scholarly journals A DNA investigation into the mysterious disappearance of the Rocky Mountain grasshopper, mega-pest of the 1800s

2017 ◽  
Author(s):  
W. Chapco ◽  
G. Litzenberger

The mysterious extinction of the Rocky Mountain Grasshopper, Melanoplus spretus, a major pest species on the prairies and plains of the 1800s, is truly a remarkable event in the history of agriculture. Recently, we obtained specimens of M. spretus from museums and from 400-year-old glacial deposits in Wyoming. We report success in obtaining mitochondrial DNA sequences from both sources. This permitted us to examine two issues surrounding the species’ disappearance. First, a long-standing view that M. spretus and the extant species Melanoplus sanguinipes are (if not phase transforms of one another) sister taxa, is disputed, but cannot be rejected with certainty. Interestingly, there is some evidence that suggests there may be a closer affinity with another member of the Mexicanus species-group, Melanoplus bruneri. Second, because M. spretus still possesses considerable nucleotide diversity (1.15 ± 0.19%), a depletion of variation cannot be considered a factor contributing to its demise.

Author(s):  
Klaus-Peter Koepfli ◽  
Jerry W. Dragoo ◽  
Xiaoming Wang

This chapter provides a review of the evolutionary and taxonomic history of the Musteloidea, which is the most species-rich superfamily of the Carnivora, containing approximately 30% of the extant species in the order. An up-to-date summary of knowledge on the evolutionary and taxonomic history and phylogenetic relationships of the Mephitidae, Ailuridae, Procyonidae and Mustelidae is provided. Multilocus DNA sequences have made a large impact on the understanding of phylogenetic relationships among the Musteloidea. Molecular data have revealed distinct families (Ailuridae and Mephitidae) within the Musteloidea and have illuminated new relationships based on tempo and patterns of evolution within the Procyonidae. Morphological data in conjunction with molecular data have been used to elucidate species boundaries within certain musteloid genera and have led to the discovery of a new species. Research studies published during the last 30 years have enriched and transformed our understanding of the evolution of musteloid biodiversity.


1992 ◽  
Vol 70 (3) ◽  
pp. 539-548 ◽  
Author(s):  
Hugh B. Britten ◽  
Peter F. Brussard

Allozymes were assayed at 20 presumptive loci in increasingly isolated populations of alpine butterflies in the Boloria improba species-group including the endangered Boloria acrocnema. Populations of this Holarctic group were sampled along the Rocky Mountain Cordillera from the Yukon Territory to Colorado. Samples from a more widely distributed and generalist butterfly, Boloria titania, were assayed at 18 presumptive loci for comparative purposes. Estimates of heterozygosity, percent polymorphic loci, mean number of alleles per locus, genetic identity, and distribution of regional and private alleles indicated that the current distribution of butterflies in the B. improba group is the result of a vicariance event. During the last Wisconsin glacial maximum (20 000 to 18 000 years BP) the range of ancestral B. improba was split into Alaskan refugial populations and southern glacial-margin populations. Subsequent dispersal into an ice-free corridor 12 000 to 10 000 years BP from the Alaskan refugial populations gave rise to British Columbia and Alberta B. improba populations. Results from B. titania support these findings.


Genetics ◽  
2003 ◽  
Vol 164 (4) ◽  
pp. 1511-1518 ◽  
Author(s):  
Ning Yu ◽  
Michael I Jensen-Seaman ◽  
Leona Chemnick ◽  
Judith R Kidd ◽  
Amos S Deinard ◽  
...  

Abstract Comparison of the levels of nucleotide diversity in humans and apes may provide much insight into the mechanisms of maintenance of DNA polymorphism and the demographic history of these organisms. In the past, abundant mitochondrial DNA (mtDNA) polymorphism data indicated that nucleotide diversity (π) is more than threefold higher in chimpanzees than in humans. Furthermore, it has recently been claimed, on the basis of limited data, that this is also true for nuclear DNA. In this study we sequenced 50 noncoding, nonrepetitive DNA segments randomly chosen from the nuclear genome in 9 bonobos and 17 chimpanzees. Surprisingly, the π value for bonobos is only 0.078%, even somewhat lower than that (0.088%) for humans for the same 50 segments. The π values are 0.092, 0.130, and 0.082% for East, Central, and West African chimpanzees, respectively, and 0.132% for all chimpanzees. These values are similar to or at most only 1.5 times higher than that for humans. The much larger difference in mtDNA diversity than in nuclear DNA diversity between humans and chimpanzees is puzzling. We speculate that it is due mainly to a reduction in effective population size (Ne) in the human lineage after the human-chimpanzee divergence, because a reduction in Ne has a stronger effect on mtDNA diversity than on nuclear DNA diversity.


2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Hosam M. K. H. El-Gepaly

AbstractSorghum panicles offer a very rich microenvironment for many insect pest species and their natural enemies. Thirty arthropod species belonging to 28 families, pertaining to 9 orders were obtained from sorghum panicles planted in Sohag Governorate, Egypt, during the 3 successive seasons of 2016–2018. Out of these species were 14 pests, 16 predators, and 3 parasitoids. Lepidopteran and hemipteran pests were the most dominant species-infested sorghum-panicles during the mature stages of the panicles. Three microlepidopteran pests, the noctuid, Eublemma (Autoba) gayneri (Roth.); the pyralid, Cryptoblabes gnidiella Millière, and the cosmopterigid, Pyroderces simplex Walsingham, were recorded as major pest species infesting sorghum panicles in Sohag Governorate. The dipteran parasitoid species, Nemorilla floralis (Fallen) (Tachinidae) emerged from the pupae of the E. gayneri and C. gnidiella, while the hymenopteran parasitoid, Brachymeria aegyptiaca (Chalcididae) was obtained from the pupae of all the studied microlepidopteran pests. Spiders, coccinellids, and Orius spp. were the dominant predators collected form panicles. Post-harvest, larvae, and pupae of lepidopteran pests, especially P. simplex recorded (147, 96, and 79 larvae) and (47, 30, and 73 pupae)/10 panicles in 2016, 2017, and 2018 seasons, respectively.


