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1.
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The rate of allelism of lethal genes in a geographically structured population 总被引:2,自引:1,他引:1 下载免费PDF全文
Yokoyama S 《Genetics》1979,93(1):245-262
The expected rate of allelism, E[I(x)], of lethal genes between two colonies with distance x in a structured population is studied by using one- and two-dimensional stepping-stone models. It is shown that E[I(x)] depends on the magnitude of selection in heterozygous condition (h), the rate of migration among adjacent colonies (m), the number of loci which produce lethal mutations (n) and the effective population size of each colony (N).——E[I(x)] always decreases with distance x. The rate of decrease is affected strongly by the magnitude of m. The rate of decrease is faster when m is small. E[I(x)] also decreases with increasing N and n. The effect of h on E[I(x)] is somewhat complicated. However, E[I(0)] is always smaller when h is small than when it is large.——For large x, the following approximate formulae may be obtained: (see PDF) where q and Var (q) are the mean and the variance of gene frequencies in each colony, t is approximated as t=h, (see PDF), -h for the partially recessive, completely recessive, and overdominant lethals, respectively, and C0 is a function of m and t. It is clear that E[I(x)] declines exponentially with x in a one-dimensional habitat. The decrease E[I(x)] is faster in a two-dimensional habitat than in a one-dimensional habitat. The present result is applied to some of the existing data and the estimation of population parameters is also discussed. 相似文献
3.
Cataglyphis
fisheri
sp. n. is described and illustrated from the United Arab Emirates, Oman and Kingdom of Saudi Arabia based on the worker caste. It belongs to the Cataglyphis
pallida-group which is recorded for the first time from the Arabian Peninsula. Cataglyphis
fisheri
sp. n. is similar to Cataglyphis
pallida Mayr, 1877 from Kazakhstan. Differential diagnosis between these two species is given and a key to the species of the Cataglyphis
pallida-group is presented. Cataglyphis
laylae Collingwood, 2011 is treated as a junior synonym of Cataglyphis
saharae Santschi, 1929. Cataglyphis
flavobrunnea Collingwood & Agosti, 1996 is redescribed and a lectotype for this species is designated. 相似文献
4.
Michel Sartori 《ZooKeys》2014,(445):97-106
The type material of Epeorella
borneonia Ulmer, 1939, the sole species of the genus Epeorella Ulmer, 1939 is reinvestigated and a lectotype (male imago) is designated. Based on several morphological structures, the synonymy with Epeorus Eaton, 1881 (Rhithrogeninae) is rejected. Epeorella stat. prop., known only at the winged stages, belongs to the subfamily Ecdyonurinae, and is a probable endemic of the island of Borneo. The newly erected genus Darthus Webb & McCafferty, 2007, also endemic to Borneo and only known by one species at the nymphal stage, is shown to be a junior subjective synonym of Epeorella. The new combination Epeorella
vadora (Webb & McCafferty, 2007) is proposed for the species. The distribution of known heptageniid species from the Sunda Islands is discussed. 相似文献
5.
A finite diploid population, observed at times t = 0, 1, 2,…, is studied. An individual is said to be in age group i at time t if its age is between i and i + 1 units at that time, where i ? 1. It is assumed that the number of individuals in a particular age-sex class is the same for every t and that the probability that a male offspring was produced by a mating of a male in age group i and a female in age group j is pijm (with a corresponding probability pfij for a female offspring), regardless of when the individual is born. The probability of ultimate fixation of an allele A1 and the inbreeding effective number, for large populations, is calculated under the further assumptions that A1 is neutral and that mating is random, given the ages of the mates. 相似文献
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Junfeng Zhang 《ZooKeys》2012,(238):57-76
A pair of fly impressions is described as a new species of a new genus, Orientisargus illecebrosus
gen. et sp. n., referred to a new family Orientisargidae
fam. n. within Archisargoidea of Brachycera, Diptera. The systematic position of Orientisargidae is discussed. Daohugosargus
gen. n. is proposed for Sharasargus eximius KY Zhang et al., 2008. Uranorhagionidae is a junior synonym for Archisargidae. Meanwhile, Mostovskisarginae is a junior synonym for Uranorhagionidae. Mostovskisargus JF Zhang, 2010 and Strenorhagio KY Zhang et al., 2010 are synonymized with Uranorhagio KY Zhang et al., 2010. Uranorhagio includes three species: Uranorhagio asymmetricus (KY Zhang et al., 2010), comb. n., Uranorhagio daohugouensis KY Zhang et al., 2010 and Uranorhagio deviatus (KY Zhang et al., 2010), comb. n.
