Evolution Commons^™

The First Record Of Upper Permian And Lower Triassic Scorpions From Russia (Chelicerata: Scorpiones), Victor Fet, Dmitry E. Shcherbakov, Michael E. Soleglad

Euscorpius

Several small fragments of fossil scorpions are reported from two localities in Vologda Province, Russia, representing the Upper Permian (Severodvinian, correlated to Wuchiapingian) (Isady) and Lower Triassic just above the Permian-Triassic boundary (Induan) (Nedubrovo). Most observed structures are not diagnostic at genus or family level. The Isady leg fragment possesses ungues (claws), which are both denticulated and setaceous, and resembles a Carboniferous Eobuthus sp. (Eobuthidae). It is the latest record of this type of ungues, which are known in some Paleozoic scorpions (extinct suborder Mesoscorpiones); all extant scorpions have smooth claws without denticulation or setation.

In Situ Infrared Videography Of Sand Scorpion Nighttime Surface Activity, Douglas D. Gaffin

Euscorpius

Sand scorpions make burrows from which they emerge at night to seek mates and prey. Previous ecological studies have documented scorpion activities on the sand surface. Few studies, however, have videotaped scorpion movements in the context of understanding their sensory neurobiology. Our objective is to understand which signals guide scorpions as they emerge from and return to their burrows. Candidate stimuli include chemical trails, footsteps, celestial patterns, geomagnetic cues, humidity and/or temperature gradients, distinctive scents from the burrow, seismic echolocation, memory, or landmark orientation. We videotaped scorpions to learn whether they return to their burrows by the same path they …

Further Considerations On The Species Of The Genus Orthochirus Karsch, 1891 From Africa, With Description Of Three New Species (Scorpiones: Buthidae), Wilson R. Lourenço, Elise-Anne Leguin

Euscorpius

New considerations are proposed regarding the African species of the genus Orthochirus Karsch, 1891. Two species, Orthochirus aristidis (Simon, 1882) and Orthochirus innesi Simon, 1910 have been the subject of several publications in the past decades; however, doubts remain about their exact identity and range of geographical distribution. In this note, their taxonomic status is reinvestigated. The type material is revised and the lectotype and paralectotypes are designated for O. aristidis. Revised diagnoses and illustrations are proposed for both species, and these are confirmed as valid. Three new species are described from Algeria, Morocco, and Mauritania. The total number …

Polymorphism And Hybridization In Species Of Hottentotta Birula, 1908 (Scorpiones: Buthidae), Wilson R. Lourenço, Eric Ythier, Mark Stockmann, John L. Cloudsley-Thompson

Euscorpius

A new and well documented case of hybridization among scorpions is presented. It was obtained under laboratory conditions between Hottentotta jayakari (Pocock) and Hottentotta salei (Vachon) specimens of which had been collected in the northern and southern regions of Oman. Hybrids were successfully produced not only from F₀ males and females, but also from F₁ males and females, thereby attesting to the fact that the first generation obtained (F₁), was completely fertile. Both F₁ and F₂ broods were composed of dark and pale morphs, indicating that the juveniles could inherit either one or …

Redescription Of Tityus Pictus Pocock, 1893 And Tityus Smithii Pocock, 1893, With Notes On The Tityus Species From The Lesser Antilles (Scorpiones: Buthidae), Rolando Teruel

Euscorpius

In the present paper, the taxonomic status of Tityus pictus Pocock, 1893 and all of its junior synonyms is revised. Tityus smithii Pocock, 1893 is restored as a valid species, and the subspecies Tityus smithii microdon Pocock, 1893 (currently T. pictus microdon) is regarded as its junior synonym. Both T. pictus and T. smithii are redescribed, supplementary information on their morphological variability are given, and their geographical distribution is up- dated, including a new locality record for the latter. Also, the taxonomic position and relationships of all Lesser Antillean species of the genus are clarified: it is demonstrated that …

Metabolism And Cryo-Sensitivity Of Domestic Cat (Felis Catus) And Cheetah (Acinonyx Jubatus) Spermatozoa, Kimberly Terrell

LSU New Orleans Theses and Dissertations

Teratospermia (ejaculation of ≥ 60% structurally abnormal spermatozoa) is prevalent among felids facing extinction risk, including the cheetah. This trait also occurs in certain domestic cat populations, providing a valuable research model. Multiple components of sperm function are disrupted in teratospermic cats, and even structurally normal spermatozoa from these ejaculates may be functionally compromised. Teratospermic ejaculates are highly sensitive to damage during cryopreservation, limiting the success of genome resource banking programs for species conservation. Although both teratospermia and cryopreservation are linked to disruptions in multiple energy-dependent sperm processes, the metabolism of these cells has not been investigated. This project explored …

Historical Diversification Of Montane Herpetofauna Within And Between The Sierras Of Mexico, Robert William Bryson Jr.

