g(max) and Delta(z) revealed that the angle between these two vectors was small in two of three species comparisons, whereas the larger angle corresponding to the third species comparison was caused in large part by one of the five traits. This suggests that multivariate phenotypic divergence occurred mostly in a direction predicted by the direction of greatest genetic variation, although it was not possible to demonstrate the causal relationship from G to Delta(z). Overall, this study provided some support for the validity of the predictive power of quantitative genetics over evolutionary time scales.

Analysis of Variance↗
PubMed2005

Comparative landscape genetics and the adaptive radiation of Darwin's finches: the role of peripheral isolation.

We use genetic divergence at 16 microsatellite loci to investigate how geographical features of the Galápagos landscape structure island populations of Darwin's finches. We compare the three most genetically divergent groups of Darwin's finches comprising morphologically and ecologically similar allopatric populations: the cactus finches (Geospiza scandens and Geospiza conirostris), the sharp-beaked ground finches (Geospiza difficilis) and the warbler finches (Certhidea olivacea and Certhidea fusca). Evidence of reduced genetic diversity due to drift was limited to warbler finches on small, peripheral islands. Evidence of low levels of recent interisland migration was widespread throughout all three groups. The hypothesis of distance-limited dispersal received the strongest support in cactus and sharp-beaked ground finches as evidenced by patterns of isolation by distance, while warbler finches showed a weaker relationship. Support for the hypothesis that gene flow constrains morphological divergence was only found in one of eight comparisons within these groups. Among warbler finches, genetic divergence was relatively high while phenotypic divergence was low, implicating stabilizing selection rather than constraint due to gene flow. We conclude that the adaptive radiation of Darwin's finches has occurred in the presence of ongoing but low levels of gene flow caused by distance-dependent interisland dispersal. Gene flow does not constrain phenotypic divergence, but may augment genetic variation and facilitate evolution due to natural selection. Both microsatellites and mtDNA agree in that subsets of peripheral populations of two older groups are genetically more similar to other species that underwent dramatic morphological change. The apparent decoupling of morphological and molecular evolution may be accounted for by a modification of Lack's two-stage model of speciation: relative ecological stasis in allopatry followed by secondary contact, ecological interactions and asymmetric phenotypic divergence.

Adaptation, Biological↗
PubMed2005

Adreno-leukodystrophy: oxidative stress of mice and men.

X-linked adreno-leukodystrophy is a progressive, systemic peroxisomal disorder that affects primarily nervous system myelin and axons as well as the adrenal cortex. Several divergent clinical phenotypes can occur in the same family; thus, there is no correlation between the clinical phenotype and the mutation in the ABCD1 gene in this disease. The most urgent and unresolved clinical issue is the fulminant inflammatory (immune) demyelination of the central nervous system in which a variety of cellular participants, cytokines, and chemokines are noted. A knockout mouse model exhibits mitochondrial deficits and axonal degeneration, but not inflammatory demyelination. To determine whether oxidative stress and damage might play a pathogenic role, we assessed standard biochemical and immunohistochemical markers of such activity both in our knockout mouse model and patients. We find that oxidative stress, as judged by increased immunoreactivity for the mitochondrial manganese-superoxide dismutase, is present in the knockout mouse liver, adrenal cortex, and renal cortex, tissues that normally express high levels of ABCD1 but no evidence of oxidative damage. The brain does not exhibit either oxidative stress or damage. On the other hand, both the human adrenal cortex and brain show evidence of oxidative stress (e.g. hemoxygenase-1 and manganese-superoxide dismutase) and oxidative damage, particularly from lipid peroxidation (4-hydroxynonenal and malondialdehyde). The presence of nitrotyrosylated proteins is strong circumstantial evidence for the participation of the highly toxic peroxynitrite molecule, whereas the demonstration of interferon gamma and interleukin-12 is indicative of a TH1 response in the inflammatory demyelinative lesions of the cerebral phenotype. These differences between the adreno-leukodystrophy mouse and human patients are intriguing and may provide a clue to the phenotypic divergence in this disease.

