Serious Accident in Baker County, Florida Results in Two Deaths and Two Serious Injuries
A vehicle with four occupants drove off of the road on County Road 125 in Baker County, Florida and run into a tree killing two and seriously injuring the other two, including a four year old, according to an article on News4Jax.com. The crash is being investigated by Florida Highway Patrol traffic homicide detectives, but there is no indication yet as to why the car left the road and why the driver was not able to get the vehicle back on the road.
We have written before about the percentage of serious accidents that occur in rural areas as opposed to busier and more populated areas, contrary to what many people might think. This is due to several factors including the fact that drivers lose focus on less crowded rural roads and the roads themselves are often narrower without a shoulder making it easier for a crash like this to occur.
Source: www.florida-injury-attorney-blog.com
A new weapon in the war against HIV-AIDS: Combined antiviral and targeted chemotherapy
EurekAlert! Jun 21 2009 7:15PM GMT
Source: c.moreover.com
The Imaginary Lamarck (The Textbook Letter)
A Look at Bogus "History" in Schoolbooks
Michael T. GhiselinJean-Baptiste de Lamarck (1744-1829) takes a prominent place in many biology textbooks and life-science textbooks, which depict him as the author of a "theory" of evolution based upon the inheritance of acquired characteristics. Lamarck's views, these books say, should be rejected in favor of the theory of evolution by natural selection, propounded by Charles Darwin (1809-1882), because only Darwin's theory is compatible with the findings of 20th-century genetics.
The Lamarck presented in schoolbooks, however, is a fiction -- an imaginary figure who has been fashioned from hearsay and wrong guesses, and who has been replicated in countless books by successive teams of plagiarists. This figure shares very little, except his name, with the Lamarck of history. Textbook-writers have imbued the fictitious Lamarck with an importance that the real Lamarck never had, and they have credited him with ideas that the real Lamarck did not hold. They also have invented a myth in which those ideas are compared falsely with Darwin's ideas, to produce a bogus dichotomy.
Textbooks typically introduce Lamarck with a flourish, as in this passage from Prentice Hall's Biology: The Study of Life:
One of the first theories of evolution was presented by the French biologist Jean Baptiste de Lamarck in 1809. From his studies of animals, Lamarck became convinced that species were not constant. Instead, he believed that they evolved from preexisting species. . . . According to Lamarck's theory, evolution involved two principles. He called his first principle the law of use and disuse. . . . The second part of Lamarck's theory was the inheritance of acquired characteristics. Lamarck assumed that the characteristics an organism developed through use and disuse could be passed on to its offspring.
Much the same material appears in Holt's Biology Today:
In 1809 a French biologist named Jean Baptiste de Lamarck presented an explanation of the origin of species in his work Zoological Philosophy. Lamarck developed a theory of evolution based on his belief in two biological processes:
1) The use and disuse of organs. According to Lamarck, organisms respond to changes in their environment by developing new organs or changing the structure and function of old organs. . . .
2) Inheritance of acquired traits. Lamarck believed that acquired characteristics were passed on to the organism's offspring....
Such claims give many false or misleading impressions, starting with the implication that Lamarck's views were original.
technorati tags: lamarck, biology, inheritance, darwin, traits, genetics, evolution
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From symmetry to asymmetry: Phylogenetic patterns of asymmetry variation
[A. Richard Palmer, PNAS, Dec '96]
From symmetry to asymmetry: Phylogenetic patterns of asymmetry variation in animals and their evolutionary significance
Abstract:
Phylogenetic analyses of asymmetry variation offer a powerful tool for exploring the interplay between ontogeny and evolution because (i) conspicuous asymmetries exist in many higher metazoans with widely varying modes of development, (ii) patterns of bilateral variation within species may identify genetically and environmentally triggered asymmetries, and (iii) asymmetries arising at different times during development may be more sensitive to internal cytoplasmic inhomogeneities compared to external environmental stimuli. Using four broadly comparable asymmetry states (symmetry, antisymmetry, dextral, and sinistral), and two stages at which asymmetry appears developmentally (larval and postlarval), I evaluated relations between ontogenetic and phylogenetic patterns of asymmetry variation. Among 140 inferred phylogenetic transitions between asymmetry states, recorded from 11 classes in five phyla, directional asymmetry (dextral or sinistral) evolved directly from symmetrical ancestors proportionally more frequently among larval asymmetries. In contrast, antisymmetry, either as an end state or as a transitional stage preceding directional asymmetry, was confined primarily to postlarval asymmetries. The ontogenetic origin of asymmetry thus significantly influences its subsequent evolution. Furthermore, because antisymmetry typically signals an environmentally triggered asymmetry, the phylogenetic transition from antisymmetry to directional asymmetry suggests that many cases of laterally fixed asymmetries evolved via genetic assimilation.
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Books on Symmetry from the Science and Evolution Bookshop: UK | US
technorati tags: asymmetry, variation, ontogeny, evolution, development, symmetry, antisymmetry, phyla, directional, origin, genetic+assimilation
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Get Into Currency Trading - Sponsored Link
Ad - www.FOREX.com Jun 21 2009 7:48PM GMT
Source: c.enhance.com
New theory of environmental inheritance ('05 Press Release)
New research has provided evidence for 'environmental inheritance', a radical theory of transgenerational genetic adaptation proposed by Professor Marcus Pembrey of the Institute of Child Health, UCL in the mid 1990's
The latest evidence challenges accepted thinking on genetic inheritance, suggesting that historic events can contribute to some common modern illnesses.