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mexican highlands consist of four major mountain ranges spanning most of mainland Mexico. The evolutionary history of the Mexican highlands has been shaped by various geological and climatic events over the past several million years. The relative impacts of these historical events on diversification in montane taxa, however, remains uncertain. I used mitochondrial DNA data from three widely distributed species complexes of lizards as a model system to exemplify the potential roles of Neogene mountain formation and Quaternary climate change on timing and tempo of diversification across the Mexican highlands. My results suggested strong geographic partitioning of genetic variation …

A Mathematician Weighs In On The Evolution Debate, Kris H. Green

Journal of Humanistic Mathematics

There are a variety of reasons underlying the lack of public acceptance for the theory of evolution in the United States. An overlooked cause is related to problems with the mathematics curriculum in the K-12 setting. In this essay, we examine this relationship and propose changes to the mathematics curriculum that could improve mathematical thinking while also providing a basis for understanding theories, like evolution, that are poorly understood.

Systematics Of African Skink In The Panaspis Wahlbergi Complex, Ma. Fernanda Medina^, Eli Greenbaum*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …

Biology, Systematics, Phylogenetic Analysis And Dna Character-Based Species Diagnosis Of The False Root-Knot Nematode Nacobbus Aberrans (Thorne, 1935) Thorne & Allen 1944 (Nemata: Pratylenchidae), Angel Ramirez-Suarez

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The False Root-Knot nematode Nacobbus aberrans is a plant parasitic nematode that causes yield losses in several crops and plant protection agencies have established regulations to prevent infestations from spreading to new agricultural areas. The taxonomic status of the nematode has been the subject of controversy due to wide degree of variation exhibited by the species. This variability has led to the suggestion that N. aberrans is actually a species complex rather than a single species. In order to test this hypothesis, we compared twelve N. aberrans populations, which include isolates from western Nebraska, two distinct regions of Mexico and …

Redescription And Taxonomic Position Of Tityus Atriventer Pocock, 1897 (Scorpiones: Buthidae), Rolando Teruel, František Kovařík

Euscorpius

The largely neglected Lesser Antillean scorpion Tityus atriventer Pocock, 1897 is herein redescribed, after study of the two syntypes and one additional adult male. The latter was recently collected from Union Island (about 55 km northeast of Grenada), and it implies the first published finding of this species after its original description, and the first record of the species both outside the type-locality and from the Grenadines islands. The taxonomic position of T. atriventer is clarified (including designation of a lectotype and a paralectotype), its diagnosis is updated, a fully illustrated redescription is presented according to the current taxonomy of …

Evolutionary Patterns In Deep-Sea Mollusks, Elizabeth Ellen Boyle

Graduate Doctoral Dissertations

The evolution of deep-sea fauna is poorly known. We know little about the scales of population differentiation, radiation and colonization of the deep sea. This dissertation explores evolution in the deep sea at the level of population differentiation on ocean-wide scales in a gastropod species Benthonella tenella and phylogeny of a deep-sea subfamily of protobranch bivalves, Ledellinae. While working on the phylogeny of the Ledellinae the presence of mitochondrial heteroplasmy was discovered.

Genetic variation was quantified within and among populations of deep-sea gastropod Benthonella tenella to identify the extent of population differentiation and potential mechanisms that might isolate gene pools. …

A New Species Of Vaejovis From Prescott, Arizona (Scorpiones: Vaejovidae), Richard F. Ayrey, Michael E. Soleglad

Euscorpius

A new scorpion species, Vaejovis crumpi, sp. nov., is described from Prescott, Yavapai Co., Arizona. This species is related to V. paysonensis Soleglad, 1973, and the “sky island” species of southern Arizona. V. crumpi is compared to the seven Vaejovis species currently reported for Arizona, in particular to V. paysonensis.

