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Extraordinary Diversity (extraordinary + diversity)
Selected AbstractsExtraordinary diversity in vasopressin (V1a) receptor distributions among wild prairie voles (Microtus ochrogaster): Patterns of variation and covariationTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 4 2003Steven M. Phelps Abstract The vasopressin V1a receptor is a gene known to be central to species differences in social behavior, including differences between the monogamous prairie vole and its promiscuous congeners. To examine how individual differences compare with species differences, we characterize variability in the expression of the vasopressin V1a receptor (V1aR) in a large sample of wild prairie voles. We find a surprising degree of intraspecific variation in V1aR binding that does not seem attributable to experimental sources. Most brain regions exhibit differences between upper and lower quartiles that are comparable to differences between species in this genus. Regions that are less variable have been implicated previously in regulating monogamous behaviors, suggesting that the lack of variation at these sites could reflect natural selection on mating system. Many brain regions covary strongly. The overall pattern of covariation reflects the developmental origins of brain regions. This finding suggests that shared mechanisms of transcriptional regulation may limit the patterns of gene expression. Such biases may shape both the efficacy of selection and the pattern of individual and species differences. Overall, our data indicate that the prairie vole would be a useful model for exploring how individual differences in gene expression influence complex social behaviors. J. Comp. Neurol. 466:564,576, 2003. © 2003 Wiley-Liss, Inc. [source] DIVERSITY IN THE WEAPONS OF SEXUAL SELECTION: HORN EVOLUTION IN THE BEETLE GENUS ONTHOPHAGUS (COLEOPTERA: SCARABAEIDAE)EVOLUTION, Issue 5 2005Douglas J. Emlen Abstract Both ornaments and weapons of sexual selection frequently exhibit prolific interspecific diversity of form. Yet, most studies of this diversity have focused on ornaments involved with female mate choice, rather than on the weapons of male competition. With few exceptions, the mechanisms of divergence in weapon morphology remain largely unexplored. Here, we characterize the evolutionary radiation of one type of weapon: beetle horns. We use partial sequences from four nuclear and three mitochondrial genes to develop a phylogenetic hypothesis for a worldwide sample of 48 species from the dung beetle genus Onthophagus (Coleoptera: Scarabaeidae). We then use these data to test for multiple evolutionary origins of horns and to characterize the evolutionary radiation of horns. Although our limited sampling of one of the world's most species-rich genera almost certainly underestimates the number of evolutionary events, our phylogeny reveals prolific evolutionary lability of these exaggerated sexually selected weapons (more than 25 separate gains and losses of five different horn types). We discuss these results in the context of the natural history of these beetles and explore ways that sexual selection and ecology may have interacted to generate this extraordinary diversity of weapon morphology. [source] Putting information back into biological communicationJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2010P. CARAZO Abstract At the heart of many debates on communication is the concept of information. There is an intuitive sense in which communication implies the transfer of some kind of information, probably the reason why information is an essential ingredient in most definitions of communication. However, information has also been an endless source of misunderstandings, and recent accounts have proposed that information should be dropped from a formal definition of communication. In this article, we re-evaluate the merits and the internal logic of information-based vs. information-free approaches and conclude that information-free approaches are conceptually incomplete and operationally hindered. Instead, we propose a functional notion of information that follows logically from previous adaptationist accounts. The ensuing definition of communication provides a wider, more inclusive theoretical scope that reflects more accurately the evolutionary scenario shaping animal signals. Additionally, it is a definition better equipped to deal with the extraordinary diversity of animal signals, facilitates the distinction of honest and deceptive signals at a proximate level and accommodates a number of conceptual and practical issues (e.g. redundancy, alerting components) that are lost when we fail to acknowledge the informative content of animal signals. [source] How stupid not to have thought of that: post-copulatory sexual selectionJOURNAL OF ZOOLOGY, Issue 2 2010T. R. Birkhead Abstract Science progresses through ideas or hypotheses; novel ways of viewing the world. If those ideas survive testing, then they are considered ,the truth', or more crucially, truth-for-now, for the essence of science is that if a new idea provides a better explanation of the way the world is, the truth changes. Darwin's idea of evolution by natural selection, published as the Origin in 1859, replaced the earlier truth of physico- or natural-theology introduced by John Ray in 1691. Despite resistance by the church, Darwin's truth gained widespread acceptance, in part due to the efforts of T. H. Huxley, who on reading the Origin said ,How extremely stupid not to have thought of that!' Despite natural selection's enormous explanatory power, there were certain phenomena it apparently could not explain, including female promiscuity. It was only in the 1960s when natural selection was viewed as operating explicitly on individuals (rather than populations or groups), that this changed. Rather than being a cooperative venture between the sexes, sexual reproduction was now viewed in terms of conflicts of interests, and in so doing provided an explanation for female promiscuity (albeit in a male-biased sort of way). Until this point, sexual selection had been concerned exclusively with mate acquisition. With an evolutionary perspective focussing on individuals, it was recognized that sexual selection might continue after insemination, and that rather than competing for partners, males compete for fertilizations. Later it was acknowledged that females, through cryptic processes can also influence the outcome of sperm competition. Today, post-copulatory sexual selection provides explanations for many previously bewildering reproductive traits, including the extraordinary diversity in male and female genitalia, the design of spermatozoa and ova, of seminal fluid and of copulation behaviour itself [source] Cytochromes P450 of insects: the tip of the iceberg,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2001Jeffrey G Scott Abstract The cytochrome P450-dependent monooxygenases are an extremely important metabolic system involved in the metabolism of endogenous compounds and xenobiotics. Collectively, P450 monooxygenases can metabolize numerous substrates and carry out multiple oxidative reactions. The large number of substrates metabolized is due to the plethora of P450 isoforms and to the broad substrate specificity of some isoforms. Monooxygenases of insects have several functional roles, including growth, development, feeding and protection against xenobiotics, including resistance to pesticides and tolerance to plant toxins. This review begins with background information about P450s and their evolution, followed by a discussion of the extraordinary diversity of insect P450s. Given the enormous interest in studying individual P450s, we then provide a synopsis of the different methods that have been used in their isolation and the substrates that are known to be metabolized. We conclude by summarizing the lessons we have learned from the study of individual insect P450s, including their roles in insecticide resistance, plant,insect interactions and insect physiology. However, these studies are just the ,tip of the iceberg'. Our knowledge continues to expand at a rapid pace, suggesting that the next decade will outpace the last in terms of improving our understanding of the cytochromes P450 of insects. © 2001 Society of Chemical Industry [source] | ||||||||||