%{search_type} search results

1,423 catalog results

RSS feed for this result
View results as:
Number of results to display per page
Book
1 online resource.
Book
1 online resource.
  • Cover; Challenging the Modern Synthesis; Copyright; Contents; Contributors; Introduction: Challenging the Modern Synthesis; Part I: Adaptation and Selection; 1. Natural Selection, Adaptation, and the Recovery of Development; 2. Why Would We Call for a New Evolutionary Synthesis? The Variation Issue and the Explanatory Alternatives; 3. Genetic Assimilation and the Paradox of Blind Variation; 4. Evolutionary Theory Evolving; Part II: Development; 5. Evo-​Devo and the Structure(s) of Evolutionary Theory: A Different Kind of Challenge; 6. Toward a Nonidealist Evolutionary Synthesis
  • 7. Evolvability and Its Evolvability8. "Chance Caught on the Wing": Metaphysical Commitment or Methodological Artifact?; Part III: Inheritance; 9. Limited Extended Inheritance; 10. Heredity and Evolutionary Theory; 11. Serial Homology as a Challenge to Evolutionary Theory: The Repeated Parts of Organisms from Idealistic Morphology to Evo-​Devo; Index
Since its origin in the early 20th century, the Modern Synthesis theory of evolution has grown to become the orthodox view on the process of organic evolution. Its central defining feature is the prominence it accords to genes in the explanation of evolutionary dynamics. Since the advent of the 21st century, however, the Modern Synthesis has been subject to repeated and sustained challenges. These are largely empirically driven. In the last two decades, evolutionary biology has witnessed unprecedented growth in the understanding of those processes that underwrite the development of organisms and the inheritance of characters. The empirical advances usher in challenges to the conceptual foundations of evolutionary theory. The extent to which the new biology challenges the Modern Synthesis has been the subject of lively debate. Many current commentators charge that the new biology of the 21st century calls for a revision, extension, or wholesale rejection of the Modern Synthesis Theory of evolution. Defenders of the Modern Synthesis maintain that the theory can accommodate the exciting new advances in biology. The original essays collected in this volume survey the various challenges to the Modern Synthesis arising from the new biology of the 21st century. The authors are evolutionary biologists, philosophers of science, and historians of biology from Europe and North America. Each of the essays discusses a particular challenge to the Modern Synthesis treatment of inheritance, development, or adaptation. Taken together, the essays cover a spectrum of views, from those that contend that the Modern Synthesis can rise to the challenges of the new biology, with little or no revision required, to those that call for the abandonment of the Modern Synthesis. The collection will be of interest to researchers and students in evolutionary biology, and the philosophy and history of the biological sciences.
(source: Nielsen Book Data)9780199377176 20171017
ProQuest Ebook Central Access limited to 1 user
Book
1 online resource (15 p.) : digital, PDF file.
This project has demonstrated the level of commercial readiness for production of the industrial chemical, 1,4-butanediol (BDO), from lignocellulosic biomass by engineered E. coli. Targets were BDO titer, rate, and yield (TRY) and growth in lignocellulosic hydrolysates (Hz). A range of Hzs were used to assess limitations for biomass-to-BDO. Via adaptive evolution methods, whole-genome sequencing, and introduction of identified target genes, strains co-utilizing C5/ C6 sugars were made. The composition of Hz versus TRY led to a modified Hz composition. This was used in partnership with the DOE to redirect the project to focus on 1) several biomass Hz from new suppliers, 2) Hz specification due to the characteristics of the Genomatica BDO process, 3) a gene cassette to engineer any BDO producing strain for biomass, and 4) modified BDO recovery to more economically recover BDO at industry specifications. BDO TRY and growth of the E. coli strains were predictable based on Hz composition from several suppliers. This defined metrics for biomass Hz composition to achieve BDO TRY along with internal TEA to evaluate the economic potential of each modification to strain, Hz feed, and process. An improved biomass-to-BDO production strain reached BDO T-R in a 30 L fermentation above original objectives. Yield approached the proposed Y and modifications to BDO recovery were demonstrated. Genomatica is now in the position of being able to incorporate biomass feedstocks into the commercial GENO BDO process.
Book
1 online resource (452 p.) : ill. (some col.).
