Displaying publications 1 - 20 of 110 in total

  1. Das S
    Anat Sci Int, 2008 Jun;83(2):120; author reply 121.
    PMID: 18507622 DOI: 10.1111/j.1447-073X.2008.00232.x
    Matched MeSH terms: Biological Evolution*
  2. Schwallier R, Gravendeel B, de Boer H, Nylinder S, van Heuven BJ, Sieder A, et al.
    Ann. Bot., 2017 05 01;119(7):1179-1193.
    PMID: 28387789 DOI: 10.1093/aob/mcx010
    Background and Aims: Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant's iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation.

    Methods: Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology.

    Key Results: Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales.

    Conclusions: The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre-sclereids that mainly occur idioblastically in pith and cortex are synapomorphic for Nepenthes , while other typical Nepenthes characters evolved convergently in different Caryophyllales lineages.

    Matched MeSH terms: Biological Evolution*
  3. Polgar G, Malavasi S, Cipolato G, Georgalas V, Clack JA, Torricelli P
    PLoS ONE, 2011;6(6):e21434.
    PMID: 21738663 DOI: 10.1371/journal.pone.0021434
    Coupled behavioural observations and acoustical recordings of aggressive dyadic contests showed that the mudskipper Periophthalmodon septemradiatus communicates acoustically while out of water. An analysis of intraspecific variability showed that specific acoustic components may act as tags for individual recognition, further supporting the sounds' communicative value. A correlative analysis amongst acoustical properties and video-acoustical recordings in slow-motion supported first hypotheses on the emission mechanism. Acoustic transmission through the wet exposed substrate was also discussed. These observations were used to support an "exaptation hypothesis", i.e. the maintenance of key adaptations during the first stages of water-to-land vertebrate eco-evolutionary transitions (based on eco-evolutionary and palaeontological considerations), through a comparative bioacoustic analysis of aquatic and semiterrestrial gobiid taxa. In fact, a remarkable similarity was found between mudskipper vocalisations and those emitted by gobioids and other soniferous benthonic fishes.
    Matched MeSH terms: Biological Evolution*
  4. Teo J, Abbass HA
    Evol Comput, 2004;12(3):355-94.
    PMID: 15355605
    In this paper, we investigate the use of a self-adaptive Pareto evolutionary multi-objective optimization (EMO) approach for evolving the controllers of virtual embodied organisms. The objective of this paper is to demonstrate the trade-off between quality of solutions and computational cost. We show empirically that evolving controllers using the proposed algorithm incurs significantly less computational cost when compared to a self-adaptive weighted sum EMO algorithm, a self-adaptive single-objective evolutionary algorithm (EA) and a hand-tuned Pareto EMO algorithm. The main contribution of the self-adaptive Pareto EMO approach is its ability to produce sufficiently good controllers with different locomotion capabilities in a single run, thereby reducing the evolutionary computational cost and allowing the designer to explore the space of good solutions simultaneously. Our results also show that self-adaptation was found to be highly beneficial in reducing redundancy when compared against the other algorithms. Moreover, it was also shown that genetic diversity was being maintained naturally by virtue of the system's inherent multi-objectivity.
    Matched MeSH terms: Biological Evolution*
  5. Klomp DA, Ord TJ, Das I, Diesmos A, Ahmad N, Stuart-Fox D
    J. Evol. Biol., 2016 Sep;29(9):1689-700.
    PMID: 27234454 DOI: 10.1111/jeb.12908
    Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity.
    Matched MeSH terms: Biological Evolution*
  6. Norhazrina N, Vanderpoorten A, Hedenäs L, Patiño J
    Mol. Phylogenet. Evol., 2016 12;105:139-145.
    PMID: 27530707 DOI: 10.1016/j.ympev.2016.08.008
    As opposed to angiosperms, moss species richness is similar among tropical regions of the world, in line with the hypothesis that tropical bryophytes are extremely good dispersers. Here, we reconstructed the phylogeny of the pantropical moss genus Pelekium to test the hypothesis that high migration rates erase any difference in species richness among tropical regions. In contrast with this hypothesis, several species considered to have a pantropical range were resolved as a complex of species with a strong geographic structure. Consequently, a significant phylogeographical signal was found in the data, evidencing that cladogenetic diversification within regions takes place at a faster rate than intercontinental migration. The shape of the Pelekium phylogeny, along with the selection of a constant-rate model of diversification among species in the genus, suggests, however, that the cladogenetic speciation patterns observed in Pelekium are not comparable to some of the spectacular examples of tropical radiations reported in angiosperms. Rather, the results presented here point to the constant accumulation of diversity through time in Pelekium. This, combined with evidence for long-distance dispersal limitations in the genus, suggests that the similar patterns of species richness among tropical areas are better explained in terms of comparable rates of diversification across tropical regions than by the homogenization of species richness by recurrent migrations.
    Matched MeSH terms: Biological Evolution*
  7. van Wyhe J
    PMID: 27721035 DOI: 10.1016/j.shpsc.2016.09.004
    This article examines six main elements in the modern story of the impact of Alfred Russel Wallace's 1855 Sarawak Law paper, particularly in the many accounts of Charles Darwin's life and work. These elements are: Each of these are very frequently repeated as straightforward facts in the popular and scholarly literature. It is here argued that each of these is erroneous and that the role of the Sarawak Law paper in the historiography of Darwin and Wallace needs to be revised.
    Matched MeSH terms: Biological Evolution*
  8. Wang MMH, Gardner EM, Chung RCK, Chew MY, Milan AR, Pereira JT, et al.
    Am. J. Bot., 2018 05;105(5):898-914.
    PMID: 29874392 DOI: 10.1002/ajb2.1094
    PREMISE OF THE STUDY: Underutilized crops and their wild relatives are important resources for crop improvement and food security. Cempedak [Artocarpus integer (Thunb). Merr.] is a significant crop in Malaysia but underutilized elsewhere. Here we performed molecular characterization of cempedak and its putative wild relative bangkong (Artocarpus integer (Thunb). Merr. var. silvestris Corner) to address questions regarding the origin and diversity of cempedak.

