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modern synthesis

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modern synthesis

Postby alexpdys » Sat Oct 06, 2012 1:46 pm

There's a lot of talk about the modern synthesis being in need of an update. However, as far as I know, there is no well defined and accepted common consensus (at least as a consensus from wright, fisher, huxley, haldane, simpson, etc etc, i.e those accredited retrospectively with the modern synthesis) as to what the modern synthesis "is". If there is no consensus view, how can we say it is in need of an update?

Is it true that the only time that "modern synthesis" as a term was used by those above etc was by Huxley in "Evolution: the modern synthesis".

Modern synthesis was not a restrictive as current people would have you believe. Is it correct that it, in simple terms, consisted of 1) Inheritance is particulate in nature 2) this accounts for variation within populations 3) natural selection acts on particulate inheritance 4) there are other mechanisms of evolution other than natural selection e.g. genetic drift, migration HOWEVER these are not responsible for adaptation.

if that is the case, I don't see why the modern synthesis is in need of an update. It still seams a reasonable framework for biology including evo-devo etc.

Thoughts?
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Postby alexpdys » Sat Oct 06, 2012 2:00 pm

N.b two extra points.

1) lamarkianism was discarded by the modern synthesis. Yes that's true. There's a lot of talk of neo-lamarkianism currently, however to use the term neo-larmakianism is misguided. IAC, e.g. epigenetic changes, is only one part of lamarkianism. IAC may be able to result in evolution in the strict sense of descent with modification from one generation to the next. However IAC does not result in change in gene frequencies/composition 2) speciation. It is incredibly unstable, and in a strict sense therefore does not show true inheritance, i.e over multiple generations. One example given for IAC in the context epigenetic changes is pup grooming. A pup not licked/groomed by it's mother will not lick/groom it's own offspring. And so on and so on down the line, generation after generation. However this cycle is broken if a second generation pup is removed from it's mother. Is that really inheritance of acquired characteristics therefore?

2) saltatationism was discarded by the modern synthesis. No that is not true, it wasn't. I t was simply not believed to play a major part in evolution and speciation. I haven't seen any evidence to the contrary. Does anyone know of any?
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Re: modern synthesis

Postby Forests » Sat Oct 06, 2012 4:01 pm

(at least as a consensus from wright, fisher, huxley, haldane, simpson, etc etc, i.e those accredited retrospectively with the modern synthesis) as to what the modern synthesis "is". If there is no consensus view, how can we say it is in need of an update?


There was a consensus of what the neo-Darwinian synthesis was, Ernst Mayr discussed it in his book and so did Julian Huxley. It put a primary role for natural selection, mixed with mutation and later genetic drift. It also worked in a dogmatic gradualistic framework and denied that saltationism could occur.


lamarkianism was discarded by the modern synthesis. Yes that's true. There's a lot of talk of neo-lamarkianism currently, however to use the term neo-larmakianism is misguided. IAC, e.g. epigenetic changes,


Yes it was discarded and ignored by the modern synthesis, but theres no evidence neo-Lamarckism is wrong. Recent papers conclude that certain mechanisms for evolution fit the criteria to be described as "Lamarckian".

saltatationism was discarded by the modern synthesis


Yes it was discarded and ignored by the dogmatic neo-Darwinian synthesis. But there are many scientific papers out which show the reality of saltationism as opposed to a strict gradualistic framework.

Modern synthesis was not a restrictive as current people would have you believe


Yes it is restrictive and very limited. Those within the neo-Darwinian synthesis only advocate a few mechanisms and ignore the rest.

I don't see why the modern synthesis is in need of an update.


Modern synthesis is 1940's. Science is not static. It is not possible to squeeze so many mechanisms into a limited framework. Things like niche construction fit in better with an extended or new synthesis.

There have been multiple threads about this already on this forum and other forums, see the thread evolution is not Darwinian for scientific papers claiming the neo-Darwinian synthesis is outdated etc.
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