Displaying publications 1 - 20 of 171 in total

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  1. Sea water shaping the freshwater biota: Hidden diversity and biogeographic history in the Paracanthocobitis zonalternans species complex (Teleostei: Nemacheilidae) in western Southeast Asia
    Bohlen J, Dvořák T, Šlechta V, Šlechtová V
    Mol Phylogenet Evol, 2020 07;148:106806.
    PMID: 32247884 DOI: 10.1016/j.ympev.2020.106806
    Western Southeast Asia is hosting one of the world's most diverse faunas, and one of the reasons for this huge diversity is the complex geologic past of the area, increasing the frequency of isolation and expansion events over evolutionary time scale. As an example case, the present study reveals the phylogeny and biogeographic history of the Paracanthocobitis zonalternans species complex, small benthic freshwater fish (Teleostei: Nemacheilidae) that are commonly occurring across western Southeast Asia (from central Myanmar through western and southern Thailand to northern Malaysia). The group is particularly interesting since it occurs in three biogeographic subdivisions (Indian, Indochinese, Malay/Sundaic) and across all of the major biogeographic barriers in the region. Basing on mitochondrial and nuclear sequence data of 93 samples from about 50 localities we found six major clades, most with exclusive geographic distribution. Divergence time dated the origin of the P. zonalternans species complex to early Miocene (17.8 MYA) and a biogeographic analysis identified the Tenasserim region as the ancestral region. From this region the fish spread during periods of lowered global sea level, particularly during late Miocene (11-8 MYA) northwards into all Burmese river basins and southwards into south Thailand and northern Malaysia. Besides lowered global sea level periods, local stream capture events allowed the complex to expand, e.g. into the Mae Klong basin. Strong fragmentations during periods with elevated sea level during the Pliocene and Pleistocene repeatedly restricted populations to refuges and shaped the observed major lineages. Our results document a higher diversity within the P. zonalternans species complex than formerly believed and a strong impact of global sea level on its evolutionary history. Low sea levels promoted dispersal and elevated sea levels fragmentation events. A very similar impact of sea level changes can be expected in all stationary fauna (freshwater and terrestrial) in all non-mountainous coastal regions worldwide.
    Matched MeSH terms: Biological Evolution
  2. Species delimitation and biogeography of a southern hemisphere liverwort clade, Frullania subgenus Microfrullania (Frullaniaceae, Marchantiophyta)
    Carter BE, Larraín J, Manukjanová A, Shaw B, Shaw AJ, Heinrichs J, et al.
    Mol Phylogenet Evol, 2017 02;107:16-26.
    PMID: 27744015 DOI: 10.1016/j.ympev.2016.10.002
    Frullania subgenus Microfrullania is a clade of ca. 15 liverwort species occurring in Australasia, Malesia, and southern South America. We used combined nuclear and chloroplast sequence data from 265 ingroup accessions to test species circumscriptions and estimate the biogeographic history of the subgenus. With dense infra-specific sampling, we document an important role of long-distance dispersal in establishing phylogeographic patterns of extant species. At deeper time scales, a combination of phylogenetic analyses, divergence time estimation and ancestral range estimation were used to reject vicariance and to document the role of long-distance dispersal in explaining the evolution and biogeography of the clade across the southern Hemisphere. A backbone phylogeny for the subgenus is proposed, providing insight into evolution of morphological patterns and establishing the basis for an improved sectional classification of species within Microfrullania. Several species complexes are identified, the presence of two undescribed but genetically and morphologically distinct species is noted, and previously neglected names are discussed.
    Matched MeSH terms: Biological Evolution
  3. Fulltext The impact of A. R. Wallace's Sarawak Law paper reassessed
    van Wyhe J
    Stud Hist Philos Biol Biomed Sci, 2016 Dec;60:56-66.
    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*
  4. Sex Differences in Mate Preferences Across 45 Countries: A Large-Scale Replication
    Walter KV, Conroy-Beam D, Buss DM, Asao K, Sorokowska A, Sorokowski P, et al.
    Psychol Sci, 2020 Apr;31(4):408-423.