    METHODS: Using data from 12 microsatellite loci, we assessed the genetic diversity and genetic/geographic structure for 353 cempedak and 175 bangkong accessions from Malaysia and neighboring countries and employed clonal analysis to characterize cempedak cultivars. We conducted haplotype network analyses on the trnH-psbA region in a subset of these samples. We also analyzed key vegetative characters that reportedly differentiate cempedak and bangkong.

    KEY RESULTS: We show that cempedak and bangkong are sister taxa and distinct genetically and morphologically, but the directionality of domestication origin is unclear. Genetic diversity was generally higher in bangkong than in cempedak. We found a distinct genetic cluster for cempedak from Borneo as compared to cempedak from Peninsular Malaysia. Finally, cempedak cultivars with the same names did not always share the same genetic fingerprint.

    CONCLUSIONS: Cempedak origins are complex, with likely admixture and hybridization with bangkong, warranting further investigation. We provide a baseline of genetic diversity of cempedak and bangkong in Malaysia and found that germplasm collections in Malaysia represent diverse coverage of the four cempedak genetic clusters detected.

    Matched MeSH terms: Biological Evolution*
  9. Ruzanna Zam Zam
    ASEAN Journal of Psychiatry, 2010;11(1):113-0.
    This paper discusses the evolution of PSR development for people with severe mental illness since the early 20th century in Malaysia. The various aspects of PSR include the activities, service target, the treatment settings, factors contributed to the development and the challenges that have been faced are also described along with the evolution, comparing the past and
    present. It is learned that despite of many challenges, PSR in Malaysia has now continued to progress with increasing supports from the stakeholders and is in keeping with the current PSR concept.
    Matched MeSH terms: Biological Evolution
  10. Xu X, Liu F, Cheng RC, Chen J, Xu X, Zhang Z, et al.
    Proc. Biol. Sci., 2015 Jun 07;282(1808):20142486.
    PMID: 25948684 DOI: 10.1098/rspb.2014.2486
    Living fossils are lineages that have retained plesiomorphic traits through long time periods. It is expected that such lineages have both originated and diversified long ago. Such expectations have recently been challenged in some textbook examples of living fossils, notably in extant cycads and coelacanths. Using a phylogenetic approach, we tested the patterns of the origin and diversification of liphistiid spiders, a clade of spiders considered to be living fossils due to their retention of arachnid plesiomorphies and their exclusive grouping in Mesothelae, an ancient clade sister to all modern spiders. Facilitated by original sampling throughout their Asian range, we here provide the phylogenetic framework necessary for reconstructing liphistiid biogeographic history. All phylogenetic analyses support the monophyly of Liphistiidae and of eight genera. As the fossil evidence supports a Carboniferous Euramerican origin of Mesothelae, our dating analyses postulate a long eastward over-land dispersal towards the Asian origin of Liphistiidae during the Palaeogene (39-58 Ma). Contrary to expectations, diversification within extant liphistiid genera is relatively recent, in the Neogene and Late Palaeogene (4-24 Ma). While no over-water dispersal events are needed to explain their evolutionary history, the history of liphistiid spiders has the potential to play prominently in vicariant biogeographic studies.
    Matched MeSH terms: Biological Evolution*
  11. Fiala I, Hlavničková M, Kodádková A, Freeman MA, Bartošová-Sojková P, Atkinson SD
    Mol. Phylogenet. Evol., 2015 May;86:75-89.
    PMID: 25797924 DOI: 10.1016/j.ympev.2015.03.004
    In order to clarify the phylogenetic relationships among the main marine myxosporean clades including newly established Ceratonova clade and scrutinizing their evolutionary origins, we performed large-scale phylogenetic analysis of all myxosporean species from the marine myxosporean lineage based on three gene analyses and statistical topology tests. Furthermore, we obtained new molecular data for Ceratonova shasta, C. gasterostea, eight Ceratomyxa species and one Myxodavisia species. We described five new species: Ceratomyxa ayami n. sp., C. leatherjacketi n. sp., C. synaphobranchi n. sp., C. verudaensis n. sp. and Myxodavisia bulani n. sp.; two of these formed a new, basal Ceratomyxa subclade. We identified that the Ceratomyxa clade is basal to all other marine myxosporean lineages, and Kudoa with Enteromyxum are the most recently branching clades. Topologies were least stable at the nodes connecting the marine urinary clade, the marine gall bladder clade and the Ceratonova clade. Bayesian inference analysis of SSU rDNA and the statistical tree topology tests suggested that Ceratonova is closely related to the Enteromyxum and Kudoa clades, which represent a large group of histozoic species. A close relationship between Ceratomyxa and Ceratonova was not supported, despite their similar myxospore morphologies. Overall, the site of sporulation in the vertebrate host is a more accurate predictor of phylogenetic relationships than the morphology of the myxospore.