The research, published by the Children of the 90s study based at the University of Bristol in collaboration with Umea University, Sweden, could have far-reaching implications for our understanding of modern health epidemics - such as obesity or cardiovascular disease.
Conventionally scientists believe that how we develop as adults depends on two factors - the genes (DNA) we inherit from our parents, and the environmental influences, such as diet, lifestyle, exposure to pollution from conception onwards.
Professor Marcus Pembrey, who is also head of Genetics at Children of the 90s, says that over the long term, the process of Darwinian evolution by random errors in DNA followed by natural selection ensures that the human race adapts to changes in our environment. But it takes very many generations.
Now there is evidence for another mechanism which no-one had considered... some of the father's own experiences in his childhood are captured in some way by his sperm, so affecting the genes that he bequeaths to his descendants.
[NB Although this is only a press release I've got at least one relevant technical paper which I'll be posting soon - when I find it!]
14th December 2005
technorati tags: research, theory, adaptation, marcus+pembrey, obesity, cardiovascular, disease, genes, dna, parents, diet, lifestyle, pollution, genetics, darwinian, evolution, natural+selection, environment, mechanism, sperm
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Color blindness and contrast perception in cuttlefish (Sepia officinalis) determined by a visual sensorimotor assay
Full paper at above link
Abstract:
We tested color perception based upon a robust behavioral response in which cuttlefish (Sepia officinalis) respond to visual stimuli (a black and white checkerboard) with a quantifiable, neurally controlled motor response (a body pattern).
In the first experiment, we created 16 checkerboard substrates in which 16 grey shades (from white to black) were paired with one green shade (matched to the maximum absorption wavelength of S. officinalis' sole visual pigment, 492 nm), assuming that one of the grey shades would give a similar achromatic signal to the tested green.
In the second experiment, we created a checkerboard using one blue and one yellow shade whose intensities were matched to the cuttlefish's visual system.
In both assays it was tested whether cuttlefish would show disruptive coloration on these checkerboards, indicating their ability to distinguish checkers based solely on wavelength (i.e., color).
Here, we show clearly that cuttlefish must be color blind, as they showed non-disruptive coloration on the checkerboards whose color intensities were matched to the Sepia visual system, suggesting that the substrates appeared to their eyes as uniform backgrounds.
Furthermore, we show that cuttlefish are able to perceive objects in their background that differ in contrast by approximately 15%. This study adds support to previous reports that S. officinalis is color blind, yet the question of how cuttlefish achieve "color-blind camouflage" in chromatically rich environments still remains. [colour]
technorati tags: cuttlefish, color, colour, experiment, checkerboard, blind, camouflage, visual
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Integrated Treatment Programs For Addiction, Mental Health An ...
TransWorldNews Jun 21 2009 7:01PM GMT
Source: c.moreover.com
Balancing Robustness and Evolvability
From PloS Biology:
Balancing Robustness and Evolvability
Richard E. Lenski et al.
One of the most important features of biology is the ability of organisms to persist in the face of changing conditions. Consider the remarkable fact that every organism alive today is the product of billions of generations in which its progenitors, without fail, managed to produce progeny that survived to reproduce. To achieve this consistency, organisms must have a balance between robustness and evolvability, that is, between resisting and allowing change in their own internal states [1 - 3]. Moreover, they must achieve this balance on multiple time scales, including physiological responses to changes over an individual life and evolutionary responses, in which a population of genomes continually updates its encoded information about past environments and how future generations should respond given that record.
Examples of robust biological systems are found at many scales, from biochemical to ecological. At each scale, robustness may reflect the properties of individual elements or, alternatively, the dynamic feedbacks between interacting elements. The expression of some metabolic function, for example, may be robust in the face of temperature change, because an enzyme maintains its shape and specificity across a range of temperatures or because an interconnected network of reactions sustains the supply of product, even when some enzyme fails. A genome may be robust because it encodes proofreading and repair systems that reduce replication errors or because it is organized such that many mutations have little effect on its phenotype. An ecosystem might be robust if it resists the extinction of some keystone species or, if extinction does occur, because surviving species can compensate over physiological, demographic, or evolutionary time scales.
One important question is whether there exists a single unifying mathematical framework that can encompass such diverse examples of biological robustness. Might new insights come from such a conceptual unification, or will future understanding require detailed analyses of specific cases? Across the different scales, recurring mechanisms for achieving robustness - including redundancy of component parts and negative feedbacks - might serve as organizing principles. Yet, similarities in mechanism could mask important differences in the evolutionary origins of those mechanisms. At the level of genes in genomes or of cells in multicellular organisms, it is reasonable to suggest that redundancy evolved by natural selection to maintain some functional capacity in the face of perturbation [4]. But whereas species redundancy could also be critical for robustness of ecosystem functions, differences in redundancy might be an emergent property rather than an ecosystem-level adaptation, because selection generally acts at lower levels (but see [5] for another view).
Continued at "Balancing Robustness and Evolvability" [A modified version of this post (with background info) will be posted to the "General Evolution News" category]
Technorati: balancing, robustness, evolvability, biology, organisms, conditions, generations, progeny, genome, repair, systems, framework, genes, evolutionary, origins, multicellular, demographic, physiological, ecosytem, redundancy, richard, e, lenski, adaptation, phenotype, natural selection, emergent, property, level, keystone, species, extinction
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Swine flu can turn more lethal in winter: Scientists
The Hindu Jun 21 2009 7:04PM GMT
Source: c.moreover.com
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