"Optimization plays a key role in the design, planning and operation of chemical and related processes for several decades. Techniques for solving optimization problems are of deterministic or stochastic type. Of these, stochastic techniques can solve any type of optimization problems and can be adapted for multiple objectives. Differential evolution (DE), proposed about two decades ago, is one of the stochastic techniques. Its algorithm is simple to understand and use. DE has found many applications in chemical engineering. This unique compendium focuses on DE, its recent developments and applications in chemical engineering. It will cover both single and multi-objective optimization. The book contains a number of chapters from experienced editors, and also several chapters from active researchers in this area."--Publisher's website.
Book
1 online resource.
EBSCOhost Access limited to 1 user
Book
1 online resource.
EBSCOhost Access limited to 1 user
Book
1 online resource ( xxiii, 333 pages) :
  • Forward Part I: History of Attitudes toward Evolution in the South 1. Darwinism in the American South 2. Race and Evolution in Antebellum Alabama: The Polygenist Prehistory We'd Rather Ignore 3. "The Cadillac of Disclaimers": Twenty Years of Official Antievolution in Alabama4. Deconstructing the Alabama Disclaimer with Students: A Powerful Lesson in Evolution, Politics, and Persuasion Part II: Culture and Education in the American South 5. Evolution Acceptance among Preservice Science Teachers in the South6. Evolution Acceptance among Undergraduates in the South 7. Religion, Politics, and Science for U.S. Southerners 8. Sharing News and Views about Evolution in Social Media Part III: Perspectives and Resources from the Natural Sciences 9. Resources for Teaching Biological Evolution in the Deep South 10. Teaching Louisiana Students about Evolution by Comparing the Anatomy of Fishes and Humans 11. Teaching Evolution in Real Time 12. Trace Fossils of Alabama: Life in the Coal Age Part IV: Perspectives and Resources from the Social Sciences 13. What Can the Alabama Mississippians Teach Us about Human Evolution and Behavior?14. Tattooing Commitment, Quality, and Football in Southeastern North America APPENDIX: Additional Resources for Biological Evolution Education in Alabama Afterward.
  • (source: Nielsen Book Data)9781349951383 20170502
This volume reaches beyond the controversy surrounding the teaching and learning of evolution in the United States, specifically in regard to the culture, politics, and beliefs found in the Southeast. The editors argue that despite a deep history of conflict in the region surrounding evolution, there is a wealth of evolution research taking place-from biodiversity in species to cultural evolution and human development. In fact, scientists, educators, and researchers from around the United States have found their niche in the South, where biodiversity is high, culture runs deep, and the pace is just a little bit slower.
(source: Nielsen Book Data)9781349951383 20170502
EBSCOhost Access limited to 1 user
Book
1 online resource.
  • Evolution in the dark - introduction.- The role of rudimentation in evolution.- Diversity and phylogenetic age of cave species.- Surface and cave populations of Mexican Astyanax.- Complexity of interrelationship of cave and surface fish.- Regressive and constructive traits in Astyanax surface and cave fish.- Mechanisms of regressive evolution.
  • (source: Nielsen Book Data)9783662545102 20170731
This book provides fascinating insights into the development and genetics of evolutionary processes on the basis of animals living in the dark, such as the Astyanax cave fish. Biologically functionless traits show high variability, which results from neutral deleterious mutations no longer being eliminated by natural selection, which normally acts to preserve functional capability. These negative mutations accumulate until the traits they are responsible for become rudimentary or even lost. The random genetic basis of regressive evolution is in accordance with Nei's Neutral Theory of Molecular Evolution, which applies to the molecular level. Such processes are particularly conspicuous in species living in constant darkness, where, for example in Astyanax, all traits depending on the exposure to light, like eyes, pigmentation, visually triggered aggressive behaviour, negative phototaxis, and several peripheral outcomes of circadian rhythmicity, are useless and diminish. In compensation constructive traits like taste, olfaction or the lateral line senses are improved by selection and do not show variability. Regressive and constructive traits inherit independently, proving that the rudimentation process is not driven by pleiotropic linkage between them. All these traits are subject to mosaic evolution and exhibit unproportional epistatic gene effects, which play an important role in evolutionary adaptation and improvement. Offering valuable evolutionary insights and supplemented by a wealth of illustrations, this book will appeal to evolutionary and developmental biologists alike.
(source: Nielsen Book Data)9783662545102 20170731
EBSCOhost Access limited to 1 user
Video
1 online resource (1 streaming video file (34 min.) : color, sound).
