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Post by johno on Apr 14, 2009 0:45:42 GMT -5
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Post by castanea on Apr 19, 2009 22:44:03 GMT -5
Thanks very much. Epigenetics is fascinating
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Post by grunt on Apr 19, 2009 23:55:12 GMT -5
It also reinforces what Darwin said.
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Post by winter unfazed on May 6, 2009 9:54:54 GMT -5
It reinforces what Lamarck said, really. Sure, Lamarck didn't have a modern day understanding of genetic science (and neither did Darwin), but it's interesting how Lamarckianism is finally coming full circle.
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Post by johno on May 6, 2009 13:49:37 GMT -5
True, but to a very tiny degree. Classical Darwinian genetics still explains well over 99% of inheritance.
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Post by lavandulagirl on May 6, 2009 18:25:05 GMT -5
Thanks for the link, Johno!
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Post by winter unfazed on Jun 12, 2010 13:53:05 GMT -5
Johno, I think you meant "classical Mendelian genetics"...Darwin never even offered an explanation of the "how" in genetics. Darwin was concerned only with the WHY. Lamarck and Mendel were geneticists who explored the how-factor, the mechanisms by which genetics operates.
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Post by keen101 (Biolumo / Andrew B.) on Jun 13, 2010 2:35:22 GMT -5
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Post by nuts on Jun 13, 2010 6:06:56 GMT -5
Both Lamarque and Darwin posed the idea of 'evolution'. The knowledge that species can change over generations was known since ages by plant- and animal breeders.They just extended this knowledge to an extended timescale,they came to the idea that all species emerged as result of minor changes,but accumulated over millions of generations.
Lamarque's explanation was that for exemple the giraffe by trying to extend his neck,transferred the property of longer necks somehow to the next generation. Darwin said that there is genetic variation and that there is a selection for the genomes that result in better adapted individus.
These two explanations don't exclude each other,contrary to the common believe. It all depends where the genetic diversity come from.
In modern science it's commonly admitted that the occurence of diversity is just a random process,thus Lamarque's explanation is commonly rejected.
However,a purely 'random' explanation is not allways satisfactory. The discovery by mendel is a very big step to undertanding of genetiic mechanims,but genetics on a molucair scale is incredibly complex and I think we only understand some small fragments of something extremely vast.
Present knowledge doesn't make it possible to erxplain clearly 'Lamarqien' mechanisms in genetics,hence the rejection of the existance of such.
However the fact that we don't know the mechanisms of Lamarqien processes is,from a scientific point of view not enough to exclude the possibility of the existance.
The article jono pointed to is an indication that there is much more about genetics than the simple mendelian mechanisms.
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Post by pierre on Aug 4, 2010 6:16:06 GMT -5
That classical Mendelian genetics could explains over 99% of inheritance is an old idea.
Actually most geneticians are convinced that Mendel was a lucky man choosing peas as with many plants Mendel laws simply do not apply. Non mendelian genetics, if a relatively recent concept is considered as not rare at all.
Ask i.e. a rose breeder if Mendel laws apply; the answer is to be "at times".
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Post by lmonty on Jan 21, 2011 14:37:12 GMT -5
good article, thanks for sharing
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Post by turtleheart on Oct 24, 2011 10:06:06 GMT -5
yeah thats a good article and i enjoy the topic. i wonder how much epigenetics influences genetic inheritance, understanding that most would say not at all save gene selection. i argue that perhaps just as we have seen horizontal evolution, like in the case of our mitochondrial nucleus, or a virus implanting a bird's allele in a human, that perhaps similarly there is much we do not know of epigenetics, and perhaps it has greater implications for evolution of species than we realize currently.
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Post by gilbert on Feb 5, 2016 19:52:14 GMT -5
I'm wakening up this old thread; what do you all think about epigenetics?
Let's say I had a batch of seed, which I split into two parts. One part was then grown out for a year in Pennsylvania, USA, with tons of rain and clouds. Another was grown in Colorado, USA, with bright sun, high UV, and little rain. And let's say no selection was done on either batch.
Will the Pennsylvanian seeds do better in Pennsylvania then the Coloradan seeds after one year? Five years? Ten years?
If so, is it epigenetics?
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Post by Joseph Lofthouse on Feb 6, 2016 0:18:23 GMT -5
let's say no selection was done on either batch. In that case, the experiment is already finished before it starts. Because, as far as I can tell, it's impossible to grow plants without doing selection. Seeds fail to germinate. They get eaten by bugs before they emerge, or by mice after. Each seed varies slightly from all others, and those slight variations lead to differences in yield, and in seedling vigor, and in number of seeds produces, etc, etc, etc....
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Post by gilbert on Feb 6, 2016 0:20:57 GMT -5
Maybe I should amend it to "conscious selection."
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