    Matched MeSH terms: Biological Evolution*
  12. Hockings KJ, McLennan MR, Carvalho S, Ancrenaz M, Bobe R, Byrne RW, et al.
    Trends Ecol. Evol. (Amst.), 2015 Apr;30(4):215-22.
    PMID: 25766059 DOI: 10.1016/j.tree.2015.02.002
    We are in a new epoch, the Anthropocene, and research into our closest living relatives, the great apes, must keep pace with the rate that our species is driving change. While a goal of many studies is to understand how great apes behave in natural contexts, the impact of human activities must increasingly be taken into account. This is both a challenge and an opportunity, which can importantly inform research in three diverse fields: cognition, human evolution, and conservation. No long-term great ape research site is wholly unaffected by human influence, but research at those that are especially affected by human activity is particularly important for ensuring that our great ape kin survive the Anthropocene.
    Matched MeSH terms: Biological Evolution*
  13. Costa JT
    Theory Biosci., 2013 Dec;132(4):225-37.
    PMID: 24014172 DOI: 10.1007/s12064-013-0188-1
    Alfred Russel Wallace (1823-1913) and Charles Darwin (1809-1882) are honored as the founders of modern evolutionary biology. Accordingly, much attention has focused on their relationship, from their independent development of the principle of natural selection to the receipt by Darwin of Wallace's essay from Ternate in the spring of 1858, and the subsequent reading of the Wallace and Darwin papers at the Linnean Society on 1 July 1858. In the events of 1858 Wallace and Darwin are typically seen as central players, with Darwin's friends Charles Lyell (1797-1875) and Joseph Dalton Hooker (1817-1911) playing supporting roles. This narrative has resulted in an under-appreciation of a more central role for Charles Lyell as both Wallace's inspiration and foil. The extensive anti-transmutation arguments in Lyell's landmark Principles of Geology were taken as the definitive statement on the subject. Wallace, in his quest to solve the mystery of species origins, engaged with Lyell's arguments in his private field notebooks in a way that is concordant with his engagement with Lyell in the 1855 and 1858 papers. I show that Lyell was the object of Wallace's Sarawak Law and Ternate papers through a consideration of the circumstances that led Wallace to send his Ternate paper to Darwin, together with an analysis of the material that Wallace drew upon from the Principles. In this view Darwin was, ironically, intended for a supporting role in mediating Wallace's attempted dialog with Lyell.
    Matched MeSH terms: Biological Evolution*
  14. Kutschera U, Hossfeld U
    Theory Biosci., 2013 Dec;132(4):207-14.
    PMID: 23982797 DOI: 10.1007/s12064-013-0187-2
    The British naturalist Alfred Russel Wallace (1823-1913), who had to leave school aged 14 and never attended university, did extensive fieldwork, first in the Amazon River basin (1848-1852) and then in Southeast Asia (1854-1862). Based on this experience, and after reading the corresponding scientific literature, Wallace postulated that species were not created, but are modified descendants of pre-existing varieties (Sarawak Law paper, 1855). Evolution is brought about by a struggle for existence via natural selection, which results in the adaptation of those individuals in variable populations who survive and reproduce (Ternate essay, 1858). In his monograph Darwinism (1889), and in subsequent publications, Wallace extended the contents of Darwin's Origin of Species (1859) into the Neo-Darwinian theory of biological evolution, with reference to the work of August Weismann (1834-1914). Wallace also became the (co)-founder of biogeography, biodiversity research, astrobiology and evolutionary anthropology. Moreover, he envisioned what was later called the anthropocene (i.e., the age of human environmental destructiveness). However, since Wallace believed in atheistic spiritualism and mixed up scientific facts and supernatural speculations in some of his writings, he remains a controversial figure in the history of biology.
    Matched MeSH terms: Biological Evolution*
