2,190 research outputs found
Darwinism and Organizational Ecology: A Reply to Reydon and Scholz
In an earlier article published in this journal I challenge Reydon and Scholz's (2009) claim that Organizational Ecology is a non-Darwinian program. In this replay to Reydon and Scholz's subsequent response, I clarify the difference between our two approaches denoted by an emphasis her on the careful application of core Darwinian principles and an insistence by Reydon and Scholz on direct biological analogies. On a substantive issue, they identify as being the principle problem for Organizational Ecology, namely, the inability to identify replicators and interactors "of the right sort" in the business domain; this is also shown to be easily addressed with reference to empirical studies of business populations.Peer reviewedFinal Accepted Versio
ACCOUNTING FOR BIOLOGICAL DIVERSITY 1
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72778/1/j.0014-3820.2003.tb00329.x.pd
Evolution for the Next Generation
Do you want to know about evolution? Brian and Deborah Charlesworth provide an excellent and concise account of the core issues for a broad range of reader
The Origin and Distribution of Clonal Diversity in \u3ci\u3eAlsophila pometaria\u3c/i\u3e (Lepidoptera: Geometridae)
A survey of spatial and temporal variation in the frequency of electrophoretically defined genotypes in the geometrid moth Alsophila pometaria revealed a high diversity of uncommon or rare asexual genotypes and clinal distributions of two of the more common clones. There was substantial year-to-year variation in genotype frequencies in seven of eleven sites. Progeny tests have revealed that sexual reproduction is uncommon in two populations and that new asexual genotypes arise from the sexual population. The recurrent origin of asexual genotypes is likely to account for the high genetic and ecological diversity of the asexual contingent of this species’ populations, in contrast to the lower genetic diversity in some obligately asexual species in which such recruitment does not occur
Variation in Population Sex Ratio and Mating Success of Asexual Lineages of \u3ci\u3eAlsophila pometaria\u3c/i\u3e (Lepidoptera: Geometridae)
Populations of Alsophila pometaria (Harris) are largely gynogenetic and composed of asexual females that must mate with a conspecific male to reproduce. Within this asexual contingent, there are a variety of electrophoretically defined multilocus genotypes. In this study we found that populations differ in sex ratio. We also found that there is an indication of differential mating success among asexual genotypes in a population of A. pometaria
Survivorship and Growth of Sexually and Asexually Derived Larvae of \u3ci\u3eAlsophila pometaria\u3c/i\u3e (Lepidoptera: Geometridae)
A substantial body of theory is devoted to understanding the relative advantages of sexual and asexual reproduction. It is generally understood that asexual forms potentially have a higher rate of reproduction because they save the cost of producing males. The micro-evolutionary consequences of sexual and asexual reproduction are less clear. Sexual reproduction generates abundant genotypic diversity which may be adaptively advantageous (Williams 1975; Maynard Smith 1978). Asexual reproduction may perpetuate combinations of genes that are co-adapted (Templeton 1979), heterotic (Suomalainen et al. 1976; White 1979), or specialized (Vrijenhoek 1979, 1984). Thus, it is possible that the fitness of a sexual population may be lower than an asexual, in part, because recombination tends to break up especially favorable genotypes (Williams 1975; Hebert 1978). If it is generally observed that asexual reproduction has an immediate adaptive as well as a reproductive advantage, then it is difficult to see how sexual reproduction can be maintained by short-term advantages (Williams 1975).
A comparison of closely related sexual and asexual forms is a promising avenue of research to evaluate experimentally the consequences of both modes of reproduction (Maynard Smith 1978). In this study, geometrid moth larvae (Alsophila pometaria) derived from both kinds of reproduction were reared on different host plants. The goal was to assess larval viability and growth in an ecologically relevant context and thus partially characterize the fitness of sexual and asexual reproduction
Variation in Population Sex Ratio and Mating Success of Asexual Lineages of \u3ci\u3eAlsophila pometaria\u3c/i\u3e (Lepidoptera: Geometridae)
Populations of Alsophila pometaria (Harris) are largely gynogenetic and composed of asexual females that must mate with a conspecific male to reproduce. Within this asexual contingent, there are a variety of electrophoretically defined multilocus genotypes. In this study we found that populations differ in sex ratio. We also found that there is an indication of differential mating success among asexual genotypes in a population of A. pometaria
Progress on the Origin of Species
Two new books on speciation update the classic texts by Mayr and Grant and help set the stage for a renaissance of research into one of the most important processes in evolutio
Shaping Robust System through Evolution
Biological functions are generated as a result of developmental dynamics that
form phenotypes governed by genotypes. The dynamical system for development is
shaped through genetic evolution following natural selection based on the
fitness of the phenotype. Here we study how this dynamical system is robust to
noise during development and to genetic change by mutation. We adopt a
simplified transcription regulation network model to govern gene expression,
which gives a fitness function. Through simulations of the network that
undergoes mutation and selection, we show that a certain level of noise in gene
expression is required for the network to acquire both types of robustness. The
results reveal how the noise that cells encounter during development shapes any
network's robustness, not only to noise but also to mutations. We also
establish a relationship between developmental and mutational robustness
through phenotypic variances caused by genetic variation and epigenetic noise.
A universal relationship between the two variances is derived, akin to the
fluctuation-dissipation relationship known in physics
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