Evolution Commons^™

The Complexity-Independence Of The Origin Of Life, Radu Popa

Systems Science Friday Noon Seminar Series

It is often stated that the macroevolution of life is driven toward increased Complexity, and indeed, biosystems situated at higher evolutionary level show higher levels of Complexity. Yet, evidence also shows that some dynamic systems evolve toward lower entropy states, and not by increasing Complexity, but by increasing Organization. Organization is a parameter with two almost orthogonal components: Order and Complexity. Hence, it is possible for a dynamic system to experience changes in Organization in ways that do not elicit changes in Complexity. Whether Order or Complexity controls changes in Organization is dictated by the capacity of a system to …

It's Not Too Late For The Harpy Eagle (Harpia Harpyja): High Levels Of Genetic Diversity And Differentiation Can Fuel Conservation Programs, Heather R. Lerner, Jeff A. Johnson, Alec R. Lindsay Ph. D., Lloyd F. Kiff, David P. Mindell

Faculty Works

Background: The harpy eagle (Harpia harpyja) is the largest Neotropical bird of prey and is threatened by human persecution and habitat loss and fragmentation. Current conservation strategies include local education, captive rearing and reintroduction, and protection or creation of trans-national habitat blocks and corridors. Baseline genetic data prior to reintroduction of captive-bred stock is essential for guiding such efforts but has not been gathered previously.

Methodology/Findings: We assessed levels of genetic diversity, population structure and demographic history for harpy eagles using samples collected throughout a large portion of their geographic distribution in Central America (n = 32) and South America …

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …

Introduction And Spread Of Bromus Tectorum (Cheatgrass) Into Midwestern United States: Population Genetic And Evolutionary Consequences, Temsha D. Huttanus

Boise State University Theses and Dissertations

High propagule pressure is correlated with invasion success, and has important implications for the genetic diversity and evolutionary potential of a species in its introduced range. Here, I examine an invasive annual grass Bromus tectorum and document the population genetic consequences that resulted from multiple introductions of genotypes native to different Eurasian regions into the North American Midwest. Herbarium collections showed that B. tectorum was first recorded near-contemporaneously throughout the Midwest in the late 1800s. Allozyme diversity data from 60 populations were used to assess the origin and frequency of introductions into the Midwest. Genetic variation and structure was compared …

Phylogenetic Analyses Reveal Monophyletic Origin Of The Ergot Alkaloid Gene Dmaw In Fungi, Miao Liu, Daniel G. Panaccione, Christopher L. Schardl

Plant Pathology Faculty Publications

Ergot alkaloids are indole-derived mycotoxins that are important in agriculture and medicine. Ergot alkaloids are produced by a few representatives of two distantly related fungal lineages, the Clavicipitaceae and the Trichocomaceae. Comparison of the ergot alkaloid gene clusters from these two lineages revealed differences in the relative positions and orientations of several genes. The question arose: is ergot alkaloid biosynthetic capability from a common origin? We used a molecular phylogenetic approach to gain insights into the evolution of ergot alkaloid biosynthesis. The 4-γ,γ-dimethylallyltryptophan synthase gene, dmaW, encodes the first step in the pathway. Amino acid sequences deduced …

Alternative Life Cycle Strategies And Colonization Of Young Anurans By Gorgoderina Attenuata In Nebraska, Matthew G. Bolek, Scott D. Snyder, John J. Janovy Jr.

Biology Faculty Publications

Studies on life cycles and epizootiology of North American frog bladder flukes indicate that adult frogs become infected predominantly by ingesting tadpoles or other frogs that serve as second intermediate hosts for gorgoderid metacercariae. Other studies have indicated that newly metamorphosed frogs are rarely infected with these parasites because they are gape-limited predators that cannot feed on large intermediate hosts such as tadpoles and other frogs. We examined the role of potential intermediate hosts in the recruitment of the frog bladder fluke, Gorgoderina attenuata, to metamorphosed northern leopard frogs, Woodhouse’s toads, and bullfrogs from western Nebraska. We completed the …

Ambystoma Maculatum (Spotted Salamander) Occurrence, Kristine L. Grayson, A. M. Bloch

Biology Faculty Publications

Natural History Notes: Ambystoma maculatum is a wide ranging mole salamander found from Nova Scotia and southern Ontario through Georgia and eastern Texas (Conant and Collins 1998).

Parallel Shifts In Ecology And Natural Selection In An Island Lizard, Ryan Calsbeek, Wolfgang Buermann, Thomas B. Smith

Dartmouth Scholarship

Natural selection is a potent evolutionary force that shapes phenotypic variation to match ecological conditions. However, we know little about the year-to-year consistency of selection, or how inter-annual variation in ecology shapes adaptive landscapes and ultimately adaptive radiations. Here we combine remote sensing data, field experiments, and a four-year study of natural selection to show that changes in vegetation structure associated with a severe drought altered both habitat use and natural selection in the brown anole, Anolis sagrei.