  • Contents: History of discovery of The complement system
  • Evolution of complement
  • The alternative complement pathway
  • Defects and diseases associated with complement
  • Complement and inflammation.
Book
1 online resource.
  • Part I: Self/Nonself Evolution, â A new view of how MHC class I molecules fight disease: generalists and specialists.- Evolution and diversity of defensins in vertebrates.- Interdependencies between the adaptation and interference modules guide efficient CRISPR-Cas immunity.- How the other half lives: CRISPR-Cas's influence on bacteriophages.- Hidden Silent Codes in Viral Genomes.- Self and Non-Self from a Genomic Perspective: Transposable Elements.- Mammalian-specific traits generated by LTR retrotransposon-derived SIRH genes.- Part II: Species Evolution and Evolution of Complex Traits, The life history of domesticated genes illuminates the evolution of novel mammalian genes.- Evolution of Complex Traits in Human Populations.- The descent of bison.- Convergent and parallel evolution in early Glires (Mammalia).- Reductive evolution of apicomplexan parasites from phototrophic an-cestors.- Part III : Methods and Concepts, Evolution of milk oligosaccharides and their function in monotremes and marsupials.- Mechanistic Models of Protein Evolution.- Genome-wide screens for molecular convergent evolution in mammals.- Assessing evolutionary potential in tree species through ecology-informed genome screening.- Evolutionary constraints on coding sequences at the nucleotidic level: a statistical physics approach.- Case studies of seven gene families with unusual high retention rate since the Vertebrate and Teleost Whole Genome Duplications.
  • (source: Nielsen Book Data)9783319615684 20171009
This book presents 19 selected contributions to the 20th Evolutionary Biology Meeting in Marseille, which took place in September 2016. They are grouped under the following major themes:* Self/Nonself Evolution* Species Evolution and Evolution of Complex Traits* Methods and Concepts The aims of the annual meetings in Marseille - which bring together leading evolutionary biologists and other scientists using evolutionary biology concepts, e.g. for medical research - are to promote the exchange of ideas and to encourage interdisciplinary collaborations. Offering a revealing overview of the latest findings in the field of evolutionary biology, this book represents an invaluable source of information for scientists, teachers and advanced students alike.
(source: Nielsen Book Data)9783319615684 20171009
Video
1 online resource (1 streaming video file (44 min.) : color, sound).
  • Contents: Human evolutionary history
  • Human evolution and childbirth
  • Birth in other primates
  • How anatomical changes for bipedalism impact birth
  • Birth in early human ancestors
  • The helpless human newborn
  • The evolutionary legacy of birth
  • Why women benefit from assistance at birth
  • Value of emotional support during labor and delivery.
Book
1 online resource (18 p.) : digital, PDF file.
The genome of Caldithrix abyssi, the first cultivated representative of a phylum-level bacterial lineage, was sequenced within the framework of Genomic Encyclopedia of Bacteria and Archaea (GEBA) project. The genomic analysis revealed mechanisms allowing this anaerobic bacterium to ferment peptides or to implement nitrate reduction with acetate or molecular hydrogen as electron donors. The genome encoded five different [NiFe]- and [FeFe]-hydrogenases, one of which, group 1 [NiFe]-hydrogenase, is presumably involved in lithoheterotrophic growth, three other produce H<sub>2</sub> during fermentation, and one is apparently bidirectional. The ability to reduce nitrate is determined by a nitrate reductase of the Nap family, while nitrite reduction to ammonia is presumably catalyzed by an octaheme cytochrome c nitrite reductase εHao. The genome contained genes of respiratory polysulfide/thiosulfate reductase, however, elemental sulfur and thiosulfate were not used as the electron acceptors for anaerobic respiration with acetate or H<sub>2</sub>, probably due to the lack of the gene of the maturation protein. Nevertheless, elemental sulfur and thiosulfate stimulated growth on fermentable substrates (peptides), being reduced to sulfide, most probably through the action of the cytoplasmic sulfide dehydrogenase and/or NAD(P)-dependent [NiFe]-hydrogenase (sulfhydrogenase) encoded by the genome. Surprisingly, the genome of this anaerobic microorganism encoded all genes for cytochrome c oxidase, however, its maturation machinery seems to be non-operational due to genomic rearrangements of supplementary genes. Despite the fact that sugars were not among the substrates reported when C. abyssi was first described, our genomic analysis revealed multiple genes of glycoside hydrolases, and some of them were predicted to be secreted. This finding aided in bringing out four carbohydrates that supported the growth of C. abyssi: starch, cellobiose, glucomannan and xyloglucan. The genomic analysis demonstrated the ability of C. abyssi to synthesize nucleotides and most amino acids and vitamins. Finally, the genomic sequence allowed us to perform a phylogenomic analysis, based on 38 protein sequences, which confirmed the deep branching of this lineage and justified the proposal of a novel phylum Calditrichaeota.