    PMID: 32196435 DOI: 10.1177/0956797620904154
    Considerable research has examined human mate preferences across cultures, finding universal sex differences in preferences for attractiveness and resources as well as sources of systematic cultural variation. Two competing perspectives-an evolutionary psychological perspective and a biosocial role perspective-offer alternative explanations for these findings. However, the original data on which each perspective relies are decades old, and the literature is fraught with conflicting methods, analyses, results, and conclusions. Using a new 45-country sample (N = 14,399), we attempted to replicate classic studies and test both the evolutionary and biosocial role perspectives. Support for universal sex differences in preferences remains robust: Men, more than women, prefer attractive, young mates, and women, more than men, prefer older mates with financial prospects. Cross-culturally, both sexes have mates closer to their own ages as gender equality increases. Beyond age of partner, neither pathogen prevalence nor gender equality robustly predicted sex differences or preferences across countries.
    Matched MeSH terms: Biological Evolution
  5. Evaluating Frugivore-fruit Interactions Using Avian Eye Modelling
    Fadzly N, Burns KC, Zuharah WF
    Trop Life Sci Res, 2013 Dec;24(2):31-50.
    PMID: 24575247 MyJurnal
    Fruit phenotypes are often hypothesised to be affected by selection by frugivores. Here, we tested two hypotheses concerning frugivore-fruit interactions from the perspective of fruit colours. We measured the spectral properties of 26 fruits and the associated leaves of plants from 2 islands in New Zealand. Visual observations were also performed to record the birds that fed on the fruits. First, we tested the fruit-foliage hypothesis, where fruit colours are assumed to be evolutionarily constrained by their own leaf colour to maximise colour contrast and fruit conspicuousness. We ran a null model analysis comparing fruit colour contrast using an avian eye model. Second, we tested the frugivore specificity hypothesis, where specific fruit colours are thought to be connected with a specific bird frugivore. We performed a regression on the number of bird visits against the fruit colour in tetrahedral colour space based on an avian eye calculation using Mantel's test. The results show that fruit colours are not constrained by their own leaf colours. There is also no relationship or pattern suggesting a link between a specific fruit colour and specific bird visitors. We suggest that although fruit colour is one of the most highly discussed components, it is not the most important single deciding factor in frugivore fruit selection.
    Matched MeSH terms: Biological Evolution
  6. Fulltext Interactions between all pairs of neighboring trees in 16 forests worldwide reveal details of unique ecological processes in each forest, and provide windows into their evolutionary histories
    Wills C, Wang B, Fang S, Wang Y, Jin Y, Lutz J, et al.
    PLoS Comput Biol, 2021 Apr;17(4):e1008853.
    PMID: 33914731 DOI: 10.1371/journal.pcbi.1008853
    When Darwin visited the Galapagos archipelago, he observed that, in spite of the islands' physical similarity, members of species that had dispersed to them recently were beginning to diverge from each other. He postulated that these divergences must have resulted primarily from interactions with sets of other species that had also diverged across these otherwise similar islands. By extrapolation, if Darwin is correct, such complex interactions must be driving species divergences across all ecosystems. However, many current general ecological theories that predict observed distributions of species in ecosystems do not take the details of between-species interactions into account. Here we quantify, in sixteen forest diversity plots (FDPs) worldwide, highly significant negative density-dependent (NDD) components of both conspecific and heterospecific between-tree interactions that affect the trees' distributions, growth, recruitment, and mortality. These interactions decline smoothly in significance with increasing physical distance between trees. They also tend to decline in significance with increasing phylogenetic distance between the trees, but each FDP exhibits its own unique pattern of exceptions to this overall decline. Unique patterns of between-species interactions in ecosystems, of the general type that Darwin postulated, are likely to have contributed to the exceptions. We test the power of our null-model method by using a deliberately modified data set, and show that the method easily identifies the modifications. We examine how some of the exceptions, at the Wind River (USA) FDP, reveal new details of a known allelopathic effect of one of the Wind River gymnosperm species. Finally, we explore how similar analyses can be used to investigate details of many types of interactions in these complex ecosystems, and can provide clues to the evolution of these interactions.
    Matched MeSH terms: Biological Evolution*
  7. Fulltext The vulnerability assessment and obstacle factor analysis of urban agglomeration along the Yellow River in China from the perspective of production-living-ecological space
    Yang L, Meng H, Wang J, Wu Y, Zhao Z
    PLoS One, 2024;19(4):e0299729.