2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Olivia M Gearner ◽  
Marcin J Kamiński ◽  
Kojun Kanda ◽  
Kali Swichtenberg ◽  
Aaron D Smith

Abstract Sepidiini is a speciose tribe of desert-inhabiting darkling beetles, which contains a number of poorly defined taxonomic groups and is in need of revision at all taxonomic levels. In this study, two previously unrecognized lineages were discovered, based on morphological traits, among the extremely speciose genera Psammodes Kirby, 1819 (164 species and subspecies) and Ocnodes Fåhraeus, 1870 (144 species and subspecies), namely the Psammodes spinosus species-group and Ocnodes humeralis species-group. In order to test their phylogenetic placement, a phylogeny of the tribe was reconstructed based on analyses of DNA sequences from six nonoverlapping genetic loci (CAD, wg, COI JP, COI BC, COII, and 28S) using Bayesian and maximum likelihood inference methods. The aforementioned, morphologically defined, species-groups were recovered as distinct and well-supported lineages within Molurina + Phanerotomeina and are interpreted as independent genera, respectively, Tibiocnodes Gearner & Kamiński gen. nov. and Tuberocnodes Gearner & Kamiński gen. nov. A new species, Tuberocnodes synhimboides Gearner & Kamiński sp. nov., is also described. Furthermore, as the recovered phylogenetic placement of Tibiocnodes and Tuberocnodes undermines the monophyly of Molurina and Phanerotomeina, an analysis of the available diagnostic characters for those subtribes is also performed. As a consequence, Phanerotomeina is considered as a synonym of the newly redefined Molurina sens. nov. Finally, spectrograms of vibrations produced by substrate tapping of two Molurina species, Toktokkus vialis (Burchell, 1822) and T. synhimboides, are presented.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weizhao Yang ◽  
Nathalie Feiner ◽  
Catarina Pinho ◽  
Geoffrey M. While ◽  
Antigoni Kaliontzopoulou ◽  
...  

AbstractThe Mediterranean basin is a hotspot of biodiversity, fuelled by climatic oscillation and geological change over the past 20 million years. Wall lizards of the genus Podarcis are among the most abundant, diverse, and conspicuous Mediterranean fauna. Here, we unravel the remarkably entangled evolutionary history of wall lizards by sequencing genomes of 34 major lineages covering 26 species. We demonstrate an early (>11 MYA) separation into two clades centred on the Iberian and Balkan Peninsulas, and two clades of Mediterranean island endemics. Diversification within these clades was pronounced between 6.5–4.0 MYA, a period spanning the Messinian Salinity Crisis, during which the Mediterranean Sea nearly dried up before rapidly refilling. However, genetic exchange between lineages has been a pervasive feature throughout the entire history of wall lizards. This has resulted in a highly reticulated pattern of evolution across the group, characterised by mosaic genomes with major contributions from two or more parental taxa. These hybrid lineages gave rise to several of the extant species that are endemic to Mediterranean islands. The mosaic genomes of island endemics may have promoted their extraordinary adaptability and striking diversity in body size, shape and colouration, which have puzzled biologists for centuries.


Zootaxa ◽  
2017 ◽  
Vol 4272 (4) ◽  
pp. 551
Author(s):  
ROY A. NORTON ◽  
SERGEY G. ERMILOV

Based on the study of type material, other historical specimens, and new collections, the adult of the thelytokous oribatid mite Oribata curva Ewing, 1907 (Galumnidae) is redescribed and the name is recombined to Trichogalumna curva (Ewing, 1907) comb. nov. A confusing history of synonymies and misidentifications is traced in detail, and their effect on published statements about biogeography is assessed. Reliable records of T. curva are only those from North America. The tropical mite Pergalumna ventralis (Willmann, 1932) is not a subspecies of T. curva. The widely-reported Trichogalumna nipponica (Aoki, 1966) and other similar species form a complex with T. curva that needs further morphological and molecular assessment. 


Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 863-872 ◽  
Author(s):  
Helmi Kuittinen ◽  
Montserrat Aguadé

AbstractAn ~1.9-kb region encompassing the CHI gene, which encodes chalcone isomerase, was sequenced in 24 worldwide ecotypes of Arabidopsis thaliana (L.) Heynh. and in 1 ecotype of A. lyrata ssp. petraea. There was no evidence for dimorphism at the CHI region. A minimum of three recombination events was inferred in the history of the sampled ecotypes of the highly selfing A. thaliana. The estimated nucleotide diversity (θTOTAL = 0.004, θSIL = 0.005) was on the lower part of the range of the corresponding estimates for other gene regions. The skewness of the frequency spectrum toward an excess of low-frequency polymorphisms, together with the bell-shaped distribution of pairwise nucleotide differences at CHI, suggests that A. thaliana has recently experienced a rapid population growth. Although this pattern could also be explained by a recent selective sweep at the studied region, results from the other studied loci and from an AFLP survey seem to support the expansion hypothesis. Comparison of silent polymorphism and divergence at the CHI region and at the Adh1 and ChiA revealed in some cases a significant deviation of the direct relationship predicted by the neutral theory, which would be compatible with balancing selection acting at the latter regions.


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