Relative Abundance Of Mitochondria Rich Cell Types In Threespine Stickleback: Interpopulation Differences And Salinity Effects, Dante Paolino

Honors Scholar Theses

The objective of this study is to determine whether there are evolutionary trade-offs among populations isolated to different salinities in nature with regards to mitochondria rich (MR) cell production. We expected differences among populations in MR cell abundances due to the energy requirements needed to maintain and produce these cells. Eggs from three populations of threespine stickleback (Gasterosteus aculeatus) were hatched and reared for 10 weeks and then the fish were put into one of two salinity challenges: either 0.4 ppt freshwater or 35 ppt saltwater for 13 days. The populations consisted of one isolated to freshwater, one isolated …

Molecular Evolution And Historical Biogeography Of New World Birds, Brian T. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Deciphering the patterns of how biodiversity has evolved across time and space has remained a fundamental objective for biologists for the last 200 years. Researchers are faced with the challenge of interpreting the complexity of evolutionary patterns that have been generated over the deep history of the Earth. The advancement of DNA sequencing technology has yielded a new and powerful genetic toolkit that has allowed biologists to address novel evolutionary questions. For my dissertation research, I used molecular genetics and a statistical framework to study the evolution and historical biogeography of birds distributed in North and South America. My dissertation …

Chimpanzee Vocal Signaling Points To A Multimodal Origin Of Human Language, Jared P. Taglialatela, Jamie L. Russell, Jennifer A. Schaeffer, William D. Hopkins

Faculty Articles

The evolutionary origin of human language and its neurobiological foundations has long been the object of intense scientific debate. Although a number of theories have been proposed, one particularly contentious model suggests that human language evolved from a manual gestural communication system in a common ape-human ancestor. Consistent with a gestural origins theory are data indicating that chimpanzees intentionally and referentially communicate via manual gestures, and the production of manual gestures, in conjunction with vocalizations, activates the chimpanzee Broca’s area homologue – a region in the human brain that is critical for the planning and execution of language. However, it …

Stationary Phase Mutagenesis In Bacillus Subtilisis Independent Of Genome Replication, Mark Upchurch, Holly Martin, Eduardo Robleto

Festival of Communities: UG Symposium (Posters)

Stationary phase mutagenesis is defined as cellular mechanisms that produce genetic diversity in cells experiencing conditions of stress. These processes are associated with many biological phenomena, including those that produce the formation of cancers in animal cells and other degenerative diseases. Also, these mechanisms are associated with the accumulation of beneficial mutations in bacteria, but follow stochastic processes and are controlled by genetic factors. The current models explaining the generation of stress-induced mutations are predicated on the formation of DNA replication intermediates that are formed during the repair of damaged DNA or during DNA replication and transcription encounters. Here we …

Determining The Composition Of The Dwelling Tubes Of Antarctic Pterobranchs, Lukasz J. Sewera

Honors Projects

Pterobranchs are a group of marine invertebrates within the Hemichordata, which share characteristics with both chordates and echinoderms.  Pterobranchs live in colonies of secreted tubes, coenicia, which are composed of a gelatinous material of unknown composition.  Visually, the tubes appear similar to the tunic of tunicates, a group of invertebrates within the Chordata. The nonproteinaceous tunic of tunicates is composed of cellulose, which is unusual.  The goal of this study was to determine the composition of the pterobranch coenicium. Some aspects of pterobranch phylogeny are still unclear even after multiple molecular and morphological studies.  Identification of any new shared characteristics …

The Genus Butheoloides Hirst, 1925 (Scorpiones, Buthidae) In Morocco, With A Description Of А New Species, Wilson R. Lourenço, Oulaid Touloun, Ali Ali Boumezzough

Euscorpius

A new species belonging to the genus Butheoloides Hirst, 1925 (subgenus Butheoloides Hirst, 1925) (Scorpiones, Buthidae) is described from two localities in Morocco: north of Sidi Ifni in the southern coast and Sidi Moussa west of Tiznit. With the description of Butheoloides (Butheoloides) littoralis sp. n., the total number of species of this genus known from Morocco is raised to five. This makes Morocco the region in Africa with the highest diversity for Butheoloides species.