    PMID: 38578727 DOI: 10.1371/journal.pone.0299729
    Urban agglomerations are sophisticated territorial systems at the mature stage of city development that are concentrated areas of production and economic activity. Therefore, the study of vulnerability from the perspective of production-living-ecological space is crucial for the sustainable development of the Yellow River Basin and global urban agglomerations. The relationship between productivity, living conditions, and ecological spatial quality is fully considered in this research. By constructing a vulnerability evaluation index system based on the perspectives of production, ecology, and living space, and adopting the entropy value method, comprehensive vulnerability index model, and obstacle factor diagnostic model, the study comprehensively assesses the vulnerability of the urban agglomerations along the Yellow River from 2001 to 2020. The results reveal that the spatial differentiation characteristics of urban agglomeration vulnerability are significant. A clear three-level gradient distribution of high, medium, and low degrees is seen in the overall vulnerability; these correspond to the lower, middle, and upper reaches of the Yellow River Basin, respectively. The percentage of cities with higher and moderate levels of vulnerability did not vary from 2001 to 2020, while the percentage of cities with high levels of vulnerability did. The four dimensions of economic development, leisure and tourism, resource availability, and ecological pressure are the primary determinants of the urban agglomeration's vulnerability along the Yellow River. And the vulnerability factors of various urban agglomerations showed a significant evolutionary trend; the obstacle degree values have declined, and the importance of tourism and leisure functions has gradually increased. Based on the above conclusions, we propose several suggestions to enhance the quality of urban development along the Yellow River urban agglomeration. Including formulating a three-level development strategy, paying attention to ecological and environmental protection, developing domestic and foreign trade, and properly planning and managing the tourism industry.
    Matched MeSH terms: Biological Evolution
  8. Characterisation of the mitochondrial genome and phylogenetic analysis of Toxocara apodemi (Nematoda: Ascarididae)
    Gao Y, Hu Y, Xu S, Liang H, Lin H, Yin TH, et al.
    J Helminthol, 2024 Apr 15;98:e33.
    PMID: 38618902 DOI: 10.1017/S0022149X24000221
    We first sequenced and characterised the complete mitochondrial genome of Toxocara apodeme, then studied the evolutionary relationship of the species within Toxocaridae. The complete mitochondrial genome was amplified using PCR with 14 specific primers. The mitogenome length was 14303 bp in size, including 12 PCGs (encoding 3,423 amino acids), 22 tRNAs, 2 rRNAs, and 2 NCRs, with 68.38% A+T contents. The mt genomes of T. apodemi had relatively compact structures with 11 intergenic spacers and 5 overlaps. Comparative analyses of the nucleotide sequences of complete mt genomes showed that T. apodemi had higher identities with T. canis than other congeners. A sliding window analysis of 12 PCGs among 5 Toxocara species indicated that nad4 had the highest sequence divergence, and cox1 was the least variable gene. Relative synonymous codon usage showed that UUG, ACU, CCU, CGU, and UCU most frequently occurred in the complete genomes of T. apodemi. The Ka/Ks ratio showed that all Toxocara mt genes were subject to purification selection. The largest genetic distance between T. apodemi and the other 4 congeneric species was found in nad2, and the smallest was found in cox2. Phylogenetic analyses based on the concatenated amino acid sequences of 12 PCGs demonstrated that T. apodemi formed a distinct branch and was always a sister taxon to other congeneric species. The present study determined the complete mt genome sequences of T. apodemi, which provide novel genetic markers for further studies of the taxonomy, population genetics, and systematics of the Toxocaridae nematodes.
    Matched MeSH terms: Biological Evolution
  9. Fulltext Origin and diversity of an underutilized fruit tree crop, cempedak (Artocarpus integer, Moraceae)
    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*
  10. On tapir ecology, evolution and conservation: what we know and future perspectives-part I
    Gonçalves DA Silva A, Campos-Arceiz A, Zavada MS
    Integr Zool, 2012 Dec;7(4):329-330.