Adrenal Cortex↗
PubMed2002

Divergence and reproductive isolation in the early stages of speciation.

To understand speciation we need to identify the factors causing divergence between natural populations. The traditional approach to gaining such insights has been to focus on a particular theory and ask whether observed patterns of reproductive isolation between populations or species are consistent with the hypothesis in question. However, such studies are few and they do not allow us to compare between hypotheses, so often we cannot determine the relative contribution to divergence of different potential factors. Here, I describe a study of patterns of phenotypic divergence and premating and postmating isolation between populations of the grasshopper Chorthippus parallelus. Information on the phylogeographic relationships of the populations means that a priori predictions from existing hypotheses for the evolution of reproductive isolation can be compared with observations. I assess the relative contributions to premating isolation, postmating isolation and phenotypic divergence of long periods of allopatry, adaptation to different environments and processes associated with colonisation (such as population bottlenecks). Likelihood analysis reveals that long periods of allopatry in glacial refugia are associated with postmating reproductive isolation, but not premating isolation, which is more strongly associated with colonisation. Neither premating nor postmating isolation is higher between populations differing in potential environmental selection pressures. There are only weak correlations between patterns of genetic divergence and phenotypic divergence and no correlation between premating and postmating isolation. This suggests that the potential of a taxon to exercise mate choice may affect the types of factor that promote speciation in that group. I discuss the advantages and disadvantages of the general approach of simultaneously testing competing hypotheses for the evolution of reproductive isolation.

Acoustic Stimulation↗
PubMed2025

Complex and Dynamic Gene-by-Age and Gene-by-Environment Interactions Underlie Functional Morphological Variation in Adaptive Divergence in Arctic Charr (Salvelinus alpinus).

The evolution of adaptive phenotypic divergence requires heritable genetic variation. However, it is underappreciated that trait heritability is molded by developmental processes interacting with the environment. We hypothesized that the genetic architecture of divergent functional traits was dependent on age and foraging environment. Thus, we induced plasticity in full-sib families of Arctic charr (Salvelinus alpinus) morphs from two Icelandic lakes by mimicking prey variation in the wild. We characterized variation in body shape and size at two ages and investigated their genetic architecture with quantitative trait locus (QTL) analysis. Age had a greater effect on body shape than diet in most families, suggesting that development strongly influences phenotypic variation available for selection. Consistent with our hypothesis, multiple QTL were detected for all traits and their location depended on age and diet. Many of the genome-wide QTL were located within a subset of duplicated chromosomal regions suggesting that ancestral whole genome duplication events have played a role in the genetic control of functional morphological variation in the species. Moreover, the detection of two body shape QTL after controlling for the effects of age provides additional evidence for genetic variation in the plastic response of morphological traits to environmental variation. Thus, functional morphological traits involved in phenotypic divergence are molded by complex genetic interactions with development and environment.

Animals↗
PubMed2002

Changes in connexin43 in early ocular surface development.

PURPOSE: In the limbo-corneal epithelium the stem and early precursor epithelial cell pool is confined to the limbal rim. Among the features associated with this spatial segregation is the general paucity of connexin43 (Cx43) within the limbal basal cell population and its complete absence in resident stem cells. The limbo-corneal epithelial lineage derives from a Cx43-positive (Cx43+) embryonic outer ectoderm. Accordingly, as a means of identifying the process through which limbal cell phenotypes emerge, we investigated the expression of Cx43 in the ocular surface of embryonic rats. METHODS: Ocular surface expression of Cx43 or K12 was determined in cryostat sections of rat embryos and eyes using immunohistological methods. RESULTS: Changes in Cx43 expression revealed the early phenotypic divergence of three main epithelial cell phenotypes of the ocular surface. An analysis of the level and distribution pattern of Cx43 puncta lead to the identification of two distinct domains by embryonic day 10 (E10), a stage that occurs soon after formation of the lens vesicle. Additionally, at E12, ectodermal cells directly adjacent to the edges of the developing retina no longer express connexin. A comparison of anatomical and expression changes throughout embryonic development demonstrated that the two early zones represent the rudiments for the epithelia of the central cornea and conjunctiva, respectively, and that the isolated Cx43-negative (Cx43-) cells represent the precursors of the basal and, putatively, stem cells of the limbal epithelium. CONCLUSIONS: Changes in Cx43 expression revealed that the phenotypic divergence of ocular surface epithelial cells and the generation of limbo-corneal stem cell precursors takes place at a very early stage in ocular development, ahead of the establishment of any identifiable anatomical or differentiation features for these domains.