Strenorhagio grimaldi KY Zhang et al., 2010 is synonymous with Uranorhagio deviatus. Mostovskisargus portentosus JF Zhang, 2010, Mostovskisargus signatus JF Zhang, 2010 and Strenorhagio conjugovenius KY Zhang et al., 2010 are synonymous with Uranorhagio asymmetricus. Brevisolva KY Zhang et al., 2010 is a junior synonym for Mesosolva Hong, 1983. A new specific name, Mesosolva zhangae
nom. n., is proposed for Brevisolva daohugouensis KY Zhang et al., 2010. Mesosolva jurassica KY Zhang et al., 2010 should be synonymized under Mostovskisargus sinensis KY Zhang et al., 2010. Sinallomyia nom. n. is proposed for Allomyia Ren, 1998. The systematic positions for Helempis eucalla Ren, 1998, Helempis yixianensis Ren, 1998, Pauromyia oresbia Ren, 1998 and Sinallomyia ruderalis (Ren, 1998) are reassessed. These taxa belong to Archisargidae rather than to Tabanidae, Rhagionidae and Protempididae, respectively. 相似文献
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Xiao-Guo Xiang Wei-Tao Jin De-Zhu Li André Schuiteman Wei-Chang Huang Jian-Wu Li Xiao-Hua Jin Zhen-Yu Li 《PloS one》2014,9(1)
Collabieae (Orchidaceae) is a long neglected tribe with confusing tribal and generic delimitation and little-understood phylogenetic relationships. Using plastid matK, psaB, rbcL, and trnH-psbA DNA sequences and morphological evidence, the phylogenetic relationships within the tribe Collabieae were assessed as a basis for revising their tribal and generic delimitation. Collabieae (including the previously misplaced mycoheterotrophic Risleya) is supported as monophyletic and nested within a superclade that also includes Epidendreae, Podochileae, Cymbidieae and Vandeae. Risleya is nested in Collabiinae and sister to Chrysoglossum, a relationship which, despite their great vegetative differences, is supported by floral characters. Ania is a distinct genus supported by both morphological and molecular evidence, while redefined Tainia includes Nephelaphyllum and Mischobulbum. Calanthe is paraphyletic and consists four clades; the genera Gastrorchis, Phaius and Cephalantheropsis should be subsumed within Calanthe. Calanthe sect. Ghiesbreghtia is nested within sect. Calanthe, to which the disputed Calanthe delavayi belongs as well. Our results indicate that, in Collabieae, habit evolved from being epiphytic to terrestrial. 相似文献
10.
A new species of Hycleus belonging to the phaleratus group, and close to Hycleus
phaleratus, is described. The new species, Hycleus
marcipoli, is distributed in China (Gansu and Taiwan), Laos, and northern Thailand. A key to the Chinese species of this group is presented. 相似文献
11.