    PMID: 23253364 DOI: 10.1111/1749-4877.12015
    Matched MeSH terms: Biological Evolution*
  11. Evolutionary history of Dengue virus type 4: insights into genotype phylodynamics
    Villabona-Arenas CJ, Zanotto PM
    Infect Genet Evol, 2011 Jul;11(5):878-85.
    PMID: 21335103 DOI: 10.1016/j.meegid.2011.02.007
    Dengue virus type 4 (DENV-4) circulates in tropical and subtropical countries from Asia and the Americas. Despite the importance of dengue virus distribution, little is known about the worldwide viral spread. Following a Bayesian phylogenetic approach we inferred the evolutionary history of 310 isolates sampled from 37 countries during the time period 1956-2008 and the spreading dynamics for genotypes I and II. The region (tropical rainforest biome) comprised by Malaysia-Thailand was the most likely ancestral area from which the serotype has originated and spread. Interestingly, cross-correlation analysis on demographic time series with the Asian sequences showed a statistically significant negative correlation that could be suggestive of competition among genotypes within the same serotype.
    Matched MeSH terms: Biological Evolution*
  12. Fulltext Natural selection and local adaptation of blood pressure regulation and their perspectives on precision medicine in hypertension
    Hoh BP, Abdul Rahman T, Yusoff K
    Hereditas, 2019;156:1.
    PMID: 30636949 DOI: 10.1186/s41065-019-0080-1
    Prevalence of hypertension (HTN) varies substantially across different populations. HTN is not only common - affecting at least one third of the world's adult population - but is also the most important driver for cardiovascular diseases. Yet up to a third of hypertensive patients are resistant to therapy, contributed by secondary hypertension but more commonly the hitherto inability to precisely predict response to specific antihypertensive agents. Population and individual genomics information could be useful in guiding the selection and predicting the response to treatment - an approach known as precision medicine. However this cannot be achieved without the knowledge of genetic variations that influence blood pressure (BP). A number of evolutionary factors including population demographics and forces of natural selection may be involved. This article explores some ideas on how natural selection influences BP regulation in ethnically and geographically diverse populations that could lead to them being susceptible to HTN. We explore how such evolutionary factors could impact the implementation of precision medicine in HTN. Finally, in order to ensure the success of precision medicine in HTN, we call for more initiatives to understand the genetic architecture within and between diverse populations with ancestry from different parts of the world, and to precisely classify the intermediate phenotypes of HTN.
    Matched MeSH terms: Biological Evolution
  13. A New Framework for Analysis of Coevolutionary Systems-Directed Graph Representation and Random Walks
    Chong SY, Tiňo P, He J, Yao X
    Evol Comput, 2019;27(2):195-228.
    PMID: 29155606 DOI: 10.1162/evco_a_00218
    Studying coevolutionary systems in the context of simplified models (i.e., games with pairwise interactions between coevolving solutions modeled as self plays) remains an open challenge since the rich underlying structures associated with pairwise-comparison-based fitness measures are often not taken fully into account. Although cyclic dynamics have been demonstrated in several contexts (such as intransitivity in coevolutionary problems), there is no complete characterization of cycle structures and their effects on coevolutionary search. We develop a new framework to address this issue. At the core of our approach is the directed graph (digraph) representation of coevolutionary problems that fully captures structures in the relations between candidate solutions. Coevolutionary processes are modeled as a specific type of Markov chains-random walks on digraphs. Using this framework, we show that coevolutionary problems admit a qualitative characterization: a coevolutionary problem is either solvable (there is a subset of solutions that dominates the remaining candidate solutions) or not. This has an implication on coevolutionary search. We further develop our framework that provides the means to construct quantitative tools for analysis of coevolutionary processes and demonstrate their applications through case studies. We show that coevolution of solvable problems corresponds to an absorbing Markov chain for which we can compute the expected hitting time of the absorbing class. Otherwise, coevolution will cycle indefinitely and the quantity of interest will be the limiting invariant distribution of the Markov chain. We also provide an index for characterizing complexity in coevolutionary problems and show how they can be generated in a controlled manner.
    Matched MeSH terms: Biological Evolution*
  14. Fulltext Genomic reconnaissance of clinical isolates of emerging human pathogen Mycobacterium abscessus reveals high evolutionary potential
    Choo SW, Wee WY, Ngeow YF, Mitchell W, Tan JL, Wong GJ, et al.