Animals↗
PubMed2003

Immunophenotype of desmoplastic small round cell tumors as detected in cases with EWS-WT1 gene fusion product.

Desmoplastic small round cell tumor is a rare tumor typically involving peritoneum. Although the histogenesis of desmoplastic small round cell tumor has yet to be elucidated, immunophenotypical and morphological analysis shows a characteristic divergent phenotype overlapping with other round cell tumors such as Ewing's sarcoma/primitive neuroectodermal tumor, rhabdomyosarcoma, small cell mesothelioma, and carcinoma. Detection of the EWS-WT1 gene fusion is characteristic of desmoplastic small round cell tumor and has been used reliably in tumor diagnosis. In this study, we evaluated the immunophenotype of 23 desmoplastic small round cell tumor cases with the EWS-WT1 gene fusion product identified by reverse transcription-polymerase chain reaction. Paraffin sections were stained with antibodies against calretinin, WT1 (C19), desmin, myoglobin, MyoD, Myf5, myogenin, placental alkaline phosphatase, cytokeratins, MIC2, HER2/neu and c-kit using standard immunohistochemical methods. Immunoreactivity was evaluated semiquantitively by light microscopy. Desmoplastic small round cell tumors showed reactivity with calretinin in 4/21, desmin in 21/23, myoglobin in 5/17, placental alkaline phosphatase in 17/21, HER2/neu in 7/18 (3+ in 1 and 1+ in 6), c-kit in 2/14, MIC2 in 13/23, WT1 in 16/23, CAM5.2 in 21/23, and AE1/3 in 16/23 cases. The most sensitive myogenic and epithelial markers are desmin and CAM 5.2. Although nuclear reactivity of the early myogenic regulatory factors (MyoD, myogenin, Myf5) was not detected, myoglobin immunoreactivity was present in 29% of desmoplastic small round cell tumors. HER2/neu overexpression (3+) and c-kit expression are uncommon in desmoplastic small round cell tumors. A panel of myogenic and epithelial markers should be used to detect the divergent phenotype in desmoplastic small round cell tumors, a key feature in the differential diagnosis. Detection of EWS-WT1 fusion becomes critical for the diagnosis when the characteristic divergent phenotype cannot be detected immunohistochemically.

Antigens, Neoplasm↗
PubMed2005

Interaction of rearing environment and reproductive tactic on gene expression profiles in Atlantic salmon.

Organisms that share the same genotype can develop into divergent phenotypes, depending on environmental conditions. In Atlantic salmon, young males of the same age can be found either as sneakers or immature males that are future anadromous fish. Just as the organism-level phenotype varies between divergent male developmental trajectories, brain gene expression is expected to vary as well. We hypothesized that rearing environment can also have an important effect on gene expression in the brain and possibly interact with the reproductive tactic adopted. We tested this hypothesis by comparing brain gene expression profiles of the two male tactics in fish from the same population that were reared in either a natural stream or under laboratory conditions. We found that expression of certain genes was affected by rearing environment only, while others varied between male reproductive tactics independent of rearing environment. Finally, more than half of all genes that showed variable expression varied between the two male tactics only in one environment. Thus, in these fish, very different molecular pathways can give rise to similar macro-phenotypes depending on rearing environment. This result gives important insights into the molecular underpinnings of developmental plasticity in relationship to the environment.

Animals↗
PubMed2006

Phenotypic diversification and adaptation of Serratia marcescens MG1 biofilm-derived morphotypes.