Video
1 online resource (1 streaming video file (44 min.) : color, sound).
  • Contents: Enamel biology
  • Enamel structure & morphology
  • Enamel microanatomy
  • Enamel decussation & fractures
  • Enamel mechanical properties
  • Environmental background & human evolution
  • Tooth size, bite forces & enamel integrity.
Video
1 online resource (1 streaming video file (19 min.) : color, sound).
  • Contents: Bone biology
  • Bone structure
  • Collagen fiber orientation
  • Aging & fractures
  • Osteocyte density.
Video
1 online resource (1 streaming video file (45 min.) : color, sound).
  • Contents: Aging (senescence) our evolved life history
  • Global maximum life expectancy
  • Postmenopausal survival characterizes all human populations
  • Longevity affects age at maturity across our primate order
  • Comparing humans and chimpanzees
  • Grandmother effects and the evolution of human life history
  • What physiological mechanisms have slowed human aging?
  • Age-specific fertility rates in humans & chimpanzees
  • Overall mortality effects on age-specific variation.
Book
1 online resource (p. 1723-1738) : digital, PDF file.
The MALAT1 (Metastasis-Associated Lung Adenocarcinoma Transcript 1) gene encodes a noncoding RNA that is processed into a long nuclear retained transcript (MALAT1) and a small cytoplasmic tRNA-like transcript (mascRNA). Using an RNA sequence- and structure-based covariance model, we identified more than 130 genomic loci in vertebrate genomes containing the MALAT1 3' end triple-helix structure and its immediate downstream tRNA-like structure, including 44 in the green lizard Anolis carolinensis. Structural and computational analyses revealed a co-occurrence of components of the 3' end module. MALAT1-like genes in Anolis carolinensis are highly expressed in adult testis, thus we named them testis-abundant long noncoding RNAs (tancRNAs). MALAT1-like loci also produce multiple small RNA species, including PIWI-interacting RNAs (piRNAs), from the antisense strand. The 3' ends of tancRNAs serve as potential targets for the PIWI-piRNA complex. Furthermore, we have identified an evolutionarily conserved class of long noncoding RNAs (lncRNAs) with similar structural constraints, post-transcriptional processing, and subcellular localization and a distinct function in spermatocytes.
Book
1 online resource (Article No. e1005316) : digital, PDF file.
Phylogenetic inference is an attractive means to reconstruct transmission histories and epidemics. However, there is not a perfect correspondence between transmission history and virus phylogeny. Both node height and topological differences may occur, depending on the interaction between within-host evolutionary dynamics and between-host transmission patterns. To investigate these interactions, we added a within-host evolutionary model in epidemiological simulations and examined if the resulting phylogeny could recover different types of contact networks. To further improve realism, we also introduced patient-specific differences in infectivity across disease stages, and on the epidemic level we considered incomplete sampling and the age of the epidemic. Second, we implemented an inference method based on approximate Bayesian computation (ABC) to discriminate among three well-studied network models and jointly estimate both network parameters and key epidemiological quantities such as the infection rate. Our ABC framework used both topological and distance-based tree statistics for comparison between simulated and observed trees. Overall, our simulations showed that a virus time-scaled phylogeny (genealogy) may be substantially different from the between-host transmission tree. This has important implications for the interpretation of what a phylogeny reveals about the underlying epidemic contact network. In particular, we found that while the within-host evolutionary process obscures the transmission tree, the diversification process and infectivity dynamics also add discriminatory power to differentiate between different types of contact networks. We also found that the possibility to differentiate contact networks depends on how far an epidemic has progressed, where distance-based tree statistics have more power early in an epidemic. Finally, we applied our ABC inference on two different outbreaks from the Swedish HIV-1 epidemic.