    Sci Rep, 2014;4:4061.
    PMID: 24515248 DOI: 10.1038/srep04061
    Mycobacterium abscessus (Ma) is an emerging human pathogen that causes both soft tissue infections and systemic disease. We present the first comparative whole-genome study of Ma strains isolated from patients of wide geographical origin. We found a high proportion of accessory strain-specific genes indicating an open, non-conservative pan-genome structure, and clear evidence of rapid phage-mediated evolution. Although we found fewer virulence factors in Ma compared to M. tuberculosis, our data indicated that Ma evolves rapidly and therefore should be monitored closely for the acquisition of more pathogenic traits. This comparative study provides a better understanding of Ma and forms the basis for future functional work on this important pathogen.
    Matched MeSH terms: Biological Evolution*
  15. Evolutionary relationships of endemic/epidemic and sylvatic dengue viruses
    Wang E, Ni H, Xu R, Barrett AD, Watowich SJ, Gubler DJ, et al.
    J Virol, 2000 Apr;74(7):3227-34.
    PMID: 10708439
    Endemic/epidemic dengue viruses (DEN) that are transmitted among humans by the mosquito vectors Aedes aegypti and Aedes albopictus are hypothesized to have evolved from sylvatic DEN strains that are transmitted among nonhuman primates in West Africa and Malaysia by other Aedes mosquitoes. We tested this hypothesis with phylogenetic studies using envelope protein gene sequences of both endemic/epidemic and sylvatic strains. The basal position of sylvatic lineages of DEN-1, -2, and -4 suggested that the endemic/epidemic lineages of these three DEN serotypes evolved independently from sylvatic progenitors. Time estimates for evolution of the endemic/epidemic forms ranged from 100 to 1,500 years ago, and the evolution of endemic/epidemic forms represents relatively recent events in the history of DEN evolution. Analysis of envelope protein amino acid changes predicted to have accompanied endemic/epidemic emergence suggested a role for domain III in adaptation to new mosquito and/or human hosts.
    Matched MeSH terms: Biological Evolution*
  16. Dissecting the Biology of Rafflesia Species: Current Progress and Future Directions Made Possible with High-Throughput Sequencing Data
    Mursyidah AK, Hafizzudin-Fedeli M, Nor Muhammad NA, Latiff A, Firdaus-Raih M, Wan KL
    Plant Cell Physiol, 2023 Apr 17;64(4):368-377.
    PMID: 36611267 DOI: 10.1093/pcp/pcad004
    The angiosperm Rafflesia exhibits a unique biology, including a growth strategy that involves endophytic parasitism of a specific host, with only the gigantic flower externally visible. The Rafflesia possesses many unique evolutionary, developmental and morphological features that are rooted in yet-to-be-explained physiological processes. Although studies on the molecular biology of Rafflesia are limited by sampling difficulties due to its rarity in the wild and the short life span of its flower, current advances in high-throughput sequencing technology have allowed for the genome- and transcriptome-level dissection of the molecular mechanisms behind the unique characteristics of this parasitic plant. In this review, we summarize major findings on the cryptic biology of Rafflesia and provide insights into future research directions. The wealth of data obtained can improve our understanding of Rafflesia species and contribute toward the conservation strategy of this endangered plant.
    Matched MeSH terms: Biological Evolution*
  17. Fulltext Resurrection of Bronchocela burmana Blanford, 1878 for the Green Crested Lizard (Squamata, Agamidae) of southern Myanmar
    Zug GR, Mulcahy DG, Vindum JV
    Zookeys, 2017.
    PMID: 28331413 DOI: 10.3897/zookeys.657.11600
    Recent fieldwork in southern Tanintharyi revealed the presence of a small Green Crested Lizard in the wet evergreen forest. We generated mtDNA sequence data (ND2) that demonstrates that this population's nearest relative is Bronchocela rayaensis Grismer et al., 2015 of Pulau Langkawi, northwestern Peninsular Malaysia and Phuket Island. Morphologically the Burmese Bronchocela shares many features with Bronchocela rayaensis, which potentially would make this recently described Thai-Malay species a synonym of Bronchocela burmana Blanford, 1878; however, we interpret the genetic and morphological differences to reflect evolutionary divergence and recommend the recognition of both species.
