29 de November de 2015 at 14:13 #2509
Our findings suggest that unpredictable food access caused seemingly adaptive responses in feeding behavior, which may have been transmitted to the offspring by means of epigenetic mechanisms, including regulation of immune genes. This may have prepared the offspring for coping with an unpredictable environment. Trans missions of information across generations which does not involve traditional inheritance of DNA-sequence is often referred to as soft inheritance or ‘Lamarckian inheritance’. The group of researchers at The University of Linköping again highlighted the apparent link between food intake and cross-generational inheritance of acquired traits. This link has been shown before in studies of human populations who have experienced starvation, where epigenetic factors have altered the functioning of genes. These changed epigenetic factors appear to show traits in the next generation such as an increased occurrence of diabetes. The process of methylation is thought to be behind such changes. Several historians have argued that Lamarck’s name is linked somewhat unfairly to the theory that has come to bear his name, and that Lamarck deserves credit for being an influential early proponent of the concept of biological evolution, far more than for the mechanism of evolution, in which he simply followed the accepted wisdom of his time. Lamarck died 30 years before the first publication of Charles Darwin’s Origin of Species. According to Stephen Jay Gould, if Lamarck had been aware of Darwin’s proposed mechanism of natural selection, there is no reason to assume he would not have accepted it as a more likely alternative to his own mechanism. Note also that Darwin, like Lamarck, lacked a plausible alternative mechanism of inheritance the particulate nature of inheritance was only observed by Gregor Mendel somewhat later, and published in 1866. Its full significance was not appreciated until the Modern evolutionary synthesis in the early 1920s.
An important point in its favor at the time was that Lamarck’s theory contained a mechanism describing how variation is maintained, which Darwin’s own theory lacked. Several recent studies, one conducted by researchers at MIT and another by researchers at the Tufts University School of Medicine, have rekindled the debate once again. As reported in MIT’s Technology Review in February 2009, “The effects of an animal’s environment during adolescence can be passed down to future offspring. The findings provide support for a 200-year-old theory of evolution that has been largely dismissed, Lamarckian evolution, which states that acquired characteristics can be passed on to offspring. For us dog men the conclusion is however quite simple of course, the better the environment and care and, in my humble view this especially related to (environ)mental, emotional and psychological experiences this is of the utmost importance not only for our living and working dogs but even more so it seems as in relation to their offspring.All this might expel too in my view the myth of keeping dogs under harsh conditions as to toughen them up,A widely held believe. I personally believe however that kennels with about ten or so dogs, or even keeping them as house dogs perform overall much better then kennels with a hundred or so dogs due to the fact that the dogs psychological and emotional or mental health is WAY better. Let’s hope that all this will be passed on to future generations of our great breed too !
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