Book
1 online resource ( xiii, 380 pages) :
  • Preface xi Chapter 1 Genes: How they are inherited 1 Blood and ABO blood groups 1 Inheritance of ABO blood groups 3 Inheritance of more than one gene: ABO and rhesus blood groups 4 Sex chromosomes 9 Determining how traits are inherited: Pedigree analysis 10 What is and isn t inherited 12 Concluding remarks 14 Chapter 2 What genes are, what they do, and how they do it 15 Chromosomes, proteins, and nucleic acids: Figuring out what genes are 15 The structure of genes and what they do: The central dogma and the flow of information 18 How genes do what they do: Transcription and translation 19 The genetic code 22 DNA replication 23 The consequences of mutations 23 What causes mutations? 25 A final cautionary note 26 Chapter 3 Genes in populations 27 What is a population? 27 The concept of effective population size 28 The sex ratio and Ne 29 Inbreeding and Ne 30 Variation in population size over time and Ne 30 Differential fertility and Ne 31 Ne for humans 33 Chapter 4 A simple model: Hardy Weinberg equilibrium 35 The gene pool with no evolution: The Hardy Weinberg principle 35 Exceptions 38 A real-life example 39 Some practical uses for Hardy Weinberg 41 Chapter 5 Evolutionary forces 45 Non random mating 45 Small population size 48 Mutation 53 Migration 56 Selection 60 Evolutionary forces: Summary 68 Chapter 6 Molecular evolution 69 Functionally less important molecules (or parts of molecules) evolve faster than more important ones 70 Conservative substitutions occur more frequently than disruptive ones 71 The rate of molecular evolution is approximately constant 72 Contrasting phenotypic and molecular evolution 73 How do new gene functions arise? 74 Gene regulation and phenotypic evolution 77 Chapter 7 Genetic markers 79 Classical markers: Immunogenetic markers 79 Classical markers: Biochemical polymorphisms 81 The first DNA markers: Restriction fragment length polymorphisms 84 Polymerase chain reaction 86 DNA sequencing: The sanger method 89 Next-generation sequencing 90 Targeting single DNA bases: SNPs 92 Variation in length 94 Other structural variation 99 Concluding remarks 100 Chapter 8 Sampling populations and individuals 103 Sampling populations: General issues 103 Sampling populations: Ethical issues 105 Archival samples 108 Chapter 9 Sampling DNA regions 111 Mitochondrial DNA 111 Y chromosomal DNA 116 Autosomal DNA 119 X chromosome DNA 121 Public databases 122 Chapter 10 Analysis of genetic data from populations 125 Genetic diversity within populations 125 Genetic distances between populations 128 Displaying genetic distance data: Trees 135 Displaying genetic data: Multidimensional scaling, principal components, and correspondence analysis 139 Chapter 11 Analysis of genetic data from individuals 147 Genetic distances for DNA sequences 147 Trees for DNA sequences 153 Rooting trees 156 Assessing the confidence of a tree 157 Network analyses 160 Genome-wide data: Unsupervised analyses 161 Chapter 12 Inferences about demographic history 175 Dating events 175 Population size and population size change 187 Migration and admixture 194 Putting it all together 197 Chapter 13 Our closest living relatives 201 Resolving the trichotomy 205 Complications 206 Ape genetics and genomics 208 Chapter 14 The origins of our species 211 Human origins: The fossil record 215 Models for human origins 218 The genetic evidence: mtDNA 222 The genetic evidence: Y chromosome 224 The genetic evidence: Autosomes 225 Chapter 15 Ancient DNA 229 Properties of ancient DNA: Degradation 229 Properties of ancient DNA: Damage 229 Properties of ancient DNA: Contamination 232 History of ancient DNA studies 236 Ancient DNA: Archaic humans 237 Other uses for ancient DNA 244 Chapter 16 Dispersal and migration 247 Out of Africa how many times, when, and which way did they go? 251 Into remote lands: The colonization of the Americas 259 Into even more remote lands: The colonization of Polynesia 267 Some concluding remarks 281 Chapter 17 Species-wide selection 283 Species-wide selection 284 Nonsynonymous mutations and the dN/dS ratio 284 Tests based on the allele frequency distribution 288 Selection tests based on comparing divergence to polymorphism 293 Archaic genomes 297 Chapter 18 Local selection 299 Example: Lactase persistence 304 Example: EDAR 309 Ancient DNA 318 Concluding remarks 318 Chapter 19 Genes and culture 321 Are humans still evolving? 321 Genetic variation can be directly influenced by cultural practices 322 Genetic variation can be indirectly influenced by cultural practices 322 Using genetic analyses to learn more about cultural practices: Agricultural expansions 326 Using genetic analyses to learn more about cultural practices: Language replacements 332 Using genetic analyses to learn more about cultural practices: Dating the origin of clothing 333 Concluding remarks 339 Chapter 20 Ongoing and future developments in molecular anthropology 341 More and different kinds of data: The other omics 341 Beyond you : The microbiome 344 More analyses 347 Relating phenotypes to genotypes 351 Personal ancestry testing and genomics 360 References 363 Suggestions for additional reading 373 Index 375.