Results: In natural populations, lizards increased their use of vegetation in wet years and this was correlated with selection on limb length …

What's In A Word? On Reading--And Misreading--Alfred Russel Wallace, Charles H. Smith

DLPS Faculty Publications

No abstract provided.

A Study Of The Morphology Of Tatenectes Laramiensis, A Cryptocleidoid Plesiosaur From The Sundance Formation (Wyoming, Usa), Hallie P. Street

Theses, Dissertations and Capstones

Tatenectes laramiensis is a cryptocleidoid plesiosaur from the Late Jurassic Sundance Formation. This study primarily concerns a partial skeleton comprised of dorsal vertebrae, ribs, gastralia, and pelvic girdle. Even though the skeleton is incomplete, it is hypothesized that the preserved fossils are sufficient to indicate the overall body shape and also the preferred habitat of Tatenectes. Possibly the most notable of the novel characters is the pachyostotic state of the gastralia. In relation to the ribs and overall size of Tatenectes, in comparison to the gastralia in related taxa, these gastralia are disproportionately robust. The combination of these morphologies suggests …

On The Monkeys Of The Amazon (1852), Alfred Russel Wallace

Alfred Russel Wallace Classic Writings

No abstract provided.

On The Law Which Has Regulated The Introduction Of New Species (1855), Alfred Russel Wallace

Alfred Russel Wallace Classic Writings

No abstract provided.

On The Tendency Of Varieties To Depart Indefinitely From The Original Type (1858), Alfred Russel Wallace

Alfred Russel Wallace Classic Writings

No abstract provided.

Molecular Evolution Of Genes Underlying Phenotypic Differences Between Humans And Chimpanzees, Santhoshi Bandla

Legacy Theses & Dissertations (2009 - 2024)

Chimpanzees (Pan troglodytes) and bonobos (P. paniscus) are often used as models to study the genetic and morphological changes on the lineage leading to the modern humans (Homo sapiens). Results of this dissertation suggest that, in comparison to other hominoids, chimpanzees and bonobos are more derived in their relative testes sizes and promiscuous mating systems. Phylogenetic analysis of genes that might underlie increased testes size revealed that, in addition to being a sex-determining gene, SRY displays Pan-specific amino acid replacements that make it a compelling candidate as a testes-size determining gene. Strikingly, SRY and another candidate gene, DMRT3, display patterns …

Primate Phylogenomics: Developing Numerous Nuclear Non-Coding, Non-Repetitive Markers For Ecological And Phylogenetic Applications And Analysis Of Evolutionary Rate Variation, Zuogang Peng, Navin Elango, Derek E. Wildman, Soojin V. Yi

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Genetic analyses are often limited by the availability of appropriate molecular markers. Markers from neutrally evolving genomic regions may be particularly useful for inferring evolutionary histories because they escape the constraints of natural selection. For the majority of taxa however, obtaining such markers is challenging. Advances in genomics have the potential to alleviate the shortage of neutral markers. Here we present a method to develop numerous markers from putatively neutral regions of primate genomes.

Results

We began with the available whole genome sequences of human, chimpanzee and macaque. Using computational methods, we identified a total of 280 potential …

Molecular Systematics And Phylogeography Of The Genus Richardsonius, Derek Dee Houston

UNLV Theses, Dissertations, Professional Papers, and Capstones

The complex geological and climatic events that significantly altered the landscape throughout the Cenozoic Era impacted the diversification of many North American taxa, including freshwater fishes. Here, I employ an array of phylogenetic analyses using a multiple gene tree approach to address several questions regarding the phylogenetic relationships of the North American cyprinid genus Richardsonius and two other closely related genera, Clinostomus and Iotichthys. I also use divergence time estimates generated using fossil calibrations to qualitatively assess the phylogeographic implications of evolution within and among these three genera. Mitochondrial and nuclear DNA sequences show a sister relationship between Iotichthys and …

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Ecology And Molecular Phylogenetics Of Hydnora (Hydnoraceae) In Southern Africa, Jay Francis Bolin

Biological Sciences Theses & Dissertations

The Hydnoraceae are a clade of root holoparasitic angiosperms that contain two small genera, Hydnora and Prosopanche. This study, focused on Hydnora, presents novel data regarding the pollination biology, germination ecology, parasite-host nutritional relationships, and the molecular systematics of this group. Experimental addition of the primary pollinator, Dermestes maculatus to Hydnora africana chamber flowers demonstrated beetle imprisonment during the carpellate stage. Changes in the inner surfaces of the androecial chamber allowed beetle escape after pollen release. Most beetles escaped, dusted with viable pollen, three days after pollen release. To investigate germination ecology, aqueous root extracts of host and …