    Matched MeSH terms: Biological Evolution
  18. Microgeographic evolution of snail shell shape and predator behavior
    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. The 'human revolution' in lowland tropical Southeast Asia: the antiquity and behavior of anatomically modern humans at Niah Cave (Sarawak, Borneo)
    Barker G, Barton H, Bird M, Daly P, Datan I, Dykes A, et al.
    J Hum Evol, 2007 Mar;52(3):243-61.
    PMID: 17161859
    Recent research in Europe, Africa, and Southeast Asia suggests that we can no longer assume a direct and exclusive link between anatomically modern humans and behavioral modernity (the 'human revolution'), and assume that the presence of either one implies the presence of the other: discussions of the emergence of cultural complexity have to proceed with greater scrutiny of the evidence on a site-by-site basis to establish secure associations between the archaeology present there and the hominins who created it. This paper presents one such case study: Niah Cave in Sarawak on the island of Borneo, famous for the discovery in 1958 in the West Mouth of the Great Cave of a modern human skull, the 'Deep Skull,' controversially associated with radiocarbon dates of ca. 40,000 years before the present. A new chronostratigraphy has been developed through a re-investigation of the lithostratigraphy left by the earlier excavations, AMS-dating using three different comparative pre-treatments including ABOX of charcoal, and U-series using the Diffusion-Absorption model applied to fragments of bones from the Deep Skull itself. Stratigraphic reasons for earlier uncertainties about the antiquity of the skull are examined, and it is shown not to be an 'intrusive' artifact. It was probably excavated from fluvial-pond-desiccation deposits that accumulated episodically in a shallow basin immediately behind the cave entrance lip, in a climate that ranged from times of comparative aridity with complete desiccation, to episodes of greater surface wetness, changes attributed to regional climatic fluctuations. Vegetation outside the cave varied significantly over time, including wet lowland forest, montane forest, savannah, and grassland. The new dates and the lithostratigraphy relate the Deep Skull to evidence of episodes of human activity that range in date from ca. 46,000 to ca. 34,000 years ago. Initial investigations of sediment scorching, pollen, palynomorphs, phytoliths, plant macrofossils, and starch grains recovered from existing exposures, and of vertebrates from the current and the earlier excavations, suggest that human foraging during these times was marked by habitat-tailored hunting technologies, the collection and processing of toxic plants for consumption, and, perhaps, the use of fire at some forest-edges. The Niah evidence demonstrates the sophisticated nature of the subsistence behavior developed by modern humans to exploit the tropical environments that they encountered in Southeast Asia, including rainforest.
    Matched MeSH terms: Biological Evolution*
  20. Molecular evolution and epidemiology of dengue-3 viruses
    Lanciotti RS, Lewis JG, Gubler DJ, Trent DW
    J Gen Virol, 1994 Jan;75 ( Pt 1):65-75.
    PMID: 8113741
    The nucleic acid sequences of the pre-membrane/membrane and envelope protein genes of 23 geographically and temporally distinct dengue (DEN)-3 viruses were determined. This was accomplished by reverse transcriptase-PCR amplification of the structural genes followed by automated DNA sequence analysis. Comparison of nucleic acid sequences revealed that similarity among the viruses was greater than 90%. The similarity among deduced amino acids was between 95% and 100%, and in many cases identical amino acid substitutions occurred among viruses from similar geographical regions. Alignment of nucleic acid sequences followed by parsimony analysis allowed the generation of phylogenetic trees, demonstrating that geographically independent evolution of DEN-3 viruses had occurred. The DEN-3 viruses were separated into four genetically distinct subtypes. Subtype I consists of viruses from Indonesia, Malaysia, the Philippines and the South Pacific islands; subtype II consists of viruses from Thailand; subtype III consists of viruses from Sri Lanka, India, Africa and Samoa; subtype IV consists of viruses from Puerto Rico and the 1965 Tahiti virus. Phylogenetic analysis has also contributed to our understanding of the molecular epidemiology and worldwide distribution of DEN-3 viruses.
    Matched MeSH terms: Biological Evolution
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