The objective of this study is to provide a detailed taxonomic resource for identifying and studying ants in the genus Pheidole that have established beyond their native ranges. There is an increasing need for systematists to study taxa of specific concern to 21st century environmental, food security and public health challenges. Systematics has an important role to play in both the theoretical and applied disciplines of invasion biology. Few invaders impact terrestrial ecosystems more than ants. Among the world’s 100 worst invasive species is the cosmopolitan and highly destructive Pheidole
megacephala (Fabricius). Accurate identification of Pheidole
megacephala is imperative for the success of screening, management and eradication programs designed to protect native ecosystems from the impacts of this destructive species. However, accurate identification of Pheidole species is difficult because of their taxonomic diversity, dimorphic worker caste and lack of taxonomic resources. Illustrated keys are included, along with the taxonomic history, taxonomic diagnoses, biological notes and risk statements for the 14 most invasive members of the genus. Global distribution maps based on over 14,000 specimen and literature records are presented for each species. These results of this work will facilitate identification of pest species, determination of climatic and habitat requirements, discovery of pest origins, horizon scanning and assessment of invasion pathways. The following new synonym is proposed, with the senior synonym listed first and the junior synonyms in parentheses: Pheidole
indica Mayr (= Pheidole
teneriffana Forel, and its synonyms Pheidole
taina Aguayo and Pheidole
voeltzkowii Forel). Pheidole
navigans Forel, stat. rev., stat. n. is removed from synonymy and elevated to species rank. It is proposed that records of Pheidole
moerens Forel outside of the Mesoamerica and the Caribbean refer instead to Pheidole
navigans or other heterospecific taxa in the Pheidole
flavens species complex. We propose that the names Pheidole
anastasii Emery and Pheidole
floridana Emery have been widely misapplied to North American outdoor records of Pheidole
bilimeki Mayr. It is suggested that the synonymy of Pheidole
lauta Wheeler be transferred from Pheidole
floridana Emery to Pheidole
bilimeki Mayr. 相似文献
12.
Material of the paederine genus Domene Fauvel, 1873 from China is examined. Nine species were identified, four of them described previously, one unnamed (represented exclusively by females), and four are newly described: Domene
cultrata
sp. n. (Gansu, Hubei, Shaanxi); Domene
cuspidata
sp. n. (Gansu, Shaanxi, Sichuan); Domene
chenae
sp. n. (Guangxi); Domene
reducta
sp. n. (Sichuan). A lectotype is designated for Domene
reitteri Koch, 1939; a neotype is designated for Domene
chenpengi Li, 1990. Domene
dersuuzalai Gusarov, 1992 is placed in synonymy with Domene
chenpengi. Previous records of two Japanese species from China are most likely based on misidentifications and considered erroneous. Thus, the Domene fauna of China is currently composed of twelve described species. A key to the Domene species of China is provided. The distributions of eleven species are mapped. 相似文献
13.
The genus Eadmuna Schaus, 1928 is revised to include four species. Eadmuna
guianensis
sp. n., is described from French Guiana and Guyana. The holotype of Perophora
pulverula Schaus, 1896, currently placed in Cicinnus Blanchard, 1852, is determined to be a previously unrecognized female Eadmuna, and is transferred accordingly as Eadmuna
pulverula
comb. n..
Eadmuna
paloa Schaus, 1933, rev. status, is removed from synonymy with the type species Eadmuna
esperans (Schaus, 1905). Eadmuna
esperans, Eadmuna
paloa, and Eadmuna
pulverula may be of conservation concern due to their limited extent of occurrence and endemicity to the highly imperiled Brazilian Atlantic forest. 相似文献
14.
The genus Zachobiella Banks, 1920 is reviewed and a new species Zachobiella
yunanica
sp. n. described from China. All species found in China are redescribed, and Zachobiella
submarginata Esben-Petersen, 1929 is recorded from China for the first time. A key to the adults of Zachobiella is provided. 相似文献
15.
Three species of the genus Xenocerogria Merkl, 2007 have been recorded in China, Xenocerogria
feai (Borchmann, 1911), Xenocerogria
ignota (Borchmann, 1941) and Xenocerogria
ruficollis (Borchmann, 1912). Xenocera
xanthisma Chen, 2002 is proposed as a junior synonym of Xenocerogria
ruficollis. Lectotype of Xenocerogria
ignota is designated, and the species is transferred to the genus Lagria Fabricius, 1775. New Chinese province records of Xenocerogria
ruficollis are provided. 相似文献
16.