We report here the characterization of dispersal variants from microcolony-type biofilms of Serratia marcescens MG1. Biofilm formation proceeds through a reproducible process of attachment, aggregation, microcolony development, hollow colony formation, and dispersal. From the time when hollow colonies were observed in flow cell biofilms after 3 to 4 days, at least six different morphological colony variants were consistently isolated from the biofilm effluent. The timing and pattern of variant formation were found to follow a predictable sequence, where some variants, such as a smooth variant with a sticky colony texture (SSV), could be consistently isolated at the time when mature hollow colonies were observed, whereas a variant that produced copious amounts of capsular polysaccharide (SUMV) was always isolated at late stages of biofilm development and coincided with cell death and biofilm dispersal or sloughing. The morphological variants differed extensively from the wild type in attachment, biofilm formation, and cell ultrastructure properties. For example, SSV formed two- to threefold more biofilm biomass than the wild type in batch biofilm assays, despite having a similar growth rate and attachment capacity. Interestingly, the SUMV, and no other variants, was readily isolated from an established SSV biofilm, indicating that the SUMV is a second-generation genetic variant derived from SSV. Planktonic cultures showed significantly lower frequencies of variant formation than the biofilms (5.05 x 10(-8) versus 4.83 x 10(-6), respectively), suggesting that there is strong, diversifying selection occurring within biofilms and that biofilm dispersal involves phenotypic radiation with divergent phenotypes.

Adaptation, Physiological↗
PubMed2006

What makes us human: revisiting an age-old question in the genomic era.

In 1970, Karl Pribram took on the immense challenge of asking the question, what makes us human? Nearly four decades later, the most significant finding has been the undeniable realization of how incredibly subtle and fine-scaled the unique biological features of our species must be. The recent explosion in the availability of large-scale sequence data, however, and the consequent emergence of comparative genomics, are rapidly transforming the study of human evolution. The field of comparative genomics is allowing us to reach unparalleled resolution, reframing our questions in reference to DNA sequence--the very unit that evolution operates on. But like any reductionist approach, it comes at a price. Comparative genomics may provide the necessary resolution for identifying rare DNA sequence differences in a vast sea of conservation, but ultimately we will have to face the challenge of figuring out how DNA sequence divergence translates into phenotypic divergence. Our goal here is to provide a brief outline of the major findings made in the study of human brain evolution since the Pribram lecture, focusing specifically on the field of comparative genomics. We then discuss the broader implications of these findings and the future challenges that are in store.

Journal Article↗
PubMed2001

Adaptive life-history evolution in the livebearing fish Brachyrhaphis rhabdophora: genetic basis for parallel divergence in age and size at maturity and a test of predator-induced plasticity.

I document a genetic basis for parallel evolution of life-history phenotypes in the livebearing fish Brachyrhaphis rhabdophora from northwestern Costa Rica. In previous work, I showed that populations of B. rhabdophora that co-occur with predators attain maturity at smaller sizes than populations that live in predator-free environments. I also demonstrated that this pattern of phenotypic divergence in life histories was independently repeated in at least five isolated drainages. However, life-history phenotypes measured from wild-caught fish could be attributed to environmental effects rather than to genetic differences among populations. In the present study, I reared male fish from four populations (two that co-occur with predators and two from predator-free environments) under four sets of environmental conditions. The pattern of phenotypic divergence in maturation size documented in the field between populations collected from different predation environments persisted after two generations in the laboratory. I also found a genetic basis for differences between populations in the age at which males attain maturity and in growth rates. By rearing fish in four different common environments, I tested for phenotypic plasticity in male life-history traits in response to nonlethal exposure to predators. There was a significant delay in the onset of sexual maturity in fish exposed to predators relative to those in the control, but no differences among treatments in size at maturity or growth rates. These results, coupled with previous work on B. rhabdophora, demonstrate a repeated pattern of parallel evolutionary divergence among genetically isolated populations that is strongly associated with predation.

Adaptation, Physiological↗