  15. Golding RE
    Mol. Phylogenet. Evol., 2012 Apr;63(1):72-81.
    PMID: 22210412 DOI: 10.1016/j.ympev.2011.12.016
    Amphiboloidea is a small but widespread group of snails found exclusively, and often abundantly, in mudflat and associated salt marsh or mangrove habitat. This study uses molecular data from three loci (COI, 16S and 28S) to infer phylogenetic relationships in Amphiboloidea and examine its position in Euthyneura. All but two of the named extant species of Amphiboloidea and additional undescribed taxa from across Southeast Asia and the Arabian Gulf were sampled. In contrast to the current morphology-based classification dividing Amphiboloidea into three families, analysis of molecular data supports revision of the classification to comprise two families. Maningrididae is a monotypic family basal to Amphibolidae, which is revised to comprise three subfamilies: Amphibolinae, Phallomedusinae and Salinatorinae. Sequence divergence between Asian populations of Naranjia is relatively large and possibly indicative of species complexes divergent across the Strait of Malacca. Salinatorrosacea and Salinator burmana do not cluster with other Salinator species, and require generic reassignment. In addition, sequences were obtained from an undescribed species of Lactiforis from the Malay Peninsula. Reconstruction of ancestral distributions indicates a plesiomorphic distribution and centre of origin in Australasia, with two genera subsequently diversifying throughout Asia. Increasing the sampling density of amphiboloid taxa in a phylogenetic analysis of Euthyneura did not resolve the identity of the sister taxon to Amphibolidae, but confirmed its inclusion in Pulmonata/Panpulmonata.
    Matched MeSH terms: Biological Evolution*
  16. Bagchi R, Press MC, Scholes JD
    Ecol. Lett., 2010 Jan;13(1):51-9.
    PMID: 19849708 DOI: 10.1111/j.1461-0248.2009.01397.x
    One important hypothesis to explain tree-species coexistence in tropical forests suggests that increased attack by natural enemies near conspecific trees gives locally rare species a competitive advantage. Host ranges of natural enemies generally encompass several closely related plant taxa suggesting that seedlings should also do poorly around adults of closely related species. We investigated the effects of adult Parashorea malaanonan on seedling survival in a Bornean rain forest. Survival of P. malaanonan seedlings was highest at intermediate distances from parent trees while heterospecific seedlings were unaffected by distance. Leaf herbivores did not drive this relationship. Survival of seedlings was lowest for P. malaanonan, and increased with phylogenetic dissimilarity from this species, suggesting that survival of close relatives of common species is reduced. This study suggests that distance dependence contributes to species coexistence and highlights the need for further investigation into the role of shared plant enemies in community dynamics.
    Matched MeSH terms: Biological Evolution*
  17. Clements R, Liew TS, Vermeulen JJ, Schilthuizen M
    Biol. Lett., 2008 Apr 23;4(2):179-82.
    PMID: 18182365 DOI: 10.1098/rsbl.2007.0602
    The manner in which a gastropod shell coils has long intrigued laypersons and scientists alike. In evolutionary biology, gastropod shells are among the best-studied palaeontological and neontological objects. A gastropod shell generally exhibits logarithmic spiral growth, right-handedness and coils tightly around a single axis. Atypical shell-coiling patterns (e.g. sinistroid growth, uncoiled whorls and multiple coiling axes), however, continue to be uncovered in nature. Here, we report another coiling strategy that is not only puzzling from an evolutionary perspective, but also hitherto unknown among shelled gastropods. The terrestrial gastropod Opisthostoma vermiculum sp. nov. generates a shell with: (i) four discernable coiling axes, (ii) body whorls that thrice detach and twice reattach to preceding whorls without any reference support, and (iii) detached whorls that coil around three secondary axes in addition to their primary teleoconch axis. As the coiling strategies of individuals were found to be generally consistent throughout, this species appears to possess an unorthodox but rigorously defined set of developmental instructions. Although the evolutionary origins of O. vermiculum and its shell's functional significance can be elucidated only once fossil intermediates and live individuals are found, its bewildering morphology suggests that we still lack an understanding of relationships between form and function in certain taxonomic groups.
    Matched MeSH terms: Biological Evolution*
  18. Schilthuizen M, van Til A, Salverda M, Liew TS, James SS, bin Elahan B, et al.