Stéphanie Boisnard Youfang Zhou Li Sylvie Arnaise Gregory Sequeira Xavier Raffoux Adela Enache-Angoulvant Monique Bolotin-Fukuhara Cécile Fairhead 《PloS one》2015,10(10)
Candida glabrata is an apparently asexual haploid yeast that is phylogenetically closer to Saccharomyces cerevisiae than to Candida albicans. Its genome contains three MAT-like cassettes, MAT, which encodes either MATa or MATalpha information in different strains, and the additional loci, HML and HMR. The genome also contains an HO gene homolog, but this yeast has never been shown to switch mating-types spontaneously, as S. cerevisiae does. We have recently sequenced the genomes of the five species that, together with C. glabrata, make up the Nakaseomyces clade. All contain MAT-like cassettes and an HO gene homolog. In this work, we express the HO gene of all Nakaseomyces and of S. cerevisiae in C. glabrata. All can induce mating-type switching, but, despite the larger phylogenetic distance, the most efficient endonuclease is the one from S. cerevisiae. Efficient mating-type switching in C. glabrata is accompanied by a high cell mortality, and sometimes results in conversion of the additional cassette HML. Mortality probably results from the cutting of the HO recognition sites that are present, in HML and possibly HMR, contrary to what happens naturally in S. cerevisiae. This has implications in the life-cycle of C. glabrata, as we show that efficient MAT switching is lethal for most cells, induces chromosomal rearrangements in survivors, and that the endogenous HO is probably rarely active indeed. 相似文献
17.
A new delphacid (Hemiptera, Fulgoromorpha, Delphacidae) species, Mestus
cruciatus
sp. n. is described based on specimens from Yunnan Province, China. Habitus photos and illustrations of male genitalia are provided. The Mestus species and phylogenetic arrangement of this genus is discussed. A key to the species of Mestus is also provided. 相似文献
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The present study is based on oribatid mite material (Acari, Oribatida) collected during the German Expedition in 2011 in Peru. An annotated checklist of identified oribatid mites, including 16 species from 14 genera and 8 families, is provided. Thirteen species and two genera (Notohermannia, Zetomimus) are recorded for the first time in Peru; the genus Notohermannia and species Notohermannia
obtusa are recorded for the first time in the Neotropical region. A new species of the genus Pergalumna (Galumnidae), Pergalumna
paraboliviana
sp. n., is described. The new species is most similar to Pergalumna
boliviana Ermilov, 2013 from Bolivia, however, it differs from the latter by the body size, morphology of porose areas A1 and the presence of interlamellar setae. 相似文献
20.
Svatopluk Bíly 《ZooKeys》2013,(304):17-47
Revision of the Neotropical genera of the subtribe Anthaxiina Gory & Laporte, 1839 (Coleoptera, Buprestidae, Buprestinae, Anthaxiini). Five new genera are described: Anthaxita
gen. n., Charlesina
gen. n., Cobosina
gen. n., Marikia
gen. n. and Sanchezia
gen. n. Genus Agrilaxia Kerremans, 1903 is divided into two subgenera: Agrilaxia and Costiptera
subgen. n. and the genus Bilyaxia Hołyński, 1989 is divided into three subgenera: Bilyaxia, Paraguayetta
subgen. n. and Tomasia
subgen. n. One new species is described: Anthaxita peruviana
sp. n., and two informal species-groups are suggested within Agrilaxia (Costiptera
subgen. n.): Agrilaxia (Costiptera) modesta (Kerremans, 1897) species-group and Agrilaxia (Costiptera) occidentalis (Kerremans, 1900) species-group. Lectotype is designated for Agrilaxia mrazi Obenberger, 1932. A key of all genera/subgenera is provided and all treated taxa are illustrated. 相似文献