  • (source: Nielsen Book Data)9781118061626 20170502
Molecular anthropology uses molecular genetic methods to address questions and issues of anthropological interest. More specifically, molecular anthropology is concerned with genetic evidence concerning human origins, migrations, and population relationships, including related topics such as the role of recent natural selection in human population differentiation, or the impact of particular social systems on patterns of human genetic variation. Organized into three major sections, An Introduction to Molecular Anthropology first covers the basics of genetics what genes are, what they do, and how they do it as well as how genes behave in populations and how evolution influences them. The following section provides an overview of the different kinds of genetic variation in humans, and how this variation is analyzed and used to make evolutionary inferences. The third section concludes with a presentation of the current state of genetic evidence for human origins, the spread of humans around the world, the role of selection and adaptation in human evolution, and the impact of culture on human genetic variation. A final, concluding chapter discusses various aspects of molecular anthropology in the genomics era, including personal ancestry testing and personal genomics. An Introduction to Molecular Anthropology is an invaluable resource for students studying human evolution, biological anthropology, or molecular anthropology, as well as a reference for anthropologists and anyone else interested in the genetic history of humans.
(source: Nielsen Book Data)9781118061626 20170502
EBSCOhost Access limited to 3 simultaneous users
Book
1 online resource.
  • I. From stars to embryos: Galaxy gazing
  • Handy humans and other protopeople
  • A human with no nerves
  • II. Cycles of life: From celestial furnaces
  • Life cycles: animals versus stars
  • The moment of conception
  • III. In the beginning: A universe begins
  • The opposite of a whimper
  • Our internal evolution
  • IV. Structures and functions: Spacious heavens
  • The ecological theater
  • Becoming an adult
  • V. From boulders to brains: Rubble around the sun
  • The very first animals
  • Here comes the brain
  • VI. Milestones of discovery: Exoplanets and aliens
  • From Darwin to Darwinism
  • Analyzing the embryo
  • VII. Endings and enlightenment: The end of the world
  • Extinction and how to avoid it
  • From embryo to enlightenment.
Book
1 online resource (Article No. 39) : digital, PDF file.
While the catalytic activity of some Ru-based polypyridine complexes in water oxidation is well established, the relationship between their chemical structure and activity is less known. In this work, the single site Ru complex [Ru(bpy)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</sup> (bpy = 2,20-bipyridine)—which can exist as either a cis isomer or a trans isomer—is investigated. While a difference in the catalytic activity of these two isomers is well established, with cis-[Ru(bpy)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</su p> being much more active, no mechanistic explanation of this fact has been presented. The oxygen evolving capability of both isomers at multiple concentrations has been investigated, with cis-[Ru(bpy)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</su p> showing a second-order dependence of O2 evolution activity with increased catalyst concentration. Measurement of the electron paramagnetic resonance (EPR) spectrum of cis-[Ru(bpy)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</su p>, shortly after oxidation with CeIV, showed the presence of a signal matching that of cis, cis-[Ru<sup>III</sup>(bpy)<sub>2</sub>(H<sub>2</sub>O)ORu<sup>IV </sup>(bpy)<sub>2</sub>(OH)]<sup>4+</sup>, also known as “blue dimer”. The formation of dimers is a concentration-dependent process, which could serve to explain the greater than first order increase in catalytic activity. The trans isomer showed a first-order dependence of O<sub>2</sub> evolution on catalyst concentration. As a result, behavior of [Ru(bpy)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</sup> isomers is compared with other Ru-based catalysts, in particular [Ru(tpy)(bpy)(H<sub>2</sub>O)]<sup>2+</sup> (tpy = 2,20; 6,20 0-terpyridine).