    Evolution, 2006 Sep;60(9):1851-8.
    PMID: 17089969
    Genetic divergence in geographically isolated populations is a prerequisite for allopatric speciation, one of the most common modes of speciation. In ecologically equivalent populations existing within a small, environmentally homogeneous area, an important role for environmentally neutral divergence is often found or inferred. We studied a species complex of conspicuously shaped Opisthostoma land snails on scattered limestone outcrops within a small area of lowland rainforest in Borneo. We used shell morphometrics, mitochondrial and nuclear DNA sequences, and marks of predation to study the factors involved in allopatric divergence. We found that a striking geographic divergence exists in shell morphology, which is partly associated with neutral genetic divergence. We also found geographic differentiation in the behavior of the snails' invertebrate predator and evidence of an evolutionary interaction between aspects of shell shape and predator behavior. Our study shows that adaptation to biotic aspects of the environment may play a more important role in allopatric speciation than previously suspected, even on a geographically very small scale.
    Matched MeSH terms: Biological Evolution*
  19. Schilthuizen M, Davison A
    Naturwissenschaften, 2005 Nov;92(11):504-15.
    PMID: 16217668
    The direction that a snail (Mollusca: Gastropoda) coils, whether dextral (right-handed) or sinistral (left-handed), originates in early development but is most easily observed in the shell form of the adult. Here, we review recent progress in understanding snail chirality from genetic, developmental and ecological perspectives. In the few species that have been characterized, chirality is determined by a single genetic locus with delayed inheritance, which means that the genotype is expressed in the mother's offspring. Although research lags behind the studies of asymmetry in the mouse and nematode, attempts to isolate the loci involved in snail chirality have begun, with the final aim of understanding how the axis of left-right asymmetry is established. In nature, most snail taxa (>90%) are dextral, but sinistrality is known from mutant individuals, populations within dextral species, entirely sinistral species, genera and even families. Ordinarily, it is expected that strong frequency-dependent selection should act against the establishment of new chiral types because the chiral minority have difficulty finding a suitable mating partner (their genitalia are on the 'wrong' side). Mixed populations should therefore not persist. Intriguingly, however, a very few land snail species, notably the subgenus Amphidromus sensu stricto, not only appear to mate randomly between different chiral types, but also have a stable, within-population chiral dimorphism, which suggests the involvement of a balancing factor. At the other end of the spectrum, in many species, different chiral types are unable to mate and so could be reproductively isolated from one another. However, while empirical data, models and simulations have indicated that chiral reversal must sometimes occur, it is rarely likely to lead to so-called 'single-gene' speciation. Nevertheless, chiral reversal could still be a contributing factor to speciation (or to divergence after speciation) when reproductive character displacement is involved. Understanding the establishment of chirality, the preponderance of dextral species and the rare instances of stable dimorphism is an important target for future research. Since the genetics of chirality have been studied in only a few pulmonate species, we also urge that more taxa, especially those from the sea, should be investigated.
    Matched MeSH terms: Biological Evolution*
  20. Fleagle JG
    Folia Primatol., 1976;26(4):245-69.
    PMID: 1010498
    Wild, adult siamang were observed for over 800 h in lowland dipterocarp forest in the Krau Game Reserve, Pahang, West Malaysia. Siamang use four patterns of locomotion: brachiation, climbing, bipedalism and leaping. The pattern of locomotion used by the siamang varies with the size of arboreal supports and with major behavioral activity. Travel is primarily by brachiation along large boughs. Locomotion during feeding is primarily climbing among small branches. In feeding, siamang use suspensory postures among small supports and seated postures on large supports. Comparison of siamang locomotion and posture with that of other apes suggest that quadramanous climbing during feeding is the basic hominoid locomotor adaptation.
    Matched MeSH terms: Biological Evolution*
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